Alzheimer

Concerns about the paired associates learning test for dementia

Shibley Rahman 0 Comments

To begin to understand how a cathode-ray TV set works, I could remove one component called the “transistor”, and the picture disappears. It would be an incorrect conclusion to say that the purpose of that transistor is to produce the picture. However, I could argue correctly that the transistor was somehow part of the system required to produce the picture.

If I showed the transistor was particularly “hot” while the TV set was on, producing a picture, it might be reasonable for me to conclude the transistor was involved in producing the picture.

This is the sort of basic approach still used to work out what is going on in the brains and minds of people with Alzheimer’s disease, typical presentations of which might be memory problems. You can see whether removing parts of the brain in humans produces similar effects to the problems in thinking found in Alzheimer’s disease. Or alternatively, you could just try to look at the system of components in the brain which might be contributing to memory in brains working normally.

TV set

Whatever, it’s a puzzle. In this particular case, it’s a puzzle to solve correctly.

An innovation culture in the diagnosis of Alzheimer’s disease

David Cameron praised Cambridge Cognition’s work in developing new innovative tests for Alzheimer’s disease in the G8 summit held towards the end of last year.

There has been concern that some individuals with Alzheimer’s disease do not receive their diagnoses in a particularly fast way. A number of explanations for this have been offered, including medical personnel not being able to spot the symptoms of Alzheimer’s disease easily.

It is also helpful to understand what an “innovation” is. An innovation might be a product which enables you do something much more easily, and depends for its success popular uptake by the user. Strictly speaking, paper was an innovation too. However, the rise in cost of diagnosing Alzheimer’s disease, arguably, is an intriguing example of “Baumol’s cost disease“.

Individuals with Alzheimer’s disease have memory problems which are typically not thought to be qualitatively similar to those found in ageing elderly individuals. Often such people have real problems in navigating around environments. It is clearly a very laudable aim to have a bedside test which might be able to alert a physician to an underlying memory problem in Alzheimer’s disease.

The benefits and concerns, and my passing involvement

There are a number of important caveats here. Not all dementias are Alzheimer’s disease. There are in fact hundreds of dementias, some of which are reversible. Whatever test is used, the test should be sensitive enough to identify reliably a genuine thinking problem in Alzheimer’s disease, but should not be so ‘broad brush’ the test also misattributes memory problems, say found in the ‘mild cognitive impairment’ or even depression, to Alzheimer’s disease. Such mislabelling can perceivably cause distress, and cause people to be caught up in the medical system for further lengthy tests when they should not have been in the first place. On the other hand, it is of concern that the diagnosis might be missed in some people, and hence the drive from the Department of Health and the Alzheimer’s Society in “The Prime Minister’s Dementia Challenge”.

I wish Cambridge Cognition well, not least because I have worked with CANTAB whilst a graduate student at the University of Cambridge. In fact, some of my papers are cited in their bibliography. Their search facility is here.

Bibliography

The CANTABmobile “paired associates learning” test

To explain the “paired associates learning” test from first principles, and I’m not using actual screenshots, imagine me presenting you with a number of blank boxes dotted around the screen.

Fig 1

And I open each box in turn and reveal a shape to you. I can present the problem with a varying number of shapes.

Fig 3     Fig 2

After showing you all the shapes, I then present to you a shape and ask you to identify the box in which it was first presented.

Fig 4

Cambridge Cognition in welcoming the Draft National Plan to Address Alzheimer’s disease in my opinion set out entirely correctly the advantages of this computerised testing battery; including fast, not culturally biased, not heavily loading on language, norm-referenced, culturally unbiased, and easy-to-use.

The reasoning behind it being sensitive to early Alzheimer’s disease – but what about mild cognitive impairment?

To understand why the narrative for the test being so attractive in early Alzheimer’s disease, you have to understand that this test has been found to be sensitive to functions of particular brain areas. If you chop out bits of the brain near the front of the head (frontal cortex) or near the ear (temporal cortex), performance on this task is impaired, as Prof Adrian Owen showed when he was a post-doctoral fellow (paper here). With hindsight, perhaps Owen should have looked at the effects of other brain areas further back in the brain, such as the parietal cortex, which are also now thought to be important in memory for spatial cues.

A consistent finding has been loss of brain cells in the “entorhinal cortex”, in the temporal cortex, early in Alzheimer’s disease (see for example here). Therefore, that the paired associates learning test should identify memory problems in early Alzheimer’s disease immediately makes intuitive sense.

But the issues I feel are much more complicated, and I wish Cambridge Cognition well in clarifying them.

If it’s not Alzheimer’s disease, what else could be causing the memory problems?

One possibility is “mild cognitive impairment”. It is described, for example on the authoritative Mayo Clinic website, that:

“Mild cognitive impairment (MCI) is an intermediate stage between the expected cognitive decline of normal aging and the more serious decline of dementia. It can involve problems with memory, language, thinking and judgment that are greater than normal age-related changes. If you have mild cognitive impairment, you may be aware that your memory or mental function has “slipped.””

David Hart, Senior Business Development Manager of Cambridge Cognition, kindly sent Dr Peter Gordon the rationale for the use of the CANTAB task by Dr Andrew Blackwell, their Chief Scientific Officer (as produced on Peter’s blog here).

Cambridge Cognition concede that distinguishing between MCI and Alzheimer’s Disease “is difficult”, but this is a distinction that must be arrived at otherwise a test potentially will give “false positives” – but no test is perfection, and it basically is impossible to strive for perfection. What we all trying avoid is where a test for possible dementia itself is expensive followed by a further expensive investigation to show the original result was a false positive – or as the Express euphemistically called it recently, “Dementia diagnosis proved wrong by new super scanner”.  (It is important to state clearly here that no details are given how a diagnosis had been arrived at previously for Ros Davies.)

To give them credit, Cambridge Cognition cite the Chandler et al. (2008) paper, but the full citation of this is “Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association Volume 4, Issue 4, Supplement , Pages T551-T552, July 2008″ – i.e. it is a supplement of abstracts not full papers. This particular abstract can be viewed here.

It is hoped that this full study will have been published elsewhere, and if so Cambridge Cognition will need to update their website with the full paper. Notwithstanding this, the numbers of individuals in each group are disappointingly low: there are seventeen with putative MCI and twelve with putative Alzheimer’s disease.

Is this task actually sensitive and specific?

However, the discussion by Dr Andrew Blackwell and colleagues in his 2004 paper is useful. I have more than a passing interest in that paper as the main author on that paper was one of my PhD supervisors at Cambridge, Prof John Hodges. John has also kindly written one of my three Forewords for my book, “Living well with dementia” to be published on January 14th 2014.

Blackwell remarks correctly that this task has been used to distinguish between unipolar depression and Alzheimer’s disease in Rachel Swainson’s study. But is this enough? I looked to the previous Beats study in “geriatric depressive”, and there was nothing forthcoming there. How confident can one be that only early patients with Alzheimer’s disease, and not those severely depressed or with an underactive thyroid, will perform abnormally on the PAL? Personally, I’m not at all confident yet, despite the Swainson study, but these fears can easily be allayed with a sensitivity/specificity study of much higher power.

Blackwell is however correct in citing my study with Dr Andy Lee in that patients with semantic dementia and behavioural variant frontotemporal dementia are relatively unimpaired, though the clinical presentations of the frontotemporal dementias can be quite clearly different in the clinic from Alzheimer’s disease. Completing the double dissociation, I did find that the behavioural variant of frontotemporal dementia did present with rather specific risk-taking decision-making of its own.

But in the meantime the comparison with frontotemporal dementias is useful.

Lee

Nonetheless, this approach is being rolled out.

On 28 June 2013, the use of CANTABmobile was described as follows:

“The Guildford and Waverley Clinical Commissioning Group (CCG) is leading the use of an innovative new iPad-based memory assessment  system as part of a national push to decrease dementia diagnosis waiting times and streamline the referral process.   Accessed through NHS medical professionals, CANTABmobile enables GPs to test a patient’s episodic memory through an easy to use and administer 10-minute cognitive assessment.”

The CANTAB paired associates learning test is pictured under the heading “intuitive touchscreen interface”. if you go to “download information” on this page.

It was covered in the national media here: for example Victoria MacDonald’s report (this page provides a criticism of another report by Victoria MacDonald this time over Prof Brian Jarman’s proposed HSMR data by NHS Consultant, Dr Jacky Davis).

So what does this task test?

In understanding how the task works in reality, I found a paper where Prof Ed Bullmore and colleagues put individuals with Alzheimer’s disease and control subjects performing the task into a scanner really helpful.  Bullmore and colleagues frontloaded their discussion with the following comment:

“Independent of the level of difficulty, the majority of subjects in both groups activated a network of brain regions, including the anterior cingulate, lateral, and medial occipitoparietal and frontal cortices, during successful encoding and retrieval.”

This is interesting as it doesn’t point to the usual suspects of the narrative, i.e. the entorhinal cortex and other parts of temporal lobe. Even Andrew Blackwell had described how the damage to the entorhinal cortex might possibly account dor deficits on the paired associates task:

“The transentorhinal region is a complex transitional area located between the entorhinal region proper and the adjacent temporal isocortex. It has been suggested that damage to this site in early [Alzheimer’s disease] disrupts reciprocal connections with the hippocampal formation and that this disruption underlies deficits in episodic memory.”

But on reflection is this wholly a surprise? Ed Bullmore and colleagues from their results, also from Cambridge, discuss that the lateral parietal activations reported during episodic memory tasks are thought to reflect recognition processes and retrieval processing of spatial information. Medial parietal activity has been proposed to underlie imagery and retrieval success.

I don’t feel it’s altogether surprising given what is known about the build-up of pathology in Alzheimer’s disease, either. The authors of one study looking at this report that:

“[18F]FDDNP-PET signal was significantly higher across widespread cortical regions in subjects with poorer neuropsychological test performances. Strong correlations were seen in the entorhinal, orbitofrontal, and lateral temporal cortices, temporoparietal and perisylvian language areas, parietal association cortices, and much of the dorsolateral prefrontal cortex.”

But the Sahakian lab elsewhere did find something was up with the parts in “the hippocampus and associated structures”, i.e. the structures in the temporal lobe, in this task.

But that study was only comparing MCI with normal controls. It did not include patients with Alzheimer’s disease. This is relevant, if you happen to believe that MCI ‘predates’ Alzheimer’s disease, as the authors of that study clearly do:

“Later in the course of the transition from MCI to clinical Alzheimer’s disease, functioning of the MTL deteriorates further to an extent that such compensatory activity is no longer possible. The hyperactivity in early MCI might then represent a possible predictor or biomarker of the progression to Alzheimer’s disease.”

But in the real world this is far from clear.

However, the evidence of progression of MCI (mild cognitive impairment) to DAT is currently weak. It might be attractive to think that MCI is a preclinical form of dementia of Alzheimer Type, but unfortunately the evidence is not there to back this claim up at present: most people with MCI will not progress to dementia even after ten years of follow-up (Mitchell and Shiri-Feshki, 2009). Drug companies have been trying hard to push the identification of “biomarkers”, possibly subtle psychological ‘deficits’, scan results or changes in substances in the fluid surrounding the brain (or cerebrospinal fluid). It is no accident that psychological testing and biomarkers were heavily promoted in David Cameron’s G8 dementia speech in Lancaster House at the end of last year.

In summary, I don’t think it can be taken as red that entorhinal cortex problems are causing the observed deficits in the CANTABmobile paired associates learning task.

Conclusion

Overall, my personal view is that the deficits on the CANTAB paired associates learning task are real in early Alzheimer’s disease, but possibly not for the reasons felt by some in their groups. Above all, I don’t care as such, as long as greater numbers of people benefit from a correct diagnosis of Alzhemer’s disease, but I do feel that the logic in their reasoning has gone a bit awry.

My academic viewpoint is utterly irrelevant actually, as above all I wish the whole of the medical profession well in their “war against dementia”.

I’d be the first to admit I’ve got it wrong. I am simply raising the issues in a constructive way that I hope is beneficial for the public interest.

But Dr Mitul Mehta, Reader in Neuroimaging at the IoP, does have his concerns.

Blurred lines in English dementia policy – privatisation in all but name

Shibley Rahman 0 Comments

In case you don’t like the soundtrack, here are the slides.

To some extent, Europe resolved our dispute about whether we should aspire to an ‘early diagnosis’, or ‘timely diagnosis’ for dementia. The overall consensus from the European ALCOVE project was that a diagnosis should be timely, in keeping with the needs of the person with a dementia, his friends, his family or his carers.

This was an extremely helpful move in English policy, although the road had not been that clear.

One blurred line in the public was how dementia so massively became conflated with all memory problems in the elderly. Whilst it was argued that the memory problems in Alzheimer’s disease should no longer be passed off as ageing (and indeed there are strong cultural pressures elsewhere for calling dementia ageing), there was some concern from GPs that older people thought their memory problems were dementia because of the widespread media campaign. Many of these individuals were later to arrive at a diagnosis of minor cognitive impairment, underactive thyroid, or depression. Given that there are hundreds of different causes of dementia which can affect any part of the brain and brainstem (though they all tend to start off in different areas), it’s not altogether surprising that some of the dementias don’t present with memory problems at all.

The drive to make the diagnosis is almost certainly going to be affected by the policy from NHS England to achieve ‘ambitions’ for increasing dementia diagnosis rates. The evidence from the MRC study at Cambridge has demonstrated that this prevalence has in fact been falling over some decades, so there is serious concern that a drive to increase dementia rates will lead to a large number of false diagnoses in 2014. This is definitely one to watch, as a false diagnosis can lead to very serious harmful repercussions. Nonetheless, the number of people who have a MMSE in the region of 10-15 on initial diagnosis is, arguably, staggering, and blatant lack of diagnoses of more obvious presentations of diagnosis most people would agree is unacceptable.

The spotlight in G8, and certainly the presence of corporates there, will lead to increased scrutiny of those people who financially have much to gain from an early diagnosis. An early diagnosis may indeed lead to someone ‘accessing care’, even that care results from a personal health budget with treatments which are not proven clinically from the evidence. The direction of this particular plan depends how far individualised consumer choice is pushed in the name of personalisation. Genetics, neuropsychologists, and pharmaceutical private sector companies wishing to monitor the modest effects of their drugs on substances in the brain all stand to capitalise on dementia in 2014, much of which out of the NHS tax-funded budget. This of course is privatisation of the NHS dementia policy in all but name. One thing this Government has learnt though is how to make a privatisation of health policy appear popular.

Despite corners being cut, and the drive to do ‘more for less’, it will be quite impossible to avoid making a correct diagnosis in individuals thought to have a dementia in the right hands. A full work-up, though the dementia of the Alzheimer type, is the most common necessitates a history of the individual, a history from a friend, an examination (e.g. twitching could be associated with the motor neurone disease variant found in one of the frontotemporal dementias), brain scan (CT/MRI/PET), brain waves (EEG), brain fluid (cerebrospinal fluid), bedside psychology, formal cognitive psychological assessment, and even in some rarely a brain biopsy (for example for variant Creutzfeld-Jacob or a cerebral inflammatory vasculitis).

Analysis by paralysis is clearly not desirable either, but the sticking point, and a blurred line, is how England wishes to combine increasing diagnostic rates; and making resources available for post-diagnosis support; making resources available for the diagnosis process itself including counselling if advised. As the name itself ‘dementia’ changes to ‘neurocognitive impairment’ under the diagnostic manual DSM in 2015, the number of people ‘with the label’ is likely to increase, and this will be ‘good news’ for people who can capitalise on dementia. The label itself ‘neurocognitive impairment’ itself introduces a level of blur to the diagnosis of dementia itself.

The general direction of travel has been an acceleration of privatisation of dementia efforts, but this to be fair is entirely in keeping with the general direction of the Health and Social Care Act (2012). A major question for 2014 is whether this horse has now truly bolted?

The G8 dementia Summit: the comparison with the botched NHS reforms is striking

Shibley Rahman 0 Comments

frail hands

This week,  to great fanfare, the G8 hosted its summit on dementia. Indeed, that the G8 were discussing a single condition was indeed remarkable. That they were joining forces to consider working together on this inspired hope.

What was unforgiveable was the sheer volume of myths about dementia which were pedalled though by the media. Prof Alistair Burns to his credit gave an answer in an interview by Emily Maitlis explaining how dementia prevalence rates appeared to be falling, in response to the backdrop set up by media memes such as ‘timebomb’. Many were left extremely angry on account of the lack of balance, completely distorting the picture such that any idea of someone ‘living well with dementia’ became a rarity.

What was not expected was a sanitisation of advanced dementia, but even there there was not a discussion of end of life care. In fact, there generally was no discussion of a minimum safe level of health and social care in any of the countries. The media pushed hard ‘a cure for dementia by 2025′, which major Alzheimer’s societies had signed up to. The claim is complete and utter rubbish, as there are over a hundred different types of dementia; the public were unashamedly being sold a pup.

The English health system, the National Health Service, has an obsession with ‘efficiency’. So much so it will happily fork out to pay one for one junior doctor covering all the general medical hospital every night for a week, and that junior doctor doesn’t stop all night. Sometimes that junior doctor will be expected to cover the wards too. Cover by nurses can be equally ‘lean’ during the weekends too.

The obsession with measuring ‘I want good care’ and regulation is akin to a teacher who has forgotten to teach but can set regular assessments. When the system is set up to run everything with much less doing a lot more, it’s possible something has got to give. And this is of course precisely what happened at Mid Staffs.

And yet out of the blue there appeared a 493 page document ultimately called the Health and Social Care Act (2012) which had nothing to do with this most important point about patient safety. There is not even a single clause to do with patient safety (unless  you include the clause abolishing the National Patient Safety Agency). The medical Royal Colleges were not involved. The BMA was not involved. And yet the Act of parliament, outsourcing and privatising the NHS, is just what the Corporate ordered.

This is what is known in the (business) trade as an ‘opportunity cost’ where money and efforts could have been better spent elsewhere. In this particular case, despite a promise of ‘no top reorganisation’, there was a £3bn reorganisation.

When attending a medical ward, you have to go to the sick patient first. You have to prioritise. If there had to be an unannounced reform of the NHS, outsourcing it was not the priority. The latest survey even shows that the public don’t especially like private providers doing NHS work.

Likewise, the priority for dementia care should have been investment in the social capital of caring. Too often carers are embattled with the biological, financial and legal considerations of caring. Many carers are themselves on zero-hours contracts. The G8 dementia summit was a great opportunity to confront that.

It didn’t. Instead, with alarming synchrony, the G8 leaders came together to sing off the corporate script. Vivienne Parry with effortless ease choreographed a seemingly spontaneous discussion about well rehearsed arguments for the need for ‘big data’, global data sharing, genomics, and personalised medicine, for much of the day. Prevention was of course discussed, but this is of course intimately wound up with the collection of information about the person, and the use of that other pet subject, biomarkers.

And more research is not better research, in the same way bigger information is not better information. If research monies are diverted into data analysis, genomics and personalised medicine, these monies will be diverted away from research into caring for example. One wonders whither the ‘cure for dementia’ will actually go, unless they have another fifteen years to look at slowing the progression of Alzheimer’s disease. The evidence that cholinesterase inhibitors, a class of drugs used to treat symptomatically memory and attention problems in Alzheimer’s disease, has a beneficial effect on slowing disease progression is as low as it possibly can be after nearly 20 years of expensive research in this area.

The G8 summit, like the Health and Social Care Act, was ‘corporate capture’ at its best, so if you’re angry, well done, that is the appropriate emotional reaction!  If you were wondering if you’d accidentally missed the discussion of carers and how they would be involved until 2025, don’t worry, you hadn’t. They weren’t there.

Is a new sophisticated brain scan desirable to diagnose dementia?

Shibley Rahman 1 Comment

Amyloid plaques

Wouldn’t it be lovely Prime Minister, David Cameron MP, could announce a breakthrough which nails the problem of the diagnosis of Alzheimer’s disease?

The definitive diagnosis of dementia of the Alzheimer type (DAT) comes post mortem (though in practice various techniques while the patient is alive can be used to tell whether a patient has a type of dementia).

The full armoury of tests includes thinking tests or cognitive neuropsychology, a sample of the fluid from the spine (cerebrospinal fluid), the clinical history and examination of the patient, brain waves (the EEG), or even (rarely) a brain biopsy; that’s even before considering types of scan, like the ‘CT scan’, the ‘MRI scan’, or ‘functional scan’.

The trick of the clinician, varying with levels of expertise, is to make the diagnosis reliably such that a person living with dementia might be able to ‘access’ appropriate care in the system; and those without dementia aren’t given an incorrect label of ‘dementia’.

DAT is one of the hundreds of causes of dementia (although most of the media use ‘Alzheimer’s Disease’ and dementia unhelpfully synonymously.)

Amyloid build-up and the diagnosis

There has been a popular idea that the build up of a substance called amyloid which builds up in the brain might hold the clue to early diagnosis of Alzheimer’s Disease.

In recent years, the emphasis has swung to ‘timely diagnosis’, with the national clinical lead for dementia, Prof Alistair Burns, emphasising that the diagnosis should be made at a time appropriate for the person himself or herself.

A ‘quick fix’ in a test for DAT seems very attractive, but it’s important to remember that the dementia of the Alzheimer type is only one (but the most common) cause of dementia across all age groups.

How to use the test in a safe way

The way in which this diagnosis could be made has also come under scrutiny.  A method which uses a radioactive label to which at how much label can bind to abnormal amyloid in the brain, to be practical, should not be excessively time-consuming to administer. It also should not be prohibitively expensive.

Also critically, it should be reliable. In other words, it shouldn’t show up ‘positives’ in otherwise well people, who never go onto develop dementia. A critical problem is that there are many causes of memory loss in older people, including of course depression.

To make things even more complicated, there is a very interesting group of people whose thinking and memory are normal, even late in life, yet their brains are full of amyloid beta plaques that appear to be identical to what’s seen in dementia of the Alzheimer type. How this can occur is an important clinical research question.

Hard plaques made of a protein called amyloid beta are always present in the brain of a person diagnosed with the dementia of the Alzheimer type.  But the simple presence of plaques does not always result in impaired thinking and memory. In other words, the plaques are necessary – but not sufficient – to cause DAT.

Is it the type of amyloid which matters?

Earlier this year a paper was published in the prestigious journal in the US (Esparza TJ, Zhao H, Cirrito JR, Cairns NJ, Bateman RJ, Holtzman DM, Brody DL. (2013) Amyloid-β oligomerization in Alzheimer dementia versus high-pathology controls. Ann Neurol. 73(1):104-19. doi: 10.1002/ana.23748. Epub 2012 Dec 7.)

An important clue may come from still come from a form of amyloid beta, but not necessarily in the form of plaques. Instead, smaller molecules of amyloid beta appear more closely correlated with whether a person develops symptoms of dementia; these are called “amyloid beta oligomers“.

Earlier this year, this group developed a way of measuring  these amyloid beta oligomers in minute quantities, without binding to similar things.

These amyloid beta oligomers were detected in samples of brain from patients with DAT and nondemented patients with amyloid plaque pathology. However, amyloid beta oligomer concentrations in samples from patients with DAT were tightly correlated with amyloid plaque coverage (correlation very high), but this relationship was weaker in those from nondemented patients (correlation very low) despite equivalent amyloid plaque pathology.

The results raise the intriguing hypothesis that the linkage between plaques and oligomers may be a key pathophysiological event underlying DAT.

This test would be clearly potentially profitable for people who have developed this test, and the critical issue is whether if you scan real patients whether the amount of radioactive binding will reliably distinguish between people with dementia and those without.

Would a new brain scan be helpful?

Looking for amyloid in people who might be developing dementia has been a story going on for ages. The Telegraph newspaper reports a “breakthrough” in a scan, but the description is that of plaques (leading to the possibility of people having lots of plaques found on imaging who later never develop dementia):

“The scan was developed by scientists in London. The test involves giving a patient exhibiting signs of dementia a small amount of a radioactive substance, which will allow amyloid plaques to show up in a brain scan.

The presence of the plaques in the brain is one of the main signs of Alzheimer’s, although it does not make the disease inevitable, so doctors using the test would be sure of giving a patient the all-clear only if the plaques were absent.

It is the first time doctors have been able to detect the plaques while a patient is alive.”

The desire ‘to catch Alzheimer’s early’ – and the actual pitfalls

A major issue is going to be which people should be put forward for such an imaging technique; there has been intense scrutiny of whether bedside tests can reliably tell the difference between people who have a ‘mild cognitive deficit’ and those who have dementia.

A political drive, almost in total parallel led by the current UK and US governments, to “screen” older people for minor memory changes could potentially be leading to unnecessary investigation and potentially harmful treatment for what is arguably an inevitable consequence of ageing. There are no drugs that prevent the progression of dementia according to human studies, or are effective in patients with mild cognitive impairment, raising concerns that once patients are labelled with mild cognitive deficits as a “pre-disease” for dementia, they may try untested therapies and run the risk of adverse effects.

The idea itself that there is a “pre-disease” stage before the full-blown course of the dementia of Alzheimer type is itself erroneous, if one actually bothers to look at the published neuroscientific evidence. A mild cognitive impairment (“MCI”) is a clinical diagnosis in which deficits in cognitive function are evident but not of sufficient severity to warrant a diagnosis of dementia (Nelson and O’Connor, 2008).

However, the evidence of progression of MCI (mild cognitive impairment) to DAT is currently weak. This has been much to the frustration of some researchers where it had been hoped for years that this could be used to identify DAT at an early stage. It might be attractive to think that MCI is a preclinical form of dementia of Alzheimer Type, but unfortunately the evidence is not there to back this claim up at present: only approximately 5-10% and most people with MCI will not progress to dementia even after ten years of follow-up (Mitchell and Shiri-Feshki, 2009).

It’s the post-diagnosis support anyway…

Either way, there should still be adequate post-diagnosis support, which is a problem which simply won’t go away.

Therefore, this result of a ‘breakthrough’, for one of the more common causes of dementia, has to be sufficiently exciting for the drug companies to have a ‘return on investment’ who have developed them.

However, in a week which has seen increasing scrutiny as to whether pharmaceutical-based approaches have been a waste of dawn, particular interest will be paid as to whether this is in fact yet another “false dawn”.

Other references

Mitchell, A.J., and Shiri-Feshki, M. (2009) Rate of progression of mild cognitive impairment to dementia -meta-analysis of 41 robust inception cohort studies. Acta Psychiatr Scand, 119(4), pp. 252-65.

Nelson, A.P., and O’Connor, M.G. (2008) Mild cognitive impairment: a neuropsychological perspective, CNS Spectr, 13(1), pp. 56-64.

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The G8 Dementia Summit cannot just be about “Pharma-friendly communities”, but must be about people

Shibley Rahman 3 Comments

A ‘cure for dementia’ would be wonderful.

The phrase is, of course, as meaningless as a ‘cure for cancer’, but equally trips off the tongue for corporate fundraising purposes. Like there are many different forms of cancer, like breast, ovary or bone, there are many different forms of dementia, like Alzheimer’s, frontotemporal or HIV.

It’s clear not everyone is going to be a winner from the G8 Dementia Summit promotional package. The write-ups of the dementia research strategy have included ‘the usual suspects’ from “Pharma-friendly communities”, with a token sop to research for wellbeing.

The G8 Dementia Summit is an extremely good way of promoting dementia as a worthy public health issue. Many passionate campaigners will indeed take to the stage to explain, often in very personal terms, why dementia is an incredibly important issue for them. It has become extraordinarily difficult not to know somebody who, in one way or another, is touched by dementia.

The complex nature of dementia has forced policy makers and national governments to invest the financial resources available in three main areas: first, medical research to find a cure for the disease or at least ways to prevent it; second, pharmacological care; and finally, support for caregivers, such as information, training, psychological assistance, etc. Arguably though, none of the three areas, however, have the ‘real’ person at the centre of their interest.

There is also now way that the media can get away with their marginalising of carers for a ‘cure’. Carers face considerable pressures, as they are forced to understand at shotgun notice the biologicial, personal, legal and financial consequences of the dementia. Apart of anything else, many carers, often employed by large private companies, are paid less than a living wage on a ‘zero-hour contract’. Unsurprisingly, how we prioritise the value of care rather than the dividend of a shareholder in a large pharmaceutical company is an important debate to be had.

The cultural stereotype of dementia across various countries is indeed noteworthy. The picture of dementia emerging from these socially-constructed discourses is, at worst, that of a body without a mind, of a hollow shell: that is, a picture in which the dementia “obliterates” the subject, and calls for constant care either by the family members  – informal caregivers – or by formal caregivers, at home or in nursing home facilities. This is a powerful pitch by dementia charities, but stigmatises massively those individuals wishing to lead normal lives with more mild forms of dementia.

The stigma is in fact deeply entrenched. The Merriam-Webster Online Dictionary of 2004 defines dementia first as “mental deterioration of organic or functional origin.” Although a generalization [sic], it seems innocuous and close to what is intended by physicians. However, on further reading almost every dictionary refers to its derivation from Latin, meaning madness or out of one’s mind. This debate has, nonetheless, recently hit a new level with the discussion of whether the word ‘dementia’ should be dropped altogether.

‘Minor or major neurocognitive deficits’ as an alternative term has its supporters and critics.

Norman McNamara, well known campaigner for dementia awareness, has even asked on his Facebook page whether dementia “should come under a mental health banner” (reported here).

Kitwood produced a ‘sea change’ in thinking for placing the individual with dementia at the centre of all discourses about it. Within this social-psychological approach to dementia of the Alzheimer type, Kitwood ́’s concept of personhood emerges. Personhood is defined as ‘a status or standing bestowed upon one human being, by others, in the context of social relationship and social being. It implies recognition, respect and trust’.

Dementia is not an unitary construct. It does not only affect the old. And yet ‘messaging’ of dementia consistently has an unpleasant streak of ageism. According to Richard Titmuss, “Viewed historically, it is difficult to understand why the gradual emergence in Britain of a more balanced age structure should be regarded as a “problem of ageing”.”

Ageist stereotypes in Western culture, from the classical period to the present, have gained strength in a social environment in which ageing is perceived as a problem and portrayed negatively. The general connotations of being old – ill, disabled, with failed memory, senile, sad, lonely, grouchy, sexless, boring, lacking vitality, in decline, unable to learn and unproductive. Stereotypes are powerful, as they spread through cultural productions, media, and policies, hence perpetuating them in the social structure, and empowering collective ideologies by marginalising those belonging to the stereotyped group.

That the G8 dementia summit should have such a naked Pharma bent is of course no big surprise. Sales of the five dementia drugs were just shy of $3 billion in 2007. Donepezil and memantine accounted
for 85% of those sales; tacrine had fallen out of use because of its high adverse effect profile. The memory-boosting drugs, whilst expensive, are generally thought to have very modest effects; and there is no evidence in humans that they slow the rate of progression thus far.

However, the effects of medical labels are always mixed.

Medical labels may operate as instruments of empowerment and social recognition that allow individuals to legitimise their grievances in their own and others’ eyes; they may also operate as instruments of professional expansion, social control, and corporate dominance, serving to pathologise normal functioning, unduly reinforce gender norms.

The danger, observed by some, is that the work of medical researchers has transformed what for years was seen as a rare medical condition into a “major killer” and threat to the wellbeing of predominantly the elderly and their caregivers.

This transformation was critical to the consolidation of a movement born from the grievances of sufferers of a range of cognitive, behavioral and personality impairments and their caretakers, because it gave these impair- ments a biomedical definition, thus creating an “entity” deemed modifiable through the application of biomedical science.

The experience of the USA is interesting. As dementia advocacy grew, so did coincidentally the small government ideology of the Reagan years. (A similar phenomenon is happening here with the UK Coalition administration, though perhaps a ‘small state’ should be more accurately described as an ‘outsourced state’). The Omnibus Budget Reconciliation Act of 1980 was the legislative vehicle for the implementation of this ideology, which reduced social services at the same time that it appeared to respond to the “crisis” and public grievances. The Act gave broad authority to the states to restrict Medicaid program eligibility, reduce the number and type of covered services, and limit payments to hospitals.

These reductions in federal support for health and social services occurred at a time when states and cities were experiencing the combined effects of a lagging economy and of various spending limitations imposed by the passage of tax-limiting measures such as Proposition 13 in California and Proposition 2 1⁄2 in Massachusetts.

Yet another element leading to the triumph of “cure” over “care” was a largely idealised notion of “nuclear family” family functions, which grained ground during this time of political and cultural conservatism, and legitimised an inequitable societal workload falling on women in the provision of long-term care.

Clearly, caregiving, a resource-intensive activity falling predominately on women, is neither “budgetable” nor appreciated at the policy level. So again, rather paradoxically, not only did the heart-rending testimony of caregivers to Congressional committees advocating for more support fail to lead to more formal services and relief of women’s workload, it also legitimised the biomedical framework that deviates public support away from caregivers, as it feeds the hope for effective treatments or a cure for dementia that presumably will derail the “explosive” future costs of caring.

Ironically, here in the UK, the website of the “Dementia Advocacy Network” gets taken down at the end of next month. It is in fact the last week of its hardworking manager, Jan Kendall. This Network was invaluable in offering non-statutory guidance for advocacy, in keeping with statement 9 of the recently published NICE quality standard. This statement on independent advocacy.

DAN

Jan Kendall’s experience is sadly not unique. There has been a starvation of funds as many entities in the third sector have found it difficult to cope. The situation in the charity sector is remarkably similar to how City firms have experienced maintained revenues, while high street law firms have been forced to shut down.

The narrative from “Pharma-friendly communities” in the media threatens to drown out what is actually happening on the ground. It is recently reported that budget cuts forced a record 220,000 dementia sufferers to turn to hospital A&E units for help last year.

There is, of course, nothing to stop Big Pharma or large dementia charities to act as good ‘corporate citizens’ , in keeping with the views of Professor Michael Porter at Harvard Business School, in helping to fund frontline care.

But the danger is that this ‘drive for a cure’ represents yet another attack on the running of a universal healthcare system, which should be in principle funded through a fair and equitable general taxation.

Julian Tudor-Hart unsurprisingly puts it perfectly.

“Volume, costs and content of medical care depend on demand, which depends on professional and public expectations. The UK National Health Service (NHS) removed price barriers to access, and depressed expectations became an important factor in cost control. In USA, professional control of care business inflated expectations, and consequent costs. Managed care in the NHS failed to rationalise care because managers seem even less trustworthy than clinicians as arbiters of rational expectations in contexts of permanent underfunding. Development of rational expectations depends on restored trust, mutual and managerial respect for the expertise of both clinicians and patients, and transcendence of the provider-consumer model for value production in medical care.”

This is, contrast, is EXACTLY what person-centred care should be aiming to achieve: allowing people to live well with dementia. The ability of drugs to help people to live well with dementia currently is relatively poor. But Beth’s experience should indeed be about inspiring people who care about dementia. Thanks also enormously to the Department of Health for their efforts in this direction.

Enormous thanks to Dr John Rumbold, Dr Jonathon Tomlinson and Prof Julia Simard for indirect help with this article.

Living well with dementia: diet not drugs?

Shibley Rahman 1 Comment

Mediterranean diet

There is no cure for dementia currently. The available treatment strategies offer mainly symptomatic benefits. Thus, strategies to prevent or delay onset of dementia by changes in lifestyle factors, such as diet, are therefore important, given finite resources. There is no doubt it’d be wonderful if, after many many years of trying, there might be a breakthrough.

But physicians and politicians have a responsibility to the general public to be honest about what is genuinely achievable. It’s in the interests of charities and research groups which depend on income for their research to raise money for a cure; or in the interests of those research groups wishing to raise money for research which appears linked to that somehow. It’s in the interest of Big Pharma-ceutical companies to raise money for their research funds; and they have a legal duty to their shareholders too. The public appreciate a truthful debate about what might work; and where a lot of monies would in fact would be better spent elsewhere.

It’s certainly low hanging fruit for politicians to support this worthy cause.

However, the scant attention to living well with dementia in many statements, in contrast to drug treatments, is very telling. The Department of Health will, however, be livestreaming the #G8dementia summit proceedings later this week. Details are here.

Not all dementia occurs in the elderly. Nonetheless, it is possible that health problems related to aging (including dementia of the Alzheimer type) are projected to add to the high clinical, social, and economic burden of caring for persons with dementia.

The Mediterranean diet has been associated with reduced risk for a wide range of age-related conditions such as stroke, type 2 diabetes, cardiovascular disease, and all-cause mortality. The traditional Mediterranean diet refers to a multinutrient dietary profile characterized by high intake of fruits, vegetables, cereals, and legumes; low consumption of saturated fats with olive oil as the main source of fat; moderate consumption of fish; low to moderate intake of dairy products (in the form of yogurt and cheese); low consumption of red meat and meat products; and moderate amount of alcohol (especially wine) usually consumed during meals.

Recently, a number of peer-reviewed pieces in the reliable academic literature have presented evidence for an association between a Mediterranean-type diet and decreased risk of dementia. Findings from prospective studies suggest that greater adherence to Mediterranean diet may be associated with slower cognitive decline and reduced risk of Alzheimer disease. In the light of these findings, it has been suggested that improving adherence to the Mediterranean diet may delay or prevent the onset of dementia.

A really helpful review was published by Lourida and colleagues earlier this year in the “Epidemiology” journal (Jul;24(4):479-89). Twelve eligible papers (11 observational studies and one randomized controlled trial) were identified, describing seven unique cohorts.

Despite methodological heterogeneity and limited statistical power in some studies, there was a reasonably consistent pattern of associations. Higher adherence to Mediterranean diet was associated with better cognitive function, lower rates of cognitive decline, and reduced risk of Alzheimer disease in nine out of 12 studies, whereas results for mild cognitive impairment were inconsistent.

Published studies suggest that greater adherence to Mediterranean diet is associated with slower cognitive decline and lower risk of developing Alzheimer disease. Further studies would be useful to clarify the association with mild cognitive impairment and vascular dementia. Long-term randomised controlled trials promoting a Mediterranean diet may help establish whether improved adherence helps to prevent or delay the onset of Alzheimer disease and dementia.

Only today, leading doctors warned the Government the battle against dementia should focus on the benefits of a Mediterranean diet rather than ‘dubious’ drugs. In an open letter to the Health Secretary, they said persuading people to eat fresh fruit and vegetables, nuts, fish and olive oil was ‘possibly the best strategy currently available’ for preventing Alzheimer’s and other memory-robbing diseases.

The letter’s signatories include Prof Clare Gerada, the former chairman of the Royal College of General Practitioners, and Dr David Haslam, chairman of the National Obesity Forum.

It reads:

‘We hope this crisis can be seen as an opportunity towards a real policy change, namely towards a Mediterranean diet, rather than towards the dubious benefits of most drugs.’

It goes on to say the evidence ‘strongly suggests’ that improvements to lifestyle will have a ‘far greater effect’ on the rising tide of dementia than drugs.

The call comes as dementia experts from the G8 countries prepare to travel to London for a summit hosted by the Prime Minister.

Dr Simon Poole, the GP who organised the letter, said: ‘It is all about looking at what pharmaceutical companies can do, which is actually not very much.

‘They talk up their medicine and then it is very often a damp squib. We want some sort of focus on prevention. Educating all generations, including our children, in the importance of a good diet in maintaining health in old age is a project which will take years, but is absolutely essential.’

‘We are calling upon policymakers to not only support the care and treatment of those who are already suffering from dementia, but to make significant investments in work which will see benefits beyond the period of one or two parliaments.’

There has also been a focus on individual components of the Mediterranean diet, such as [omega]-3 fatty acids or olive oil as the main source of monounsaturated fats. Although the advantages of Mediterranean diet are relevant for non-Mediterranean populations, it is often argued that studies are not always comparable because there are substantial differences in dietary composition among countries.

A more detailed examination reveals this is perhaps especially true for fatty acids. Although olive oil is the hallmark of Mediterranean diet, differences in the origin of monounsaturated fats or cooking style (eg, baked vs. fried) could partly explain these inconsistencies. Studies comparing types of olive oil concluded that compared with refined oil, virgin olive oil (rich in phenolic content) has additional anti-inflammatory and antioxidant properties beneficial to cellular function and cardiovascular health.

The Mediterranean diet may exert its effects on cognitive health through multiple biological mechanisms. Relationships with reduced risk of coronary heart disease, hypertension, diabetes, dyslipidemia, and metabolic syndrome have been observed, and these conditions have also been associated with mild cognitive impairment, vascular dementia (a dementia associated with general factors affecting the cardiovascular system such as smoking, cholesterol, diet, family history), or disease of the Alzheimer type.

Sticking to this Meditteranean diet may also facilitate metabolic control because it has been related to improved insulin sensitivity and glucose metabolism. Insulin is a chemical acting in the body which can affect our metabolism – it is an important “hormone” for us.

Furthermore, “oxidative stress” increases with age and results in “oxidative damage”—a state often observed in the brain of patients with Alzheimer disease. Typical components of the Mediterranean diet (namely fruits, vegetables, wine, and virgin olive oil) are rich in antioxidants such as vitamin C and E, carotenoids, and flavonoids. Decreased oxidative stress found in people adhering to a Mediterranean-type diet could partially explain their lowered risk for dementia.

And there’s a plausible biological mechanism for all this. Brain cells (neurone) are protected against oxidative stress by specialist chemicals, called “neurotrophins” (basic proteins) such as the brain-derived neurotrophic factor. There is some evidence that Mediterranean diet may increase plasma brain-derived neurotrophic factor concentrations. Inflammatory processes have also been suggested for Alzheimer pathogenesis. Higher concentrations of C-reactive protein, a nonspecific marker of inflammation, have been associated with increased risk for cognitive decline, Alzheimer disease, and vascular dementia, whereas better adherence to Mediterranean diet has been associated with lower levels of C-reactive protein.

Access to medicine has become a really important issue in the NHS. Already we are getting stories of rationing in the NHS emerging during the period of this Government (such as varicose veins stripping), so it is not particularly surprising if drugs which do have modest effect on memory for dementia are not a top priority. Encouraging people to learn about diet and how this might prevent thinking problems is therefore a worthy aim, as it might actually work better than many of the drugs ‘on offer’.  Senior doctors have advised this approach in fact.

Just because it’s not coming from Big Pharma with their massive marketing budgets doesn’t mean it’s a dead duck.

Related articles

The #G8Dementia Summit – a curious lack of a person-centred approach in the research strategy

Shibley Rahman 3 Comments

Trade fair for blog

David Cameron should be given credit for making ‘dementia’ the topic for discussion of the G8 on 11th December 2013. But the event runs the risk of being a trade fair for the pharmaceutical industry, becoming increasingly desperate to prove their worth in dementia and society.

However, it is widely acknowledged that cholinesterase inhibitors, drugs that boost levels of acetylcholine in the brain to improve attention and memory, have a modest effect if that in the majority of patients with early dementia of the Alzheimer type (‘dementia of the Alzheimer type’). There is no robust evidence that they slow down disease progression in humans from human studies of patients.

Many senior academic experts feel conversely that there has been insufficient attention put into interventions that actually do help people to live well with DAT. Such interventions include improving the design of the home, design of the built environment (including signage and pavements), non-statutory advocacy, dementia-friendly communities, assistive technology and ambient living innovations.

On Wednesday 4th December 2013, a ‘research summit’ was held for the press for “research into dementia”. The main focus of this research summit was how can one best predict who will get dementia or when, do we even know what causes dementia yet, what “cures” are there in the pipeline, what can be done to prevent dementia, what obstacles are pharmacological researchers facing, does Pharma have sufficient resources, and what needs to be done to make the Dementia Summit a success.

The focus of this ‘summit’ into ‘research into dementia’ was not living well with dementia, which is a gobsmacking tragedy for all those involved in promoting living well with dementia.

What is overwhelmingly absent is a ‘person centred approach’ which has been a major force for good in contemporary dementia care in England.

The panel members, according to the brief, were: Dr Doug Brown, Director of Research and Development, Alzheimer’s Society; Prof Nick Fox, Professor of Neurology, MRC Senior Clinical Fellow, Institute of Neurology, University College London; Prof Simon Lovestone, Professor of Old Age Psychiatry, Director of NIHR Biomedical Research Centre for Mental Health at the South London and Maudsley NHS Trust and Institute of Psychiatry, King’s College London and Lead for the Translational Research Collaboration in Dementia (a network of 6 centres established by the NIHR); Prof Peter Passmore, Professor of Old Age Psychiatry, Queen’s College Belfast and Lead for Dementia for The British Geriatrics Society; and Dr Eric Karran, Director of Research, Alzheimer’s Research UK.

To show how little there was on wellbeing, and discussing innovative ways to allow people to live well with dementia, here’s the official write up from the BMJ this week:

“Nick Fox, professor of neurology and a Medical Research Council senior clinical fellow at the Institute of Neurology at University College London, said, “We should be asking the G8 collectively to double the research spending on dementia within five years.

“And I think there is a lovely equitable way of looking at this. We ask the G8 countries to commit 1% of their dementia costs to add another doubling of research spending within 10 years.”

Brown said the aims of the research were to enable more accurate and timely diagnosis of dementia; to create disease modifying treatment to try to stop, slow, or reverse the condition; and to find drugs to treat the symptoms. Most importantly, he said, researchers needed to understand how dementia developed to enable the risk to be reduced and onset of dementia to be prevented or at the very least delayed. “If we could delay the onset by five years we could probably cut the numbers of [people with] dementia in half,” he said.

Fox said that past trials of treatments had concentrated on people with symptoms of the disease, which was “like trialling chemotherapy when people are already in a hospice.” Now, he said, treatments were beginning to be tested in people who were at higher risk of dementia because they had a family history or other genetic risk factors or because scans had shown early features of the disease.

Scans and other techniques could then be used to track the effects of treatment before symptoms appeared. “Only if we can identify people where we can see whether our therapies are having an effect will we ever make progress,” Fox said.

Peter Passmore, professor of old age psychiatry at Queen’s College Belfast and the British Geriatrics Society’s lead on dementia, said that as more was known about the mechanism of dementia, researchers were looking at drugs licensed for other conditions that might impinge on those mechanisms. “That’s cheaper drug development: those drugs are off patent,” he said.”

Many thanks to @sam4wong for sharing this with us on Twitter this morning.

Sadly, this representation of research for #G8dementia has taken on more of an appearance of a corporate international trade fair, which is a crying shame. This is, ironically, in the week that the World Trade Organization has apparently agreed its first-ever global deal aimed at boosting commerce.

A trade fair (trade show, trade exhibition or expo) is an exhibition organised so that companies in a specific industry can showcase and demonstrate their latest products, service, study activities of rivals and examine recent market trends and opportunities. In contrast to consumer fairs, only some trade fairs are open to the public, while others can only be attended by company representatives (members of the trade, e.g. professionals) and members of the press, therefore trade shows are classified as either “Public” or “Trade Only”. However, the G8 next week would be at considerable risk of being hijacked by market forces, if it were not for the valiant efforts of the Department of Health and people who have devoted their lives to raising dementia awareness too. Trade fairs are helpful for marketing of products to a wider audience.

James Murray-White (@sky_larking) is a film-maker, and campaigns perennially for raising dementia awareness. James announced yesterday that he was proud to be part of a central network of dementia ‘activists’ on Twitter, but had just reported on the same media network that he had recently been refused ‘press accreditation’ for #G8dementia.

Earlier this year, filmmakers and scientists came together at this event to increase the public understanding of dementia. This event comprised series of short films about dementia, curated by Murray-White, will precede a discussion with researchers from the University of Bristol and other institutions supported by @AlzheimersBRACE, a local charity that funds research into Alzheimer’s disease and other forms of dementia. Panel speakers included: Professor Seth Love (Professor of Neuropathology); Laura Palmer (South West Dementia Brain Bank Manager); James Murray-White (filmmaker).

However, all is not lost, by any means.  Beth Britton (@BethyB1886) will be participating in a short film for #G8dementia. Prof Alistair Burns (@ABurns1907), the Clinical Lead for Dementia in England, has written of Britton:

“Beth Britton has been a breath of fresh air in the discussions and debates around dementia. She brings a clarity of thought and originality of ideas which I have always found very refreshing and helpful when considerations and discussions of the importance of people with dementia and their carers are concerned. She has a unique writing style and a gifted ability to convey ideas and experiences”

Beth is one of the U.K.’s leading campaigners on dementia. Her experience of supporting her father, who was living with dementia, and her professional background, give her unparalleled insight into effective ways of campaigning for change, it is widely felt.

There are people who are simply interested in individuals with people  – the person not the drug. For example, Lucy Jane Masters (@lucyjmasters) is a dementia nurse specialist, advocating for change, an educator, and primarily passionate about that person with dementia and those who care for him or her.

Alistair has for long time emphasised the importance of “a timely diagnosis”, rather than an “early diagnosis”. This is very much in keeping with the notion that the potential diagnosis should be offered at a time personally appropriate to any particular individual. Alistair also believes, in his rôle as part of NHS England, that there should be a reasonable level of “post-diagnosis support”. Academics generally agree that the tenure of Alistair as the National Lead for Dementia in England has been a very successful experience for all involved.

There are few people as inspirational too as Norman McNamara, who has campaigned tirelessly to dissolve the stigma which can surround dementia. He can be very easily found on Twitter for example (@NormanMcNamara). McNamara has written poignantly about his own personal experiences of ‘living with dementia’.

Sally (@nursemaiden) was a senior nurse, but likewise now promotes heavily wellbeing in dementia, with her father with dementia of the Alzheimer type having passed away on 1st September 2012.

And it truly is an international ‘effort': Kate Swaffer (@KateSwaffer) in Australia – who has just met up with Gill Phillips who advocates ‘paths to personalisation’, has written brilliantly about her experiences of the dementia diagnosis.

Indeed, it would not be hyperbolic to say that many people have given up much free time into the world of the dementias, as a vocation. Lee (@dragonmisery) has produced an incredible information provision website for carers of people with dementia, and this has advanced the policy plank promoting choice and control in wellbeing.

Twitter has been particularly successful at giving people a voice at last. Charmaine Hardy (@charbhardy) is one of the most prominent members of this very close community. Her profile reveals that her husband, whom she adores, has a rare dementia known as primary progressive aphasia. Anyone following Charmaine knows exactly the emotional intensity of someone caring for somebody with dementia.

Likewise, Thomas Whitelaw (@TommyNTour) has literally been ‘on tour’ talking with amazing authentic emotion, affectionately, about his mother, Joan Whitelaw, who had been living with dementia.

So why such a focus on pharmacology?

Why so little on ‘person centred care’?

This glaring omission of person centred care in #G8 dementia apart from representations below is utterly embarrassing and humilating for the thousands of researchers and practitioners who work in this area. @MrDarrenGormley‘s award-winning blog is a most useful introduction to this area.

And, although deeply enmeshed in the English health policy which has sometimes been far from controversy, the efforts of the Department of Health itself have been most impressive.

Anna Hepburn (@AnnaHepburnDH) is Digital Communications Manager for Social Care at the Department of Health. Anna is well known to be genuinely interested in the views of people living with dementia, and those closest to them.

Anna remarked recently,

“When people with dementia and their partners were invited to the Department of Health recently, there was one simple statement that stuck in my mind: “We are still people”. It came as a bit of a shock coming from one of the articulate and funny people gathered round the table. But it says it all about the misconceptions and stigma surrounding dementia.”

Anna Hepburn continued,

“On 18 November, I had the privilege of meeting more people with dementia, as well as current and former carers of people with dementia, who came to London to make short films to show at the G8 dementia summit. This is so we can bring their voices – and the reality of dementia – into the room on 11 December.”

But as a result of the research summit and other efforts from the media and select researchers, the headlines have been rather sensational and sadly all too predictable, viz:

“Unprecedented breakthrough in the hunt for a dementia drug within ‘five years'” (Independent)

“G8 ministers warned to prepare for global dementia ‘time bomb’” (Times)

“Monthly injection to prevent Alzheimer’s in five years” (Telegraph)

“Jab to slow Alzheimer’s ‘is just five years away': Monthly treatment could be given a decade before symptoms” (Daily Mail)

“Dementia cases ‘set to treble worldwide’ by 2050” (BBC)

The last one has been the most difficult for real experts  in the research community with real knowledge of the problems facing international research.

On the other hand, Mr Jeremy Hughes, chief executive of the UK’s Alzheimer’s Society, according to that final BBC report cited above, said: “Dementia is fast becoming the biggest health and social care challenge of this generation.”

“We must tackle dementia now, for those currently living with the condition across the world and for those millions who will develop dementia in the future.”

There has been much media interest in improving diagnosis rates in England, driven more by the dementia charities than public health physicians or GPs.  Whilst undoubtedly a ‘cure’ for dementia would be wonderful, it is rarely reported that dementia rates are in fact considered to be dropping.  Medical doctors such as Dr Peter Gordon (@PeterDLROW; a NHS Consultant Psychiatrist) and Dr Martin Brunet (@DocMartin68; a NHS General Practitioner) have been invaluable as “thought leaders” in forging ahead with an evidence-based approach to this complex issue, cutting through the media garb and spin (and promotional copy).

Very recently in the prestigious New England Journal of Medicine, it was reported that, “Although demographics will drive an increase in the number of dementia cases, recent reports — generally based on population-based community studies or survey data — point to declining age-specific prevalence or incidence rates among people born later in the first half of the 20th century”

You can follow live digital coverage of the G8 dementia summit on the Dementia Challenge site on 11 December 2013. Well done to all those involved, particularly the grassroots campaigners, Anna Hepburn, and the Department of Health!

Activities and networks

Shibley Rahman 0 Comments

One of the most challenging aspects of providing care for someone with a dementing illness is to develop daily routines and activities that are interesting, meaningful, do-able, and valued by the person with the disease. Making sure there is a mix of activities to meet social, physical, mental, and spiritual needs for each individual is a complex and ever-changing task. Also, social networks are becoming increasingly online, and this is an important consideration for care. According to Shirley Ayres in her excellent “provocation paper” for the Nominet Trust (2013), social networks can be widened and enhanced by web-based tools and technology. The growth of online personal support networks strengthens the informal networks that already exist within communities. This paper has turned out to be a seminal contribution.

Studies related to older people with (or without) dementia have not been able to reach a consensus on the types and intensity of the exercise, nor the frequency and duration of the intervention to be most effective and efficient (Thorn and Clare, 2011). Heyn and colleagues carried out meta-analysis of exercise in dementia and reported data on thirty trials of exercise (Heyn et al., 2004). The authors reported on trials that included strength, cardiovascular or flexibility regimes; and analysed for functional, cognitive or behavioural outcomes. A significant positive effect of exercise on behavioural outcomes was reported. However these trials do not provide a full picture of the effectiveness of exercise on BPSD for a number of reasons. There was considerable heterogeneity in terms of the interventions, and exercise was often combined with other behavioural interventions. Thus, it is difficult to isolate the impact that exercise has had on behavioural outcomes. Some regimes were quite complex and require a high degree of physical fitness that would preclude many older adults with complex physical problems and moderate or profound dementia from performing them. Moreover, they were potentially unsustainable without the support of trained therapists. Finally, the relatively high cost of delivery and specialist input required may prevent the interventions being used more widely. Most trials included in the analysis were relatively small, with only two of the eight studies that reported effects on behaviours having samples in excess of 100 participants.

Forbes and colleagues (Forbes et al., 2008), on behalf of the Cochrane Collaboration, found that four trials met their inclusion criteria. However, only two trials were included in the analyses because the required data from the other two trials were not made available. Only one meta-analysis was conducted. The results from this review suggest that there is insufficient evidence of the effectiveness of physical activity programs in managing or improving cognition, function, behaviour, depression, and mortality in people with dementia. Few trials have examined these important outcomes. In addition, family caregiver outcomes and use of health care services were not reported in any of the included trials.

Some earlier studies had suggested that physical exercise may be beneficial in dementia. Physical activity and regular exercise training may slow down cognitive decline (Kramer et al., 2006), and it has positive effects on cognition among those with cognitive decline (Heyn et al., 2004). Physical exercise appears to alleviate depression and reduces behavioural symptoms in dementia patients (Teri et al., 2003).

physical activity

“Social activity” – specifically activities that can broadly be seen as participation in society and between the generations – has been an important thrust of dementia wellbeing policy for some time. The World Health Organization (WHO, 2002) has defined active ageing as having not only physical and psychological dimensions but also as the capacity to participate in society. Social and cultural activities have also been shown to be beneficial in terms of wellbeing, functioning and survival (Glass et al., 1999). What is clear is that successful ageing and wellbeing in dementia involve a complex interplay between personal and social factors – however a common feature is “activity”, whether that is physical, cognitive or social.

A positive effect of physical activities on survival has long been recognised (Paffenberger et al., 1993); more recently, a similar effect was also reported for social and productive activities (Glass et al., 1999). Social disengagement has been suggested as a possible risk factor for cognitive decline in elderly persons (Bassuk et al.,1999). In a Swedish community-based study, the “Kungsholmen Project”, a rich social network showed a protective effect against dementia (Fratiglioni et al., 2000).

Some things to read

Ayres, S. for the Nominet Trust (2013) Can online innovations enhance social care? http://www.nominettrust.org.uk/sites/default/files/Enhancing%20social%20care_PP_0113.pdf

Bassuk, S.S., Glass, T.A., and Berkman, L.F. (1989) Social disengagement and incident cognitive decline in community-dwelling elderly persons, Ann Intern Med, 131, pp.165–73.

Fratiglioni, L, Wang, H.X., Ericsson, K., Maytan, M., and Winblad, B. (2000) The influence of social network on the occurrence of dementia: a community-based longitudinal study, Lancet, 355, pp. 1315–19.

Glass, T.A., de Leon, C.M., Marottoli, R.A., and Berkman, L.F. (1999) Population-based study of social and productive activities as predictors of survival amongst elderly Americans, BMJ, 319, pp. 478-83.

Heyn P, Abreu BC, and Ottenbacher KJ. (2004) The effects of exercise training on elderly persons with cognitive impairment and dementia: a meta-analysis, Arch Phys Med Rehabil, 85, pp. 1694-1704.

Kramer, A.F., Erickson, K.I., and Colcombe, S.J. (2006) Exercise, cognition, and aging brain, J Appl Physiol, 101:1237-1242.

Paffenbarger, R.S. Jr., Hyde, R.T., Wing, A.L., Lee, I.M., Jung, D.L., and Kampert, J.B. (1993) The association of changes in physical-activity level and other lifestyle characteristics with mortality among men, N Engl J Med, 328, pp. 538–45.

Teri, L., Gibbons, L.E., McCurry, S.M., Logsdon, R.G., Buchner, D.M., Barlow, W.E., Kukull, W.A., LaCroix, A.Z., McCormick, W., and Larson, E.B. (2003) Exercise plus behavioural management in patients with Alzheimer disease: A randomized controlled trial, JAMA, 290, pp. 20015-2022.

Thom JM, and Clare L. (2011) Rationale for combined exercise and cognition-focused interventions to improve functional independence in people with dementia, Gerontology, 57, pp. 265-275.

WHO (World Health Organization) (2002) Active Ageing: A Policy Framework. Geneva: WHO.

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Living well with specific types of dementia: a cognitive neurology perspective

Shibley Rahman 7 Comments

Dementia image

Dementia is a very complex construct, embracing a number of different possible diagnoses, with different time courses. There is a common perception that ‘dementia’ is a single disorder, further perpetuated by most of the media, but this is far from true, and indeed a critical rôle of the cognitive neurologist might be try to identify what particular type of dementia an individual might be living with. This might best inform an approach to be taken by all specialties in helping that individual, and specific problems might be, for example, in wayfinding or social interactions at an early stage.

There are many different types of dementia, and they all tend to affect various bits of the brain as the disease progresses in a certain order. Whilst the patterns of progression are not identical, it can be observed that certain issues are more likely to met in some forms of dementia rather than others. For example, an individual with dementia of the Alzheimer type (DAT) is likely to have difficulty with spatial navigation or wayfinding earlier on, as the part of the brain affected in that type of dementia earlier one tends to be the areas around the hippocampus in the temporal lobe part of the human brain. Conversely, in behavioural variant frontotemporal dementia (bvFTD), individuals can be referred to health services because of a subtle change in personality and behaviour, with memory for day-to-day events relatively intact.

Any analysis of ‘living well in dementia’ has to acknowledge that dementia is a “heterogeneous” condition, and a specialist view of dementia will tend to consider specific issues which may be more relevant in the activities of daily living in any individual with dementia. This focused approach is likely to be a constructive one, to help society enable individuals with dementia with their distinct issues. If these issues can be addressed in a way that appreciates the individual as a person, rather than ‘medicalising’ the patient, the wellbeing of immediates (e.g. family or friends) is likely to be better too.

Dementia of Alzheimer type

Dementia of Alzheimer type is the most common cause of dementia and a growing health problem globally, affecting 20% of the population over 80 years of age (Ferri et al., 2005).

Pathology

Currently, the definite diagnosis of DAT can only be made through autopsy to find the pathological hallmarks of the disease, microscopic amyloid plaques and neurofibrillary tangles. The development of biomarkers that can reliably indicate presence of the disease at the earliest possible stage is therefore an important public health goal. Macroscopically, DAT is associated with progressive brain tissue loss (Braak and Braak, 1998), which MRI can non-invasively visualise to some extent in-vivo (Thompson et al., 2007). Unsurprisingly, MRI has attracted considerable interest as a tool to identify DAT biomarkers.

Histological studies have shown that the hippocampus is particularly vulnerable to DAT pathology and already considerably damaged at the time clinical symptoms first appear (Braak and Braak, 1998).

Spatial cognition

The “cognitive map theory” proposes that the hippocampus of rats and other animals represents their environments, locations within those environments, and their contents, thus providing the basis for spatial memory and flexible navigation. When it comes to humans, the theory suggests a broader function for the hippocampus, based at least in part on lateralisation of function (Burgess, Maguire and O’Keefe, 2002). The cognitive map theory posits that the hippocampus specifically supports allocentric processing of space in contrast to other brain regions, such as the parietal neocortex, which support egocentric processing (O’Keefe and Nadel, 1978).

Structural MRI scans of the brains of humans with extensive navigation experience, licensed London taxi drivers, were analysed and compared with those of control subjects who did not drive taxis. The posterior hippocampi of taxi drivers were significantly larger relative to those of control subjects. A more anterior hippocampal region was larger in control subjects than in taxi drivers. Hippocampal volume correlated with the amount of time spent as a taxi driver (positively in the posterior and negatively in the anterior hippocampus). These data are in accordance with the idea that the posterior hippocampus stores a spatial representation of the environment and can expand regionally to accommodate elaboration of this representation in people with a high dependence on navigational skills. It seems that there is a capacity for local plastic change in the structure of the healthy adult human brain in response to environmental demands.

Wayfinding

Problems in navigation could even be a good way to diagnose early dementia of Alzheimer type (“DAT”), in future. Virtual reality (“VR”) allows naturalistic evaluation of spatial cognition disorders associated with DAT. These measures seem to be well correlated to daily difficulties of people, thus providing specific measures of cognitive deficits and their functional impact. Thus, VR would be a relevant tool for the early screening of dementia and the differential diagnosis of DAT (Déjos et al., 2011).

While there is abundant evidence for spatial learning and memory decrements in patients with unilateral hippocampal lesions, remarkably little research has been done on spatial memory and learning in patients with DAT, in which relatively selective bilateral hippocampal atrophy is consistently reported in the early stages of the disease (de Pol, 2006). Only a few studies have examined static object-location memory tasks in DAT patients, demonstrating impaired performance compared to controls (Bucks and Willison, 1997; Kessels et al., 2010). Using a real-world wayfinding test, Monacelli and colleagues (Monacelli et al., 2003) investigated a group of DAT patients and demonstrated impaired spatial navigation and spatial orientation in the DAT group, possibly due to an underlying deficit in linking landmark information to route knowledge. Similar findings have also been reported using virtual maze-learning paradigms in AD patients (Cushman, Stein and Duffy, 2008; Kalova et al., 2005).

Current pedestrian navigation systems predominantly use distance-to-turn information and directional information to enable a user to navigate. However, Cherrier and colleagues (Cherrier, Mendez and Perryman, 2001) showed that dementia patients performed better on recognition of landmarks compared with recognition and recall of spatial layout.  Furthermore, relatively few studies have examined the workplaces of staff compared to those that address outcomes for patients and their families. One theme that has been receiving increasing attention over the last few years in the literature about healing environments is wayfinding.

In addition to a complex floor plan, there are other elements that contribute to poor wayfinding and inadequate or conflicting cues such as colours and lighting (Brown, Wright and Brown, 1997). In addition to these elements, clear and understandable wayfinding and maps are fundamental to becoming oriented. However, maps should be oriented so that the top signifies the direction of movement for ease of use (Ulrich et al., 1994). Moreover, the number of signs available has a significant effect on wayfinding along many different measures including travel time, the frequencies of hesitations, the number of times directions were asked, and the reported level of stress. These results suggest that directional signs should be placed at or before every major intersection, at major destinations, and where a single environmental cue or a series of such cues (for instance, a change in flooring material) conveys the message that the individual is moving from one area into another. If there are no key decision points along a route, signs should be placed approximately every 4.6-7.6 m (Ulrich et al., 1994).

Earlier studies reviewed by Day and Calkins (2002) found that much of the orientation work revolved around “signage”, and indentified that personalised and/or unique signage assisted residents in locating desired destinations. Passini and colleagues (Passini et al., 2000) studied newly admitted residents with dementia, and noted that learning new routes was a slow process. Residents who could not identify paths to desired locations exhibited anxiety, confusion, mutism and even panic. They also noted that some residents perceived patterns on the floor as a barrier. They conclude that “capacity of decision-making is reduced to decisions based on immediate and visually accessible information” whether that information was signs, landmarks, or direct visibility of the desired location. They also noted that the typical location of signs is often not seen by residents whose visual field is low to the ground.

Rule, Milke and Dobbs (1991) also found that features such as many similar doorways along corridors, lack of windows to the outside and signage resulted in poorer orientation. McGilton, Rivera and Dawson (2003) conducted a randomised control trial to ascertain the effects of using a locational map and training techniques on the ability of residents to locate distance locations (a dining room on a different floor). While residents in the treatment group showed significant effect within one week of starting the trial, the effect was not sustained three months later.

Driving and DAT

Safe automobile driving requires a driver to perform multiple competing tasks and attend to a host of objects and ongoing events, while simultaneously monitoring traffic with central and peripheral vision to avoid roadway hazards. Impairments of visual acuity and visual fields increase crashes and traffic violations (Burg, 1971). However, drivers with certain neurological conditions may potentially fail to perceive critical roadside targets and dangers even in the absence of a measurable field defect on standard perimetry or diminished visual acuity (Owsley and McGwin, 1999).

Former Urbanites Find Jersey Driving Intimidating

DAT affects processing of visual sensory cues and may produce attentional decline and agnosia (for a review, see Hodges, 2011). These deficits can impair drivers’ processing of visual information such as roadway landmarks and traffic signs that provide key information about a driver’s route, upcoming road hazards, and safety regulations. Uc and colleagues (Uc et al., 2005) studied 33 drivers with probable DAT of mild severity and 137 neurologically normal older adults using a battery of visual and cognitive tests and were asked to report detection of specific landmarks and traffic signs along a segment of an experimental drive. The drivers with mild DAT identified significantly fewer landmarks and traffic signs and made more at-fault safety errors during the task than control subjects.

“The social animal”

“The Social Animal: The Hidden Sources of Love, Character, and Achievement” is a highly celebrated non-fiction book by American journalist David Brooks (Brooks, 2012), who is otherwise best known for his career with The New York Times. The book discusses what drives individual behaviour and decision-making.  Brooks asserts that people’s subconscious minds largely determine who they are and how they behave. He argues that deep internal emotions, the “mental sensations that happen to us”, establish the outward mindset that makes decisions such as career choices. Brooks describes the human brain as dependent on what he calls “scouts” running through a deeply complex neuronal network.

Ultimately, Brooks depicts human beings as driven by the universal feelings of loneliness and the need to belong—what he labels “the urge to merge.” He describes people going through “the loneliness loop” of internal isolation, engagement, and then isolation again. He states that people feel the continual need to be understood by others.

We are, above all, “social animals”, and this is of fundamental importance for wellbeing. For example, Prof. Mario Mendez and Prof. Facundo Manes write recently (Mendez and Manes, 2011), and the authors reviewing this important recent collection of papers on social cognition discuss social cognition dysfunction in a number of different clinical situations, and their potential to give rise to problems in social interactions, immoral or even corrupt behaviour.

Response to stress and resilience

“Resilience” refers to a person’s ability to adapt successfully to acute stress, trauma or more chronic forms of adversity. A resilient individual has thus been tested by adversity (Rutter, 2006) and continues to demonstrate adaptive psychological and physiological stress responses, or `psychobiological allostasis’ (McEwen, 2003; Charney, 2004).

The study of resilience, or stress-resistance, originated in the 1970s with a group of researchers who directed their attention to the investigation of children capable of progressing through normal development despite exposure to significant adversity (Masten, 2001). For many years, research focused on identifying the psychosocial determinants of stress resistance, such as positive emotions, the capacity for self-regulation, social competence with peers and a close bond with a primary caregiver, among other factors (Masten, 1998; Rutter, 1985).

The importance of resilience in policy in living well in dementia, and will be considered further in the final chapter, chapter 18.

Contextual learning

Context-dependence effects are pervasive in everyday cognition. When we perceive objects and colours, we always perceive these among other objects and colours. We listen and speak within other word streams, and every atom of meaning emerges from a background of meanings. Acting appropriately in social interactions requires the interpretation of explicit and implicit contextual clues that orient our responses toward being polite, to make a joke or point out an irony, to say or not say something. Cognitive science and neuroscience research have evidenced context-dependence effects in similar domains of visual perception, emotion, language,  and social cognition in both normal and neuropsychiatric conditions.

Context is important, as shown by the Ebbinghaus illusion which depicts two identical central circles, surrounded by rings of circles. Despite the fact that they are the same size, one circle is perceived as small and the other as big. The contextual information available (the surrounding circles) creates the perception that the center circles are different sizes. This is shown below.

Contextual effects are present at every level, from basic perception to social interaction. This means that we do not perceive objects or process cognitive events in an abstract and universal way. The specific significance of an object, emotion, word, or social situation depends on the contextual effects. During normal cognition, our brains do not process targets and contexts separately; rather, targets are in context.

circles

Behavioural variant frontotemporal dementia and the social context

The “behavioral variant of frontotemporal dementia“ (bvFTD) is characterised by insidiously progressive changes in personality and social interaction that typically precede other cognitive deficits.  Patients may present with compulsiveness, perseverations, or stereotyped repetitive acts, loss of self-consciousness, diminished interest for activities or hobbies, or withdrawal and apathy.  Increased appetite with a tendency for sweet foods is common, and hypersexuality and hyperorality may develop, especially in the advanced stages of the disease.

Early diagnosis is difficult because behavioural problems, invariably reported by friends or family, dominate the clinical picture while cognitive functions are still relatively intact. This is why it is so important to appreciate that dementia does not equal memory problems in every single case (and this is discussed in chapter 18). People with bvFTD often score normally on the Mini-Mental State Examination (“MMSE”), and conventional structural brain imaging (CT and MRI) may not be sensitive to the early changes associated with bvFTD at all. Therefore, early diagnosis relies on clinical interviews and caregiver reports; it can be considerably difficult to distinguish bvFTD from primary psychiatric syndromes.

Patients with bvFTD are now reported consistently to demonstrate reliably deficits in several domains of social cognition such as recognising emotions in facial expressions, empathy processing, decision-making, figurative language, theory of mind, and interpersonal norms.  Little was known about the brains of such patients from an neuroimaging perspective. In particular, given the nature of the cognitive deficits demonstrated by these patients, the authors postulated that, relatively early in the course of the disease, the ventromedial (VMPFC) (or orbitofrontal) cortex is a major locus of dysfunction and that this may relate to the behavioural presentation of these patients clinically described in the individual case histories. A greater definition of the rôle of the ventral frontal cortex, especially given findings in the animal literature, in reversal learning and decision has been a highly influential tranche of research subsequently (Clark, Cools and Robbins, 2004).

At approximately the same time, Lough, Gregory and Hodges (2001) demonstrated relatively intact general neuropsychological and executive function, but extremely poor performance on tasks of theory of mind (ToM). This indicates a dissociation of social cognition and executive function suggesting that in psychiatric presentations of bv-FTD there may be a fundamental deficit in theory of mind independent of the level of executive function. The implications of this finding for diagnostic procedures and possible behavioural management are discussed.

Liu and colleagues (Liu et al., 2004) later compared the behavioral features and to investigate the neuroanatomical correlates of behavioral dysfunction in anatomically defined temporal and behavioural variants of frontotemporal dementia (tvFTD and bvFTD). Volumetric measurements of the frontal, anterior temporal, ventromedial frontal cortical (VMFC), and amygdala regions were made in 51 patients with FTD and 20 normal control subjects, as well as 22 patients with dementia of Alzheimer type (DAT) who were used as dementia controls. FTD patients were classified as bvFTD or tvFTD based on the relative degree of frontal and anterior temporal volume loss compared with controls. Behavioural symptoms, cerebral volumes, and the relationship between them were examined across groups. Both variants of FTD showed significant increases in rates of elation, disinhibition, and aberrant motor behavior compared with DAT. The bvFTD group also showed more anxiety, apathy, and eating disorders, and tvFTD showed a higher prevalence of sleep disturbances than DAT. The only behaviours that differed significantly between bvFTD and tvFTD were apathy, greater in bvFTD, and sleep disorders, more frequent in tvFTD. BvFTD was associated with greater frontal atrophy and tvFTD was associated with more temporal and amygdala atrophy compared with AD, but both groups showed significant atrophy in the VMFC compared with DAT, which was not associated with VMFC atrophy. In FTD, the presence of many of the behavioral disorders was associated with decreased volume in right-hemispheric regions.

Using magnetic resonance imaging (MRI), tensor-based morphometry (TBM), Lu et al. (Lu et al., 2013) was finally used to determine distinct patterns of atrophy between these three clinical groups. The authors concluded that The bvFTD, SV-PPA, and NF-PPA groups displayed distinct patterns of progressive atrophy over a one-year period that correspond well to the behavioral disturbances characteristic of the clinical syndromes. More specifically, the bvFTD group showed significant white matter contraction and presence of behavioral symptoms at baseline predicted significant volume loss of the ventromedial prefrontal cortex. These areas of structural atrophy seem also to be correlated to functional deficits in the case of bvFTD, and now seem to suggest a dissociation in dysfunction even between reversal learning and decision learning deficits at a finer level.

Finally, to complete things, Bertoux and colleagues (Bertoux et al., 2012b) reported that gray matter volume within BA 9 in the medial prefrontal was correlated with scores on the emotion recognition subtest of the he social cognition and emotional assessment”, and the severity of apathetic symptoms in the apathy scale covaried with gray matter volume in the lateral prefrontal cortex (BA 44/45).

The “social context network model”

At a phenomenological level, context-based predictions make social cognition more efficient. Prototypical situations in the environment are represented in “context frames” that integrate information about the meanings of social targets (e.g., an emotional face, a speech) that are likely to appear in a specific scene with information about their relationships.

Ibañez and Manes (2012) proposed that there exists a cortical network that mediates the processing of such contextual associations. This social context network involves regions of the frontal, insular, and temporal cortices. They postulate that frontal areas (e.g., orbitofrontal cortex, lateral prefrontal cortex, superior orbital sulcus) update and associate ongoing contextual information in relation to episodic memory and target-context associations. The temporal regions (amygdala, hippocampus, perirhinal and para-hippocampal cortices) index the value learning of target-context associations. Finally, the insular cortex coordinates internal and external milieus in an internal motivational state. In this way, the insula would provide information integration from internal states and social contexts to produce a global feeling state.

The initial symptoms of FTD reflect the involvement of orbitofrontal cortex as well as the disruption of the rostral limbic system including the insula, the anterior cingulate cortex, the striatum, the amygdala, and the medial frontal lobes. This system is involved in a number of processes such as the evaluation of the motivational or emotional content of internal and external stimuli, error detection, response selection and decision-making, and subsequent regulation of context-dependent behaviours. Recent neuroimaging studies suggest that patients with FTD show predominantly right frontal, anterior insular, and anterior cingulate deterioration, with pronounced orbitofrontal cortex atrophy. Additionally, some studies have reported correlations between behavioural symptoms and brain structures, suggesting that the right orbitofrontal cortex regulates behavior together with a predominantly right-side network involving the insula and striatum. In addition, voxel-based morphometry studies have shown that patients with bvFTD have significant gray matter loss in the anterior insula and in a variety of prefrontal areas.

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Related articles

Where is the policy generally heading?

Shibley Rahman 1 Comment

he most ‘perfect’ scenario for dementia screening would be to identify dementia in a group of individuals who have absolutely no symptoms might have subtle changes on their volumetric MRI scans, or might have weird protein fragments in their cerebrospinal fluid through an invasive lumbar culture; and then come up with a reliable way to stop it in its tracks  The cost, practicality and science behind this prohibit this approach.

There are well defined criteria for screening, such as the “Wilson Jungner criteria“. Prof Carol Brayne from the University of Cambridge has warned against the perils of backdoor screening of dementia, and the need for evidence-based policy, publicly in an article in the British Medical Journal:

“As a group of clinical and applied researchers we urge governments, charities, the academic community and others to be more coordinated in order to put the policy cart after the research horse. Dementia screening should neither be recommended nor routinely implemented unless and until there is robust evidence to support it. The UK can play a unique role in providing the evidence base to inform the ageing world in this area, whilst making a positive difference to the lives of individuals and their families in the future.”

However, a problem has arisen in how aggressively to find new cases of dementia in primary care, and a lack of acknowledgement by some that incentivising dementia diagnosis might possibly have an untoward effect of misdiagnosing (and indeed mislabelling) some individuals, who do not have dementia, with dementia. Unfortunately there are market forces at work here, but the primary consideration must be the professional judgment of clinicians.

Diagnosing dementia

There is no single test for dementia.

A diagnosis of dementia can only be confirmed post mortem, but there are ‘tests’ in vivo which can be strongly indicative of a specific dementia diagnosis (such as brain biopsy for Variant Creutzfeld-Jacob disease or cerebral vasculitis), or specific genetic mutations on a blood test (such as for relatively rare forms of the dementia of the Alzheimer type).

Memory vs non-memory functions in CANTAB

CANTABmobile is a new touchscreen test for identifying memory impairment, being described as a ‘rapid memory test’. The hope is that memory deficits might be spotted quickly in persons attending the National Health Service, and this is indeed a worthy cause potentially. In the rush to try to diagnose dementia quickly (and I have explained above the problem with the term “diagnose dementia”), it is easy to conflate dementia and memory problems. However, I demonstrated myself in a paper in Brain in 1999 using one of the CANTAB tests that patients with behavioural variant frontotemporal dementia (bvFTD) were selectively impaired on tests sensitive to prefrontal lobe function involving cognitive flexibility and decision-making. I demonstrated further in a paper in the European Journal of Neuroscience in 2003 that such bvFTD patients were unimpaired on the CANTAB paired associates learning test.

bvFTD is significant as it is a prevalent form of dementia in individuals below the age of 60. The description given by Prof John Hodges in the current Oxford Textbook of Medicine chapter on dementia is here. Indeed, this chapter cites my Brain paper:

“Patients present with insidiously progressive changes in personality and behaviour that refl ect the early locus of pathology in orbital and medial parts of the frontal lobes. There is often impaired judgement, an indifference to domestic and professional responsibilities, and a lack of initiation and apathy. Social skills deteriorate and there can be socially inappropriate behaviour, fatuousness, jocularity, abnormal sexual behaviour with disinhibition, or theft. Many patients are restless with an obsessive–compulsive and ritualized pattern of behaviour, such as pacing or hoarding. Emotional labiality and mood swings are seen, but other psychiatric phenomena such as delusions and hallucinations are rare. Patients become rigid and stereotyped in their daily routines and food choices. A change in food preference towards sweet foods is very characteristic. Of importance is the fact that simple bedside cognitive screening tests such as the Mini-Mental State Examination (MMSE) are insensitive at detecting frontal abnormalities. More detailed neuropsychological tests of frontal function (such as the Wisconsin Card Sorting Test or the Stroop Test) usually show abnormalities. Speech output can be reduced with a tendency to echolalia (repeating the examiner’s last phrase). Memory is relatively spared in the earl  stages, although it does deteriorate as the disease advances. Visuospatial function remains remarkably unaffected. Primary motor and sensory functions remain normal. Primitive refl exes such as snout, pout, and grasp develop during the disease process. Muscle fasciculations or wasting, particularly affecting the bulbar musculature, can develop in the FTD subtype associated with MND.”

Memory tests, mild cognitive impairment and dementia of Alzheimer type

Nobody can deny the undeniable benefits of a prompt diagnosis, when correct, of dementia, but the notion that not all memory deficits mean dementia is a formidable one. Besides, this tweeted by Prof Clare Gerada, Chair of the Royal College of General Practitioners, to me this morning I feel is definitely true,

normal ageing

A political drive, almost in total parallel led by the current UK and US governments, to screen older people for minor memory changes could potentially be leading to unnecessary investigation and potentially harmful treatment for what is arguably an inevitable consequence of ageing. There are no drugs that prevent the progression of dementia according to human studies, or are effective in patients with mild cognitive impairment, raising concerns that once patients are labelled with mild cognitive deficits as a “pre-disease” for dementia, they may try untested therapies and run the risk of adverse effects.

The idea itself of the MCI as a “pre-disease” in the dementia of Alzheimer type is itself erroneous, if one actually bothers to look at the published neuroscientific evidence. A mild cognitive impairment (“MCI”) is a clinical diagnosis in which deficits in cognitive function are evident but not of sufficient severity to warrant a diagnosis of dementia (Nelson and O’Connor, 2008).It is claimed that on the CANTABmobile website that:

statement

However, the evidence of progression of MCI (mild cognitive impairment) to DAT is currently weak. It might be attractive to think that MCI is a preclinical form of dementia of Alzheimer Type, but unfortunately the evidence is not there to back this claim up at present: only approximately 5-10% and most people with MCI will not progress to dementia even after ten years of follow-up (Mitchell and Shiri-Feshki, 2009).

An equally important question is also the specificity and sensitivity of the CANTABmobile PAL test. Quite a long explanation is given on their webpage again:

Specificity and sensitivity of PAL

However, the reference that is given is unrelated to the data presented above. What should have appeared there was a peer-reviewed paper analysing sensitivity and sensitivity of the test, across a number of relevant patient groups, such as ageing ‘normal’ volunteers, patients with geriatric depression, MCI, DAT, and so on. A reference instead is given to a paper in JAMA which does not even mention CANTAB or CANTABmobile.

NICE, QOF and indicator NM72

A description of QOF is on the NICE website:

“Introduced in 2004 as part of the General Medical Services Contract, the QOF is a voluntary incentive scheme for GP practices in the UK, rewarding them for how well they care for patients.

The QOF contains groups of indicators, against which practices score points according to their level of achievement. NICE’s role focuses on the clinical and public health domains in the QOF, which include a number of areas such as coronary heart disease and hypertension.

The QOF gives an indication of the overall achievement of a practice through a points system. Practices aim to deliver high quality care across a range of areas, for which they score points. Put simply, the higher the score, the higher the financial reward for the practice. The final payment is adjusted to take account of the practice list size and prevalence. The results are published annually.”

According to guidance on the NM72 indicator from NICE dated August 2013, this indicator (“NM72″) comprises the percentage of patients with dementia (diagnosed on or after 1 April 2014) with a record of FBC, calcium, glucose, renal and liver function, thyroid function tests, serum vitamin B12 and folate levels recorded up to 12 months before entering on to the register  The timeframe for this indicator has been amended to be consistent with a new dementia indicator NM65 (attendance at a memory assessment service).

Strictly speaking then QOF is not about screening as it is for patients with a known diagnosis of dementia. If this battery of tests were done on people with a subclinical amnestic syndrome as a precursor to a full-blown dementia syndrome with an amnestic component, it might conceivably be ‘screening’ depending on how robust the actual diagnosis of the dementia of those individuals participating actually is. As with all these policy moves, it is very easy to have unintended consequences and mission creep.

According to this document,

“There is no universal consensus on the appropriate diagnostic tests to be undertaken in people with suspected dementia. However, a review of 14 guidelines and consensus statements found considerable similarity in recommendations (Beck et al. 2000). The main reason for undertaking investigations in a person with suspected dementia is to exclude a potentially reversible or modifying cause for the dementia and to help exclude other diagnoses (such as delirium). Reversible or modifying causes include metabolic and endocrine abnormalities (for example, vitamin B12 and folate deficiency, hypothyroidism, diabetes and disorders of calcium metabolism).

The NICE clnical guideline on dementia (NICE clinical guideline 42) states that a basic dementia screen should be performed at the time of presentation, usually within primary care. It should include:

  • routine haematology
  • biochemistry tests (including electrolytes, calcium, glucose, and renal and liver function)
  • thyroid function tests
  • serum vitamin B12 and folate levels.”

It is vehemently denied that primary care is ‘screening’ for dementia, but here is a QOF indicator which explicitly tries to identify reversible causes of dementia in those with possible dementia.

There are clearly issues of valid consent for the individual presenting in primary care.

Prof Clare Gerada has previously warned to the effect that it is crucial that QOF does not “overplay its hand”, for example:

“QOF is risking driving out caring and compassion from our consultations. We need to control it before it gets more out of control – need concerted effort by GPC and RCGP.”

Conclusion

Never has it been more important than to heed Prof Brayne’s words:

“As a group of clinical and applied researchers we urge governments, charities, the academic community and others to be more coordinated in order to put the policy cart after the research horse.”

In recent years, many glib statements, often made by non-experts in dementia, have been made regarding the cognitive neuroscience of dementia, and these are distorting the public health debate on dementia to its detriment. An issue has been, sadly, a consideration of what people (other than individual patients themselves) have had to gain from the clinical diagnosis of dementia. At the moment, some politicians are considering how they can ‘carve up’ primary care, and some people even want it to act as a referral source for private screening businesses. The “NHS MOT” would be feasible way of the State drumming up business for private enterprises, even if the evidence for mass screening is not robust. The direction of travel indicates that politicians wish to have more ‘private market entrants’ in primary care, so how GPs handle their QOF databases could have implications for the use of ‘Big Data’ tomorrow.

With headlines such as this from as recently as 18 August 2013,

£! headline

this is definitely ‘one to watch’.

Further references 

Beck C, Cody M, Souder E et al. (2000) Dementia diagnostic guidelines: methodologies, results, and implementation costs. Journal of the American Geriatrics Society 48: 1195–203

Mitchell, A.J., and Shiri-Feshki, M. (2009) Rate of progression of mild cognitive impairment to dementia -meta-analysis of 41 robust inception cohort studies. Acta Psychiatr Scand, 119(4), pp. 252-65.

Nelson, A.P., and O’Connor, M.G. (2008) Mild cognitive impairment: a neuropsychological perspective, CNS Spectr, 13(1), pp. 56-64.

National Institute for Health and Clinical Excellence (2006) Dementia. Supporting people with dementia and their carers in health and social care. NICE clinical guideline 42

Many thanks to @val_hudson for a useful critical comment about an earlier version of this blogpost.