Dementia with Lewy bodies: why early detection is key to care and quest

Ian McKeith is an award winning expert in dementia with Lewy bodies (DLB) and led the dementia with Lewy bodies Consortium in producing key guidelines to detecting the characteristic signs of this type of dementia in 1996, and then further updates in 2005 and 2017. Across a period of 30 years, his work has played a vital role in heightening our understanding of DLB, compared to other forms of dementia.

Published this month in the journal Neurology, the most recent set of guidelines in this area aim to move the time of diagnosis of DLB to an earlier point, where intervention is likely to be most beneficial.

In this blog, Professor McKeith outlines why early prevention can lead the way in not only improving the lives of those diagnosed, but can also set the tone for scientific studies focused on evaluating biomarkers.

Dementia with Lewy bodies accounts for between 10 and 15% of all cases of dementia, meaning there are at least 100,000 people living with this form of dementia in the UK right now[1]. We know that the number of DLB cases diagnosed varies markedly between clinics with even the most vigilant still probably significantly under-diagnosing the condition. A frequent misdiagnosis of DLB is as Alzheimer’s disease, the situation being complicated by the fact that many patients have a mixture of the two disorders.

It is becoming clear that in diseases like this, which cause significant degeneration of brain cells, achieving a cure by reversal of damaged tissue, seems unlikely; prevention is a much more effective strategy. This is why we have turned our attention towards detecting the earliest stages of the disease, before clinical symptoms become debilitating, which is when effective intervention might be more feasible.

This early, pre-dementia stage of disease is sometimes referred to as “prodromal”, (from the Greek prodromos, meaning forerunner) and our group have over the past few years, turned their attention to identifying the characteristics of prodromal DLB. Unsurprisingly, cognitive decline is the most common early sign of prodromal DLB, but this typically differs from the recent memory loss which characterizes the most common type of dementia (Alzheimer’s disease). Early DLB may present instead with attentional lapses and visuo-perceptual difficulties (difficulty recognising objects based on their form, pattern and colour), either alone or combined with memory failure. Lesser known by the medical community, is that DLB may also start with episodes of delirium (acute confusional state), or with the late onset of psychiatric symptoms, varying from anxiety and agitation, through to severe depression and delusions.

The guideline urges clinicians treating older people to be vigilant to these early signs of DLB disease and when they are present, to use a battery of recommended biomarker tests to investigate further.

In terms of wider adoption, we recognise that these recommendations need further validation before they are introduced into routine clinical practice, but what we can be clear on, is that this new data can be used immediately for research application e.g. improving diagnostic test development and enabling early stage of illness clinical trials. We are already applying these techniques in clinical translational studies supported by the NIHR Newcastle BRC’s Dementia research theme and we anticipate that this is an area in which diagnostic practice and clinical management will evolve significantly in the coming years.

These guidelines (available in full using the link below) are published as the NIHR announces Newcastle as a designated Academic Health Science Centre (AHSC); a collaborative effort between health and university partnerships, with the aim of improving health and care through increased translation of discoveries from early scientific research into benefits to patients; an ethos embedded in the structure of the NIHR-funded  Biomedical Research Centres. Dementia being an area of focus for both the Newcastle BRC and the NIHR nationally, our work here in Newcastle is well placed to not only respond to a national target, but also work in an integrative way with our partners, in order to ensure discoveries like this, make their way to patients and their families.

Publication details: McKeith IG, Ferman TJ, Thomas AJ, et al. Research criteria for the diagnosis of prodromal dementia with Lewy bodies. Neurology. 2020:94(7);1-13.

Ian McKeith is Professor of Old Age Psychiatry at Newcastle University, a Fellow of the Academy of Medical Sciences and a Fellow of the Royal Society of Biology. He is a Scientific Advisor for the Lewy Body Dementia Association (LBDA). See him at the next International Lewy Body Dementia Conference (ILBD 2021) will be held June 16th to 18th 2021 at Newcastle Gateshead Hilton Hotel (details to follow).

¹ Source: https://www.lewybody.org/about-lbd/