#PreventiveNeurology: misdiagnosis needs a solution

How are we going to get the general population to sign-up for screening for neurodegenerative diseases? #PreventiveNeurology 

Two of the three diseases we are targeting as part of our Preventive Neurology initiative will capture people with Diffuse Lewy Body (DLB) disease, i.e. Parkinson's disease and all-cause dementia. The BMJ commentary and DLB consensus report highlight the problem of misdiagnosis. If we are careful and embed in our prediction algorithms the right patient-related outcome measures and cognitive testing we should be able to identify a cohort of people with early DLB. May be this is wishful thinking. One of the obstacles we are going to find is getting members of the general population to sign-up for screening. Any ideas? 

Joseph Freer. UK lags far behind Europe on diagnosis of dementia with Lewy bodies. BMJ 2017;358:j3319

Excerpts:

..... Around half of UK patients who have dementia with Lewy bodies (DLB)—about 60 000 people—have it misdiagnosed, usually as the far more common Alzheimer’s disease, says the DLB Consortium in updated recommendations on diagnosing and managing DLB.

.... A survey of electronic health records of 500 patients in London, who met the criteria for a DLB diagnosis, showed that only 50% had the condition diagnosed and that only five people received the imaging that is now recommended during the diagnostic process.

.... DLB is much more common than previously thought, accounting for around 15% of dementia cases.

..... Misdiagnosis and underdiagnosis of DLB is a particular problem for patients in whom symptoms of psychosis and parkinsonism are common: patients with DLB who are treated with antipsychotics have an increased risk of mortality, as well as worsening parkinsonian symptoms. Patients with DLB also respond differently to medicines used commonly in Alzheimer’s disease and Parkinson’s disease.

McKeith et al. Diagnosis and management of dementia with Lewy bodies: Fourth consensus report of the DLB Consortium. Neurology July 4, 2017 vol. 89 no. 1 88-100

The Dementia with Lewy Bodies (DLB) Consortium has refined its recommendations about the clinical and pathologic diagnosis of DLB, updating the previous report, which has been in widespread use for the last decade. The revised DLB consensus criteria now distinguish clearly between clinical features and diagnostic biomarkers, and give guidance about optimal methods to establish and interpret these. Substantial new information has been incorporated about previously reported aspects of DLB, with increased diagnostic weighting given to REM sleep behavior disorder and 123iodine-metaiodobenzylguanidine (MIBG) myocardial scintigraphy. The diagnostic role of other neuroimaging, electrophysiologic, and laboratory investigations is also described. Minor modifications to pathologic methods and criteria are recommended to take account of Alzheimer disease neuropathologic change, to add previously omitted Lewy-related pathology categories, and to include assessments for substantia nigra neuronal loss. Recommendations about clinical management are largely based upon expert opinion since randomized controlled trials in DLB are few. Substantial progress has been made since the previous report in the detection and recognition of DLB as a common and important clinical disorder. During that period it has been incorporated into DSM-5, as major neurocognitive disorder with Lewy bodies. There remains a pressing need to understand the underlying neurobiology and pathophysiology of DLB, to develop and deliver clinical trials with both symptomatic and disease-modifying agents, and to help patients and carers worldwide to inform themselves about the disease, its prognosis, best available treatments, ongoing research, and how to get adequate support.