Dementia and cognitive disorders

Research criteria for the diagnosis of prodromal dementia with Lewy bodies

Dementia Lewy bodies (DLB) may present in the prodromal stage as mild cognitive impairment, delirium-onset or psychiatric-onset and authors proposed its key features with evidence for usefulness of biomarkers.

Dementia with Lewy bodies (DLB) may present in the prodromal stage as mild cognitive impairment, delirium-onset or psychiatric-onset. The MCI-LB prototypic prodromal is best characterized by single- or multidomain non-amnestic MCI, or as multidomain amnestic MCI. A number of other symptoms in combination with cognitive impairment has predictive value, like REM sleep behaviour disorder or symptoms of parkinsonism. To fulfil criteria for probable MCI-LB patient or caregiver must report cognitive decline with objective evidence of impairment in one or more cognitive domains, preservation or minimally affected functionality and presence of 1 or more core clinical features (fluctuating cognition, recurrent visual hallucinations, RBD and parkinsonism). For differentiation between PD-MCI and prodromal DLB the 1-year rule may be helpful. Prodromal delirium-onset DLB should be suspected particularly in patients in whom adequate provoking factors for the delirium are not found, with prolonged or recurrent delirium or who later develop progressive cognitive decline or subsequent dementia. Key features of psychiatric-onset DLB are late-onset major depressive disorder or late-onset psychosis, but it may also present with apathy, anxiety, and depression and it has to be sufficiently severe to require hospitalization. Core clinical presentation of DLB in delirium-onset type is not helpful and in psychiatric-onset is often hard to evaluate. As proposed biomarkers they have mentioned DAT- SPECT and MIBG cardiac scintigraphy and as potential biomarkers they have evaluate usefulness of quantitative EEG (qEEG), MRI, FDG-PET, CSF α-synuclein aggregates, gait analysis and abnormalities in colour vision discrimination.

These prodromal DLB criteria will surely stimulate further research.

Key Points:

Dementia with Lewy bodies; prodromal stage; biomarker; criteria

References:

Ian G. McKeith, F Med Sci, MD, Tanis J. Ferman, PhD, Alan J. Thomas, PhD, Fr´ed´eric Blanc, MD, Bradley F. Boeve, MD, Hiroshige Fujishiro, MD, Kejal Kantarci, MD, MS, Cristina Muscio, PhD, John T. O’Brien, F Med Sci, DM, Ronald B. Postuma, MD, MSc, Dag Aarsland, PhD, Clive Ballard, MD, Laura Bonanni,MD, PhD, Paul Donaghy, PhD,Murat Emre,MD, James E. Galvin,MD,MPH, Douglas Galasko,MD, Jennifer G. Goldman, MD, MS, Stephen N. Gomperts, MD, PhD, Lawrence S. Honig, MD, PhD, Manabu Ikeda, MD, PhD, James B. Leverenz, MD, Simon J.G. Lewis, MD, Karen S. Marder, MD, MPH, Mario Masellis, MD, PhD, David P. Salmon, PhD, John Paul Taylor, MB, BS, PhD, Debby W. Tsuang, MD, Zuzana Walker, MD, and Pietro Tiraboschi, MD, for the prodromal DLB Diagnostic Study Group. Research criteria for the diagnosis of prodromal dementia with Lewy bodies. Neurology® 2020;94:1-13. doi:10.1212/WNL.0000000000009323. https://pubmed.ncbi.nlm.nih.gov/32241955/