Dementia with Lewy bodies

Synucleinopathies, with and without dementia, encompass a wide range of diseases including Parkinson's disease, multiple system atrophy, rapid eye movement (REM) sleep behavior disorder, and dementia with Lewy bodies (DLB). DLB is a neurodegenerative disorder resulting in slowly progressive and unrelenting dementia until death. Prevalence studies suggest that it is the second most common dementing illness in the elderly. The neuropathologic findings of DLB show a wide anatomic range. Lewy bodies and Lewy-related pathology are found from the brain stem to the cortex and, in many cases, associated with concurrent Alzheimer's disease pathology. A recent international consortium on DLB has resulted in revised criteria for the clinical and pathological diagnosis of DLB incorporating new information about the core clinical features and improved methods for their assessment. The presentation of DLB is typically one of cortical and subcortical cognitive impairments, with worse visuospatial and executive dysfunction than Alzheimer's disease. There may be relative sparing of memory especially in the early stages. Core clinical features of DLB include fluctuating attention, recurrent visual hallucinations, and parkinsonism. Suggestive features include REM sleep behavior disorder, severe neuroleptic sensitivity, and low dopamine transporter uptake in the basal ganglia on functional neuroimaging. Additional supportive features that commonly occur in DLB, but with lower specificity, include repeated falls and syncope, transient, unexplained loss of consciousness, severe autonomic dysfunction, hallucinations in other modalities, systematized delusions, depression, relative preservation of medial temporal lobe structures on structural neuroimaging, reduced occipital activity on functional neuroimaging, prominent slow wave activity on electroencephalogram, and low uptake myocardial scintigraphy. Management of DLB includes pharmacological and nonpharmacological interventions for its cognitive, neuropsychiatric, motor, and sleep disturbances.