Clinical characterization of mild cognitive impairment as a prodrome to dementia with Lewy bodies.

Limited information regarding the specificity of mild cognitive impairment (MCI) as it relates to dementia with Lewy bodies (DLB) exists. Here, we summarize the clinical phenotype of MCI in clinically suspect DLB. Ten patients with a primary diagnosis of MCI and secondary diagnoses of DLB were identified. Patients underwent clinical neurological and neuropsychological evaluation that included application of McKeith criteria. We found parkinsonism and gait abnormality in 9 of the 10 patients; fluctuations in 8 of the 10; and hallucinations and dream enactment behavior in 5 of the 10. Of the 10 cases, 4 were classified as nonamnestic MCI and 6 were amnestic MCI. Of the 10 cases, 9 displayed executive and/or visuospatial dysfunction. Of the 10 cases, 6 have progressed to DLB. Progression of MCI to DLB is not dependent on memory impairment. The presence of core clinical features-parkinsonism and cognitive fluctuations-and predominant executive and visuospatial dysfunction ± memory impairment is suggestive of a prodromal DLB presentation.