Cognitive profiles of autopsy-confirmed Lewy body variant vs pure Alzheimer disease

Objective: To compare the cognitive profiles of patients with autopsy-confirmed Alzheimer disease (AD), with or without concomitant Levy bodies, on 2 dementia screening measures. Methods: Profiles on subtests of the Mattis Dementia Rating Scale (range, 105-125) and of component items of the Mini-Mental State Examination were compared between 23 patients with uncomplicated AD and 23 patients with concomitant AD and Lewy body pathology (Lewy body variant [LBV]). Results: Although the groups did not differ significantly regarding age, years of education, total Mini-Mental State Er;amination score, or total Mattis Dementia Rating Scale score, the AD group performed significantly worse than the LBV group on the Mattis Dementia Rating Scale Memory subscale (P<.0.05). In contrast, the LBV group demonstrated poorer performance than the pure AD group on the Initiation/Perseveration subscale (P<.02). The groups did not differ significantly on the Attention, Construction or Conceptualization subscales. The same overall pattern of results was obtained when subgroups with mild to moderate and moderate to severe dementia were examined separately, with the additional finding that in the mild-to-moderate range patients with dementia and IBV performed worse than patients with pure AD on the Construction subscale. Conclusions: Tthe difference in pattern of cognitive deficits among patients with pure AD vs those with AD and LBV is similar to that seen between AD and more subcortical/frontal dementias leg, Huntington disease) This suggests that the concomitant Lewy body pathology significantly contributes to the presentation of the cognitive dysfunction in individuals with LBV.