Relation of quantitative indexes of concurrent α-synuclein abnormalities to clinical outcome in autopsy-proven Alzheimer disease

Background: Lewy bodies (LBs) and Lewy neurites are frequent concomitant neuropathologic observations in clinical and neuropathologically defined Alzheimer disease (AD), but their relation to clinical features inADis uncertain. Most studies used semiquantitative measures to determine the presence or absence of LB abnormalities. Objective: To determine the clinical consequences of LB abnormalities in the setting of AD. Design: Prospective study. Setting: Three outpatient research and treatment centers. Participants: Fourteen autopsy cases with a pathologic diagnosis of AD abnormalities and concomitant LBs followed semiannually for up to 8 years (mean age at intake, 72 years; mean age at death, 77 years; mean education, 15 years; 12 women). Main Outcome Measures: The modified Mini-Mental State Examination was used to assess cognitive function. The Unified Parkinson Disease Rating Scale was used to rate extrapyramidal motor signs. Hallucinations were evaluated using the Columbia University Scale for Psychopathology in Alzheimer's Disease. Time from the first evaluation in which diagnostic criteria for probable AD were met to death was used to determine illness duration. Quantitative measures of LB abnormalities were obtained for the frontal cortex, entorhinal cortex, substantia nigra, and hippocampus. Results: Independent-samples t tests were used to assess whether the degree of LB abnormality varied as a function of the presence or absence of hallucinations and extrapyramidal signs. Pearson r correlations were run to examine whether there was a relation among LB abnormalities, cognitive function, and illness duration. There was no relation between quantitative neuropathologic indexes of LB abnormalities and clinical outcome. Conclusion: The variability of clinical features in AD was not related to the presence or degree of LB abnormalities.