Slowing on quantitative spectral EEG is a marker for rate of subsequent cognitive and functional decline in early Alzheimer disease

The relation between quantitative spectral electroencephalogram (qEEG) para meters and subsequent rate of cognitive, functional, and behavioral decline in 82 consecutive patients with early probable Alzheimer disease (NINCDS-A DRDA criteria) was examined in a prospective study. The qEEG was performed at initial examination and global cognitive function, activities of daily l iving, and behavior were assessed at initial evaluation and after a period of 6 months. Using multiple linear regression analysis,higher frontocentral and parieto-occipital theta values, lower parieto-occipital beta values, a nd lower peak frequency were significantly associated with more decline in global cognitive function over the follow-up period. In addition, lower par ieto-occipital beta values were significantly related to more decline in ac tivities of daily living. These associations were independent of demographi c (age, sex, and education) and disease characteristics [initial Cambridge Examination for Mental Disorders of the Elderly Cognitive test (CAMCOG) or Mini-Mental State Examination scores, estimated duration of symptoms, estim ated prior rate of decline, and dementia severity]. In a separate multiple logistic regression analysis, prediction of rapidly progressive decline, de fined as 8 or more points decline in CAMCOG scores (n = 21), could be made with parieto-occipital and frontocentral beta values. The results suggest t hat slowing on qEEG is a marker for subsequent rate of cognitive and functi onal decline in mildly demented AD patients, independent of demographic or disease characteristics.