CLINICAL AND NEUROPSYCHOLOGICAL DIFFERENCES BETWEEN PATIENTS WITH EARLIER AND LATER ONSET OF ALZHEIMERS-DISEASE - A CERAD ANALYSIS .12.

To determine whether the age of onset of Alzheimer's disease (AD) is r elated to the expression and rate of decline of this disorder, we exam ined the clinical and neuropsychological performance of 421 patients e ntered into the Consortium to Establish a Registry for Alzheimer's Dis ease and followed annually for up to 4 years. Statistical analyses wer e based on multivariable logistic regression analysis for dichotomous clinical measures and multivariable linear regression analysis for psy chometric measures. All analyses examined the effect of age after cont rolling for gender, education, and stage of dementia. Clinical informa tion obtained on entry into the study indicated that younger patients performed more poorly on measures of language and concentration, and o lder patients performed more poorly on measures of memory and orientat ion. On neuropsychological measures at entry, younger patients perform ed more poorly on praxis and had significantly higher scores on confro ntation naming. Younger age predicted a significantly faster rate of p rogression for all neuropsychological measures. These findings support the concept of age-related clinical subtypes of AD.