NEUROPSYCHOLOGICAL HETEROGENEITY IN MILD ALZHEIMERS-DISEASE

In order to investigate neuropsychological differences in patients wit h mild AD, we carried out a pilot study on 28 patients with a clinical diagnosis of mild dementia (CDR: 0.5-1) using an extensive neuropsych ological battery, in comparison with 28 normal controls. The results o f a cluster analysis, applied on the neuropsychological variables, sho wed the existence of at least two main subgroups of patients. Cluster 1 patients had a mean age of 61.1 years and showed a greater impairmen t on measures of language, abstract reasoning and verbal fluency: clus ter 2 patients, with a mean age of 72.0, had more severe impairment in memory function. These preliminary results may suggest the existence of different subtypes of AD characterized by selective neuropsychologi cal deterioration in the early stages of the disease.