WAIS-R intersubtest scatter in patients with dementia of Alzheimer's type.

This study explored the relationship between three indices of intersubtest scatter and level of cognitive deterioration in a sample of 104 patients with dementia of Alzheimer's type, who ranged in age between 52 and 84 years. Scatter was highly related to education and premorbid level of functioning. Advancement of dementia was shown to be associated with decrease in scatter, which suggests caution in interpretation of high magnitude of inter-subtest scatter as an indication of brain dysfunction. Easy-to-calculate range of scatter proved to be adequate measure of scatter. Calculation of more complex indices, such as PVI, provides only minimal incremental gain.