Changes of the relative severity of naming, fluency and recall impairment in the course of dementia of the Alzheimer type.

In a longitudinal study of 90 patients with mild to moderate dementia of the Alzheimer type (DAT) we investigated the relative severity of impairment in a confrontation naming, a categorical word fluency and a word list recall task. Severity of impairment was assessed in comparison to a healthy age-matched control group. At baseline, confrontation naming and fluency deficits were about equally often the most severe deficit. The number of patients with most severe naming deficits increased from mild to moderate dementia and from baseline to 1-year follow-up. Word recall was the most severe deficit only in a minority of patients. An addition of lexical-semantic and visual-perceptive dysfunctions is discussed as a possible cause for the shift towards naming deficits in the course of the disease.