CATEGORY FLUENCY IS ALSO PREDOMINANTLY AFFECTED IN SWISS ALZHEIMERS-DISEASE PATIENTS

Objectives - To establish the comparative efficacy to differentiate be tween Swiss patients with dementia of the Alzheimer type (DAT) and eld erly normal control subjects (NC) on two different verbal fluency task s: category fluency and letter fluency. Material and methods - Fifty S wiss German DAT patients in the early stages of the disease and 50 mat ched normal control subjects were compared on letter and category flue ncy tasks. Results - DAT patients exhibited an overproportional impair ment on category fluency as compared with letter fluency. Receiver ope rating characteristic curves (ROC) showed that category fluency correc tly classified a significantly higher number of DAT patients and NC su bjects (84%) than letter fluency (70%). Conclusion - As similar findin gs have been described for English-speaking DAT patients, we conclude that deficiencies in category fluency are a general phenomenon, reflec ting impaired structures of semantic knowledge occurring early in the course of Alzheimer's disease.