P3‐193: The utility of the verbal fluency test in early stage of Alzheimer's disease: Preliminary study

Although verbal fluency test is regarded as a sensitive test to prefrontal lesions, it might be affected by patient's language function or semantic knowledge. Education or age also can be the factors that have influence on the result of verbal fluency test. The present study is a preliminary study to assess the utility of the verbal fluency test by focusing on the relation between verbal fluency test and test for frontal function or other cognitive domain such as language and memory. We studied 89 patients with probable AD who were newly diagnosed, untreated, and underwent detailed neuropsychological evaluation at the initial visit. We divided them as 3 groups according to MMSE score, such as MCI, mild and moderate, and excluded the patients with severe cognitive impairment. We analyzed their demographic features, the correlation between the result of verbal fluency test (category fluency and phonemic fluency) as one of a sensitive frontal function test and stroop test or tests for other cognitive domains such as digit span, Boston Naming Test (BNT), verbal memory and Mini-Mental State Examination (MMSE). Their performances for all the cognitive domain were significantly different between groups. By correlation analysis, the performance of verbal fluency test revealed significant correlation with performance of tests for another cognitive domain, especially stroop test and MMSE. This correlation was higher in mild AD patients than in moderate AD patients. Our study suggests that verbal fluency test is influenced by language and memory function, besides frontal function. Among them, verbal fluency test is most correlated with MMSE and stroop test, which is more significant in mild AD patients. As verbal fluency test seems to be correlated with general cognition in mild AD patients group, it might be used for detection of mild AD group. And early frontal dysfunction seems to be a useful marker in Alzheimer's disease.