Clustering and Switching on Verbal Fluency in Vascular Dementia and Dementia of the Alzheimer's Type

Park, Jaeseol; Kang, Yeonwook; Chang, Eun Joo; Oh, Euna; Yu, Kyung Ho; Lee, Byuug Chul

ORIGINAL ARTICLE

Commun Sci Disord. 2006;11(3): 99-112.

Jaeseol Park^` , Yeonwook Kang^` , Eun Joo Chang^` , Euna Oh^` , Kyung Ho Yu^` , and Byuug Chul Lee^`

ABSTRACT

The present study was conducted to examine the deficits of clustering and switching processes on the semantic and phonemic fluencies in 57 vascular dementia(VD), 44 Dementia of the Alzheimer’s Type(DAT), and 66 normal elderly(NE). All the patients were in very mild to mild level of dementia (CDR≤1.0). The subjects were given the tests of phonemic(ㄱ, ㅇ, ㅅ) and semantic fluency(animals). The following 4 types of scores were obtained from each test: (a) total number of words generated, excluding errors; (b) mean clustering size; (c) number of switches; and (d) number of errors (repetitions and intrusion). The results found that both VD and DAT, even at the early stages of dementia, showed significantly lower performance on the verbal fluency test than the NE did. The types and timing of deficits in clustering and switching processed between two dementia groups. We discussed their implications on the differentiation between VD and DAT.