Impaired access to semantic memory for the cognition of geographic space in Alzheimer's disease.
This study explores the possibility to capitalize from a widely used semantic fluency test, in order to investigate aspects of topographical space representation, still poorly studied in neurodegenerative diseases. Twenty-six patients with mild Alzheimer's disease (AD) and 13 healthy control (CTR) subjects underwent neuropsychological assessment at baseline (T0) and about 2 years later (T1). The cities named during category verbal fluency test ("names of cities") were marked on a map, and the polygon perimeter obtained by joining the external points was computed. Mini-mental state examination (MMSE) score, number of cities named and perimeter length were compared between T0 and T1, both within-group and between groups. MMSE score and number of cities significantly differed between AD and CTR both at T0 and at T1; perimeter length differed significantly only at T1. Between T0 and T1, all the three parameters significantly decreased in AD, while they were substantially unchanged in CTR. Besides a reduction of semantic verbal fluency, there seems to be a 'restriction' of mental geographic space representation already in mild AD. These findings should be confirmed and exploited by further ad hoc investigations.
Clinical Neurophysiology (DiNOG, DipTeC), University of Genoa, S. Martino University Hospital, Viale Benedetto XV, 6, I-16132 Genoa, Italy. debora.mazzei@libero.it
Debora
D
Mazzei
Andrea
A
Brugnolo
Barbara
B
Dessi
Nicola
N
Girtler
Francesco
F
Famà
Elisa
E
Rizza
Flavio
F
Nobili
Guido
G
Rodriguez
D000368:Aged; D000544:Alzheimer Disease / Q000453:epidemiology*; D001931:Brain Mapping; D005260:Female; D005843:Geography; D006801:Humans; D008297:Male; D008569:Memory Disorders / Q000175:diagnosis* / Q000453:epidemiology; D008875:Middle Aged; D009483:Neuropsychological Tests; D012660:Semantics; D012720:Severity of Illness Index