[Everyday memory impairment in Parkinson's disease].

Memory impairment has been frequently reported in patients with Parkinson's disease. The traditional tests used in previous studies, however, failed to sufficiently reflect memory performance in everyday life. To investigate everyday memory in patients with Parkinson's disease, an objective test of everyday memory, the Rivermead Behavioural Memory Test (RBMT), and an everyday memory questionnaire were administered to 26 parkinsonian patients and 26 age-matched normal controls. The parkinsonian patients scored significantly lower on the RBMT than the controls (p < 0.01). Moreover, the parkinsonian patients performed especially poorly on subtests related to prospective memory (p < 0.05). These subtests are thought to be sensitive to frontal lobe function. On the everyday memory questionnaire, the parkinsonian patients estimated their own everyday memory to be significantly worse than did the controls (p < 0.01). Further, the patients estimated their everyday memory to be especially poor in comparison with the controls on the sub-items related to recency memory (p < 0.05), source memory (p < 0.01), action slip (p < 0.01), and tip-of-the-tongue phenomenon (p < 0.05). In the patient group, the RBMT score correlated significantly with the scores on the Wisconsin Card Sorting Test (p < 0.05) and tests of verbal fluency (p < 0.05). These results indicate that everyday memory is impaired in patients with Parkinson's disease, and that this impairment is partly related to frontal lobe dysfunction.