title: Memory and executive function impairment predict dementia in Parkinson's disease.
abstract: We analyzed the association of neuropsychological test impairment at baseline with the development of dementia in idiopathic Parkinson's disease (PD) patients. A cohort of nondemented PD patients from northern Manhattan, NY was followed annually with neurological and neuropsychological evaluations. The neuropsychological battery included tests of verbal and nonverbal memory, orientation, visuospatial ability, language, and abstract reasoning. The association of baseline neuropsychological tests scores with incident dementia was analyzed using Cox proportional hazards models. The analysis controlled for age, gender, education, duration of PD, and the total Unified Parkinson's Disease Rating Scale motor score at baseline. Forty-five out of 164 patients (27%) became demented during a mean follow-up of 3.7 +/- 2.3 years. Four neuropsychological test scores were significantly associated with incident dementia in the Cox model: total immediate recall (RR: 0.92, 95% CI: 0.87-0.97, P = 0.001) and delayed recall (RR: 0.73, 95% CI: 0.59-0.91, P = 0.005) of the Selective Reminding Test (SRT), letter fluency (RR: 0.87, 95% CI: 0.77-0.99, P = 0.03), and Identities and Oddities of the Mattis Dementia Rating Scale (RR: 0.85, 95% CI: 0.73-0.98, P = 0.03). When the analysis was performed excluding patients with a clinical dementia rating of 0.5 (questionable dementia) at baseline evaluation, total immediate recall and delayed recall were still predictive of dementia in PD. Our results indicate that impairment in verbal memory and executive function are associated with the development of dementia in patients with PD.
authors.affiliation: Gertrude H. Sergievsky Center, Columbia University, New York, NY 10032, USA.
authors.forename: Gilberto
authors.initials: G
authors.lastname: Levy
authors.forename: Diane M
authors.initials: DM
authors.lastname: Jacobs
authors.forename: Ming-Xin
authors.initials: MX
authors.lastname: Tang
authors.forename: Lucien J
authors.initials: LJ
authors.lastname: Côté
authors.forename: Elan D
authors.initials: ED
authors.lastname: Louis
authors.forename: Brenda
authors.initials: B
authors.lastname: Alfaro
authors.forename: Helen
authors.initials: H
authors.lastname: Mejia
authors.forename: Yaakov
authors.initials: Y
authors.lastname: Stern
authors.forename: Karen
authors.initials: K
authors.lastname: Marder
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000647:Amnesia / Q000175:diagnosis* / Q000523:psychology; D003072:Cognition Disorders / Q000175:diagnosis* / Q000523:psychology; D015331:Cohort Studies; D003704:Dementia / Q000175:diagnosis* / Q000523:psychology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009460:Neurologic Examination / Q000706:statistics & numerical data; D009483:Neuropsychological Tests / Q000706:statistics & numerical data; D009519:New York City; D010300:Parkinson Disease / Q000175:diagnosis* / Q000523:psychology; D011379:Prognosis; D011594:Psychometrics