title: Rate of cognitive decline in premotor Parkinson's disease: a prospective study (NEDICES).
abstract: Previous research has documented cognitive impairment in the early stages of Parkinson's disease (PD). It is not known when this decline starts or if decline progresses at an accelerated rate during the premotor period of the disorder. In this population-based prospective study of older people (≥65 years) from the Neurological Disorders in Central Spain (NEDICES) cohort, we compared the rates of cognitive decline in 3 groups: (1) non-PD elderly controls; (2) prevalent PD patients (those diagnosed with the disease at baseline, 1994-95); and (3) premotor PD subjects (those diagnosed with the disease at follow up, 1997-98, but not at baseline). A 37-item version of the Mini-Mental State Examination (37-MMSE) was administered in the 2 visits of the study. From 2487 participants (age, 72.8 ± 6.0 years), including 2429 controls, we recruited 21 premotor PD cases, and 37 prevalent PD cases. At baseline, the mean 37-MMSE score was 28.5 ± 4.7 in prevalent cases, 28.1 ± 4.6 in premotor cases, and 29.9 ± 5.0 in controls (P = .046). During the 3-year follow-up period, there was a significant score decline of 2.4 ± 4.6 points in prevalent cases versus 0.2 ± 4.1 points in premotor cases and 0.3 ± 4.0 points in controls (Kruskal-Wallis test, P = .03). In the NEDICES cohort, cognitive test scores of prevalent PD cases declined at a rate above and beyond that observed in premotor PD cases and in controls. The rate of cognitive decline in premotor PD and controls was similar. Our data suggest that a decline in global cognitive function does not occur in premotor PD.
authors.affiliation: Department of Neurology, University Hospital 12 de Octubre, Madrid, Spain. alvarosferro@hotmail.com
authors.forename: Álvaro
authors.initials: Á
authors.lastname: Sánchez-Ferro
authors.forename: Julián
authors.initials: J
authors.lastname: Benito-León
authors.forename: Elan D
authors.initials: ED
authors.lastname: Louis
authors.forename: Alex J
authors.initials: AJ
authors.lastname: Mitchell
authors.forename: José Antonio
authors.initials: JA
authors.lastname: Molina-Arjona
authors.forename: Rocío
authors.initials: R
authors.lastname: Trincado
authors.forename: Alberto
authors.initials: A
authors.lastname: Villarejo
authors.forename: Félix
authors.initials: F
authors.lastname: Bermejo-Pareja
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D003072:Cognition Disorders / Q000209:etiology / Q000523:psychology*; D003863:Depression / Q000150:complications / Q000188:drug therapy; D018450:Disease Progression; D004522:Educational Status; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D010300:Parkinson Disease / Q000150:complications / Q000523:psychology*; D011446:Prospective Studies; D012307:Risk Factors; D012737:Sex Factors; D013030:Spain