title: A longitudinal study of neuropsychological change in individuals with Parkinson's disease.
abstract: OBJECTIVE
  Neuropsychological changes in individuals with Parkinson's disease (PD) were studied longitudinally.
  
  
  METHODS
  Sixty-nine idiopathic PD patients, with Mini-Mental State Examination (MMSE) scores falling within normal range, and 37 elderly control participants were given neuropsychological tests twice approximately two years apart.
  
  
  RESULTS
  The PD group performed poorer than the control group on Semantic Fluency, Letter Fluency, Modified Wisconsin Card Sorting Task, and Block Design at test time 1. Two years later, the PD group showed significant decline in Semantic and Letter Fluency. A subset of 12 PD patients declined in mental status by second testing (>4 MMSE points). Cox proportional-hazards models were used to see if any baseline measures were associated with relative risk of decline in mental status. In the final model, Repetition performance and Age were significantly associated with cognitive decline.
  
  
  CONCLUSIONS
  Consistent with previous studies, executive function tasks were those most susceptible to disease progression.
authors.affiliation: Department of Speech and Hearing Science, Arizona State University, Tempe, AZ 85287-0102, USA. azuma@asu.edu
authors.forename: Tamiko
authors.initials: T
authors.lastname: Azuma
authors.forename: Robyn F
authors.initials: RF
authors.lastname: Cruz
authors.forename: Kathryn A
authors.initials: KA
authors.lastname: Bayles
authors.forename: Cheryl K
authors.initials: CK
authors.lastname: Tomoeda
authors.forename: E B
authors.initials: EB
authors.lastname: Montgomery
mesh_terms: D000368:Aged; D003072:Cognition Disorders / Q000209:etiology / Q000523:psychology*; D006801:Humans; D008137:Longitudinal Studies; D009483:Neuropsychological Tests; D010300:Parkinson Disease / Q000150:complications / Q000523:psychology*; D013997:Time Factors