title: CERAD test performance and cognitive impairment in Parkinson's disease.
abstract: OBJECTIVE
  Many patients with Parkinson's disease (PD) develop mild cognitive impairment (PD-MCI) and dementia (PDD). The Consortium to Establish a Registry for Alzheimer's Disease (CERAD) neurocognitive test battery was originally developed to identify early Alzheimer's disease, but it has become a widely used screening instrument also for other types of dementia. The aim of the study was to examine differences in CERAD test performances between cognitively intact and impaired PD patients.
  
  
  METHODS
  Eighty-eight PD patients participating in a rehabilitation course were studied. The Clinical Dementia Rating (CDR) was used to assess cognitive impairment. Sixty-six patients were cognitively intact and 22 had cognitive impairment (≥1 in two or more domains or a sum of boxes score of ≥3). The Finnish CERAD test battery was used to measure cognitive functions in seven different domains (language functions, verbal learning, visuospatial functions, delayed recall, memory consolidation, recognition memory, and executive functions).
  
  
  RESULTS
  There were significant differences between the cognitively intact and impaired patients in six CERAD subtests (wordlist learning sum, wordlist delayed recall, constructional praxis recall, clock drawing, verbal fluency and constructional praxis copy) when controlling for covariates (disease duration, motor symptoms, age, and education). No differences were observed in memory consolidation scores.
  
  
  CONCLUSIONS
  The results indicate that mild cognitive impairment in PD is related to deficits in memory, executive functions, and visuospatial functions. The memory deficit is non-amnestic and does not entail accelerated forgetting. CERAD shows promise in identifying PD patients with cognitive impairment and increased risk of dementia.
authors.affiliation: Department of Psychology and Logopedics, Abo Akademi University, Turku, Finland.
authors.forename: M
authors.initials: M
authors.lastname: Karrasch
authors.forename: S
authors.initials: S
authors.lastname: Laatu
authors.forename: K
authors.initials: K
authors.lastname: Martikainen
authors.forename: R
authors.initials: R
authors.lastname: Marttila
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003072:Cognition Disorders / Q000175:diagnosis* / Q000209:etiology*; D056344:Executive Function; D005260:Female; D006801:Humans; D008297:Male; D008568:Memory; D008875:Middle Aged; D009483:Neuropsychological Tests; D010300:Parkinson Disease / Q000150:complications*; D014706:Verbal Learning / Q000502:physiology; D014796:Visual Perception
keywords: CERAD; Clinical dementia rating; Parkinson's disease; cognitive functions; dementia; mild cognitive impairment