title: Cognitive correlates of visual hallucinations in non-demented Parkinson's disease patients.
abstract: BACKGROUND
  Visual hallucinations (VH) in Parkinson's disease (PD) are associated with PD dementia and have been related to cognitive impairments in non-demented PD patients. Reports on the specific cognitive domains affected are conflicting. The aim of the present study was to investigate the presence of specific cognitive impairments in non-demented PD patients with VH, compared to those without VH.
  
  
  METHODS
  We compared the clinical characteristics and neuropsychological test scores of 31 non-demented PD patients with VH with those of 31 PD patients without VH that were carefully matched for sex, age, disease duration and educational level. Several non-motor symptoms, including depression, anxiety and sleep disturbances, were also taken into account, as these may influence cognitive performance.
  
  
  RESULTS
  The PD with VH group performed significantly worse on the Trail Making Test part A (p = 0.01) and the Rey Auditory Verbal Learning Test, immediate recall (p = 0.01). In addition, PD patients with VH were more anxious, more depressed and reported more sleep disturbances. Verbal learning scores were not associated with levels of anxiety, depression or sleep disruption, whereas worse Trail Making Test A performance was associated with concomitant sleep disturbances.
  
  
  CONCLUSIONS
  In non-demented PD patients, the presence of VH is associated with a cognitive profile characterized by impairments in verbal learning and probably attention. Since these cognitive functions are believed to be non-dopaminergic mediated functions, the present results support the hypothesis that multiple neurotransmitter systems, other than dopamine, contribute to the pathophysiology of VH in PD.
authors.affiliation: Department of Neurology, Neuroscience Campus Amsterdam, VU University Medical Center, Amsterdam, The Netherlands. d.hepp@vumc.nl
authors.forename: D H
authors.initials: DH
authors.lastname: Hepp
authors.forename: C C
authors.initials: CC
authors.lastname: da Hora
authors.forename: T
authors.initials: T
authors.lastname: Koene
authors.forename: B M
authors.initials: BM
authors.lastname: Uitdehaag
authors.forename: O A
authors.initials: OA
authors.lastname: van den Heuvel
authors.forename: M
authors.initials: M
authors.lastname: Klein
authors.forename: W D
authors.initials: WD
authors.lastname: van de Berg
authors.forename: H W
authors.initials: HW
authors.lastname: Berendse
authors.forename: E M
authors.initials: EM
authors.lastname: Foncke
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001288:Attention / Q000502:physiology; D003072:Cognition Disorders / Q000209:etiology / Q000503:physiopathology*; D003704:Dementia / Q000503:physiopathology; D005260:Female; D006212:Hallucinations / Q000209:etiology / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D010300:Parkinson Disease / Q000150:complications / Q000503:physiopathology* / Q000523:psychology
keywords: Cognition; Neuropsychiatry; Non-motor symptoms; Parkinson's disease; Visual hallucinations