title: Correlation of EEG slowing with cognitive domains in nondemented patients with Parkinson's disease.
abstract: BACKGROUND
  Cognitive deficits in Parkinson's disease (PD) are heterogeneous and can be classified into cognitive domains. Quantitative EEG is related to and predictive of cognitive status in PD. In this cross-sectional study, the relationship of cognitive domains and EEG slowing in PD patients without dementia is investigated.
  
  
  METHODS
  A total of 48 patients with idiopathic PD were neuropsychologically tested. Cognitive domain scores were calculated combining Z-scores of test variables. Slowing of EEG was measured with median EEG frequency. Linear regression was used for correlational analyses and to control for confounding factors.
  
  
  RESULTS
  EEG median frequency was significantly correlated to cognitive performance in most domains (episodic long-term memory, rho = 0.54; overall cognitive score, rho = 0.47; fluency, rho = 0.39; attention, rho = 0.37; executive function, rho = 0.34), but not to visuospatial functions and working memory.
  
  
  CONCLUSIONS
  Global EEG slowing is a marker for overall cognitive impairment in PD and correlates with impairment in the domains attention, executive function, verbal fluency, and episodic long-term memory, but not with working memory and visuospatial functions. These disparate effects warrant further investigations.
authors.affiliation: Department of Neurology, University Hospital Basel, Basel, Switzerland.
authors.forename: Ronan
authors.initials: R
authors.lastname: Zimmermann
authors.forename: Ute
authors.initials: U
authors.lastname: Gschwandtner
authors.forename: Florian
authors.initials: F
authors.lastname: Hatz
authors.forename: Christian
authors.initials: C
authors.lastname: Schindler
authors.forename: Habib
authors.initials: H
authors.lastname: Bousleiman
authors.forename: Shaheen
authors.initials: S
authors.lastname: Ahmed
authors.forename: Martin
authors.initials: M
authors.lastname: Hardmeier
authors.forename: Antonia
authors.initials: A
authors.lastname: Meyer
authors.forename: Pasquale
authors.initials: P
authors.lastname: Calabrese
authors.forename: Peter
authors.initials: P
authors.lastname: Fuhr
mesh_terms: D000368:Aged; D003071:Cognition / Q000145:classification; D003072:Cognition Disorders / Q000175:diagnosis / Q000209:etiology*; D060825:Cognitive Dysfunction / Q000175:diagnosis / Q000209:etiology*; D003430:Cross-Sectional Studies; D004569:Electroencephalography; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D010300:Parkinson Disease / Q000523:psychology*