title: Early verbal fluency decline after STN implantation: is it a cognitive microlesion effect?
abstract: BACKGROUND
  Worsening of verbal fluency is reported after subthalamic nucleus deep brain stimulation in Parkinson's disease. It is postulated that these changes could reflect microlesion consecutive to the surgical procedure itself.
  
  
  METHODS
  We evaluated verbal fluency, in 26 patients (mean age, 57.9±8.5 years; mean disease duration, 11.4±3.5 years) both before surgery (baseline) and, after surgery respectively the third day (T3), the tenth day (T10) just after STN implantation before turning on the stimulation and at six months (T180).
  
  
  RESULTS
  Number of total words and switches was significantly reduced at T3 and T10, while average cluster size was unchanged. Repeated post-operative neuropsychological testing demonstrated reliable improvement from T3 to T180 on verbal fluency.
  
  
  CONCLUSIONS
  This study provides evidence of transient verbal fluency decline consecutive to a microlesion effect. Further studies needed to determine a putative relationship between early and long-term verbal fluency impairment.
authors: Department of Neurology, Rouen University Hospital and University of Rouen, France. romain.lefaucheur@chu-rouen.fr
authors: Romain
authors: R
authors: Lefaucheur
authors: Stéphane
authors: S
authors: Derrey
authors: Olivier
authors: O
authors: Martinaud
authors: David
authors: D
authors: Wallon
authors: Nathalie
authors: N
authors: Chastan
authors: Emmanuel
authors: E
authors: Gérardin
authors: Didier
authors: D
authors: Hannequin
authors: David
authors: D
authors: Maltête
mesh_terms: D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D003072:Cognition Disorders / Q000209:etiology*; D046690:Deep Brain Stimulation / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008037:Linguistics; D008297:Male; D008875:Middle Aged; D009043:Motor Activity / Q000502:physiology; D009483:Neuropsychological Tests; D010300:Parkinson Disease / Q000150:complications* / Q000628:therapy*; D020531:Subthalamic Nucleus / Q000502:physiology*; D014705:Verbal Behavior / Q000502:physiology*