title: Cognitive effects of subthalamic nucleus stimulation in Parkinson's disease: a controlled study.
abstract: BACKGROUND
  Subthalamic nucleus deep brain stimulation (STN-DBS) improves motor function in selected patients with Parkinson's disease (PD) but can be associated with variable changes in cognitive functions.
  
  
  METHODS
  We studied 21 patients selected for STN-DBS and compared 6-month clinical and neuropsychological outcomes between those who underwent surgery (n = 9) and those who voluntarily refused it (n = 12).
  
  
  RESULTS
  Motor and quality of life outcomes were markedly superior in the STN-DBS group versus controls. A wide neuropsychological battery was administered, and the whole sample showed a statistically significant worsening in phonemic verbal fluency, time to perform the Trail Making Test part B, Digit Symbol score of WAIS-III and color-naming score of the Stroop Test. In comparison to controls, a trend to a slightly worse deterioration in phonemic verbal fluency was observed in the STN-DBS patients and was significantly correlated with reductions in the L-dopa-equivalent daily dose (r = 0.850, p = 0.007).
  
  
  CONCLUSIONS
  Our study confirms the safety of STN-DBS from a cognitive standpoint; a reduction in verbal fluency at 6 months after surgery can also be related to PD progression and medication reduction.
authors.affiliation: Department of Neurology, Movement Disorders Unit, Virgen de las Nieves University Hospital, Granada, Spain.
authors.forename: Carmen
authors.initials: C
authors.lastname: Sáez-Zea
authors.forename: Francisco
authors.initials: F
authors.lastname: Escamilla-Sevilla
authors.forename: Majed J
authors.initials: MJ
authors.lastname: Katati
authors.forename: Adolfo
authors.initials: A
authors.lastname: Mínguez-Castellanos
mesh_terms: D000328:Adult; D000368:Aged; D003071:Cognition / Q000502:physiology*; D046690:Deep Brain Stimulation / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009043:Motor Activity / Q000502:physiology; D009483:Neuropsychological Tests; D010300:Parkinson Disease / Q000503:physiopathology / Q000628:therapy*; D011788:Quality of Life; D020531:Subthalamic Nucleus / Q000503:physiopathology*; D016896:Treatment Outcome