title: Frequency-dependent reciprocal modulation of verbal fluency and motor functions in subthalamic deep brain stimulation.
abstract: BACKGROUND
  High-frequency deep brain stimulation (DBS) of the subthalamic nucleus (STN) improves motor functions in those with Parkinson disease but may worsen frontal functions such as verbal fluency (VF). In contrast, low-frequency DBS leads to deterioration of motor functions. It is not known whether low-frequency STN DBS also has an effect on frontal functions.
  
  
  OBJECTIVE
  To examine whether low-frequency STN DBS in contrast to high-frequency STN DBS has a positive effect on frontal functions on the basis of VF test results.
  
  
  METHODS
  A double-blind randomized crossover experiment to compare performance in 4 VF subtests and motor performance at 10 Hz, 130 Hz, and no stimulation.
  
  
  METHODS
  University hospitals in Düsseldorf and Cologne, Germany.
  
  
  METHODS
  Twelve patients with Parkinson disease 3 months or more after bilateral electrode implantation into the STN.
  
  
  METHODS
  Mean number of words in VF at different stimulation frequencies.
  
  
  RESULTS
  The VF was significantly better at 10 Hz (48.3 words) compared with 130 Hz and showed a nonsignificant trend toward worsening at 130 Hz (42.3 words) compared with no stimulation (43.8 words). These results were consistent across all subtests.
  
  
  CONCLUSIONS
  The study provides evidence of a beneficial effect of low-frequency (10 Hz) STN DBS on VF, which may be caused by activating neural pathways projecting to the frontal cortex. In addition, the study reproduces the negative effect of therapeutic high-frequency STN DBS on VF. The study results provide evidence for a frequency-dependent modulation of cognitive circuits involving the STN.
authors.affiliation: Department of Neurology, Heinrich Heine University, Moorenstrasse 5, 40225 Düsseldorf, Germany.
authors.forename: Lars
authors.initials: L
authors.lastname: Wojtecki
authors.forename: Lars
authors.initials: L
authors.lastname: Timmermann
authors.forename: Silke
authors.initials: S
authors.lastname: Jörgens
authors.forename: Martin
authors.initials: M
authors.lastname: Südmeyer
authors.forename: Mohammad
authors.initials: M
authors.lastname: Maarouf
authors.forename: Harald
authors.initials: H
authors.lastname: Treuer
authors.forename: Joachim
authors.initials: J
authors.lastname: Gross
authors.forename: Ralph
authors.initials: R
authors.lastname: Lehrke
authors.forename: Anastasios
authors.initials: A
authors.lastname: Koulousakis
authors.forename: Jürgen
authors.initials: J
authors.lastname: Voges
authors.forename: Volker
authors.initials: V
authors.lastname: Sturm
authors.forename: Alfons
authors.initials: A
authors.lastname: Schnitzler
mesh_terms: D000368:Aged; D018592:Cross-Over Studies; D046690:Deep Brain Stimulation / Q000379:methods*; D004307:Dose-Response Relationship, Radiation; D004311:Double-Blind Method; D004558:Electric Stimulation / Q000379:methods; D005260:Female; D007839:Functional Laterality; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests / Q000706:statistics & numerical data; D010300:Parkinson Disease / Q000503:physiopathology* / Q000628:therapy*; D020531:Subthalamic Nucleus / Q000503:physiopathology / Q000528:radiation effects*; D014705:Verbal Behavior / Q000528:radiation effects*