title: Saccade-related potentials recorded from human subthalamic nucleus.
abstract: OBJECTIVE
  To investigate an ocular motor role for the STN in Parkinson's disease (PD) patients.
  
  
  METHODS
  Potentials were recorded from deep brain stimulation (DBS) electrodes implanted in the vicinity of STN in five PD patients, while patients simultaneously performed visually cued saccades, self-paced saccades and in two patients self-paced wrist extensions.
  
  
  RESULTS
  Premovement potentials related to visually cued saccades were found in 4/5 patients and 56% (5/9) of potentials showed phase reversal indicating a local generator. Onsets of these potentials began closer to saccade initiation from STN contacts (0.88+/-0.30s) than thalamic ones (1.39+/-0.28 s). Self-paced saccade-related potentials were found in 4/4 patients. Self-paced saccade potential onsets (1.82+/-0.88 s) were not different from self-paced wrist extension onsets (1.27+/-0.98 s), suggesting a non-specific mechanism could be responsible for both potentials. 50% (3/6) of potentials to self-paced saccades and 66% (2/3) of potentials to self-paced wrist extensions showed phase reversal. Potentials could be found either ipsilaterally or contralaterally with respect to saccade direction.
  
  
  CONCLUSIONS
  These subcortical premovement potentials to saccades are similar to Bereitschaftspotentials and contingent negative variations to limb movements recorded in cortical and subcortical regions.
  
  
  CONCLUSIONS
  These studies further support a role of STN in ocular motor control and suggest a common mechanism of motor preparation for both eye and limb movements in the basal ganglia.
authors.affiliation: Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ont., Canada.
authors.forename: Adrian P
authors.initials: AP
authors.lastname: Fawcett
authors.forename: Daniel
authors.initials: D
authors.lastname: Cunic
authors.forename: Clement
authors.initials: C
authors.lastname: Hamani
authors.forename: Mojgan
authors.initials: M
authors.lastname: Hodaie
authors.forename: Andres M
authors.initials: AM
authors.lastname: Lozano
authors.forename: Robert
authors.initials: R
authors.lastname: Chen
authors.forename: William D
authors.initials: WD
authors.lastname: Hutchison
mesh_terms: D000328:Adult; D000368:Aged; D003463:Cues; D046690:Deep Brain Stimulation / Q000379:methods; D005074:Evoked Potentials, Visual / Q000502:physiology*; D005260:Female; D007839:Functional Laterality; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000473:pathology; D010775:Photic Stimulation / Q000379:methods; D011597:Psychomotor Performance / Q000502:physiology; D011930:Reaction Time; D012438:Saccades / Q000502:physiology*; D020531:Subthalamic Nucleus / Q000503:physiopathology*; D014953:Wrist / Q000294:innervation