title: Deep brain stimulation does not change neurovascular coupling in non-motor visual cortex: an autonomic and visual evoked blood flow velocity response study.
abstract: OBJECTIVE
  In Parkinson's disease (PD) subthalamic nucleus deep brain stimulation (STN-DBS) improves motor function. Also an effect on the neurovascular coupling in motor cortex was reported due to a parallel activation of a subthalamic vasodilator area (SVA). To address this issue further we analysed neurovascular coupling in a non-motor area.
  
  
  METHODS
  Twenty PD patients selected for bilateral STN-DBS were investigated with functional transcranial Doppler (f-TCD) before and after surgery. Hemodynamic responses to visual stimulation were registered in left posterior cerebral artery (PCA) and analysed with a control-system approach (parameters gain, rate time, attenuation and natural frequency). To exclude autonomic effects of STN-DBS, we also addressed spectrum analysis of heart rate and of systolic arterial blood pressure variability, and baroreceptor gain. Findings in the PD group were compared with healthy age-matched controls.
  
  
  RESULTS
  PD patients showed no neurovascular coupling changes in PCA territory, compared to controls, and STN-DBS changed neither blood flow regulatory parameters nor autonomic function.
  
  
  CONCLUSIONS
  Improvement of vasoregulation in some motor cortical areas after STN-DBS might be related to an improved neuronal functional rather than indicating an effect on the neurovascular coupling or autonomic function.
authors.affiliation: Department of Neurology, Hospital São João and Faculty of Medicine of University of Porto, Alameda Professor Hernani Monteiro, 4202-451 Porto, Portugal. elsaazevedo@netcabo.pt
authors.forename: Elsa
authors.initials: E
authors.lastname: Azevedo
authors.forename: Rosa
authors.initials: R
authors.lastname: Santos
authors.forename: João
authors.initials: J
authors.lastname: Freitas
authors.forename: Maria-José
authors.initials: MJ
authors.lastname: Rosas
authors.forename: Miguel
authors.initials: M
authors.lastname: Gago
authors.forename: Carolina
authors.initials: C
authors.lastname: Garrett
authors.forename: Bernhard
authors.initials: B
authors.lastname: Rosengarten
mesh_terms: D000368:Aged; D001341:Autonomic Nervous System / Q000503:physiopathology*; D001783:Blood Flow Velocity / Q000502:physiology; D001794:Blood Pressure / Q000502:physiology; D002536:Cerebral Arteries / Q000503:physiopathology; D002560:Cerebrovascular Circulation / Q000502:physiology*; D046690:Deep Brain Stimulation; D004569:Electroencephalography; D005074:Evoked Potentials, Visual / Q000502:physiology*; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology / Q000628:therapy; D010775:Photic Stimulation / Q000379:methods; D011569:Psychiatric Status Rating Scales; D017585:Ultrasonography, Doppler, Transcranial / Q000379:methods; D014793:Visual Cortex / Q000000981:diagnostic imaging / Q000503:physiopathology*