title: High beta activity in the subthalamic nucleus and freezing of gait in Parkinson's disease.
abstract: OBJECTIVE
  Oscillatory activity in the beta band is increased in the subthalamic nucleus (STN) of Parkinson's disease (PD) patients. Rigidity and bradykinesia are associated with the low-beta component (13-20Hz) but the neurophysiological correlate of freezing of gait in PD has not been ascertained.
  
  
  METHODS
  We evaluated the power and coherence of the low- and high-beta bands in the STN and cortex (EEG) of PD patients with (p-FOG) (n=14) or without freezing of gait (n-FOG) (n=8) in whom electrodes for chronic stimulation in the STN had been implanted for treatment with deep brain stimulation.
  
  
  RESULTS
  p-FOG patients showed higher power in the high-beta band (F=11.6, p=0.002) that was significantly reduced after l-dopa administration along with suppression of FOG (F=4.6, p=0.042). High-beta cortico-STN coherence was maximal for midline cortical EEG electrodes, whereas the low-beta band was maximal for lateral electrodes (χ(2)=20.60, p<0.0001).
  
  
  CONCLUSIONS
  The association between freezing of gait, high-beta STN oscillations and cortico-STN coherence suggests that this oscillatory activity might interfere in the frontal cortex-basal ganglia networks, thereby participating in the pathophysiology of FOG in PD.
authors.affiliation: Neurosciences Area, CIMA, University of Navarra, Av Pio XII 55, 31008 Pamplona, Spain. Electronic address: jtoledo@mail.med.upenn.edu.
authors.forename: Jon B
authors.initials: JB
authors.lastname: Toledo
authors.affiliation: Neurosciences Area, CIMA, University of Navarra, Av Pio XII 55, 31008 Pamplona, Spain. Electronic address: jlopez.6@alumni.unav.es.
authors.forename: Jon
authors.initials: J
authors.lastname: López-Azcárate
authors.affiliation: Neurosciences Area, CIMA, University of Navarra, Av Pio XII 55, 31008 Pamplona, Spain; Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Spain. Electronic address: dagarciagarcia@gmail.com.
authors.forename: David
authors.initials: D
authors.lastname: Garcia-Garcia
authors.affiliation: Neurology and Neurosurgery, Clinica Universidad de Navarra, Av. Pio XII 36, Pamplona, Spain. Electronic address: jguridi@unav.es.
authors.forename: Jorge
authors.initials: J
authors.lastname: Guridi
authors.affiliation: Neurosciences Area, CIMA, University of Navarra, Av Pio XII 55, 31008 Pamplona, Spain. Electronic address: mvustarroz@unav.es.
authors.forename: Miguel
authors.initials: M
authors.lastname: Valencia
authors.affiliation: Neurosciences Area, CIMA, University of Navarra, Av Pio XII 55, 31008 Pamplona, Spain; Neurology and Neurosurgery, Clinica Universidad de Navarra, Av. Pio XII 36, Pamplona, Spain. Electronic address: jartieda@unav.es.
authors.forename: Julio
authors.initials: J
authors.lastname: Artieda
authors.affiliation: Neurosciences Area, CIMA, University of Navarra, Av Pio XII 55, 31008 Pamplona, Spain; Neurology and Neurosurgery, Clinica Universidad de Navarra, Av. Pio XII 36, Pamplona, Spain; Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Spain. Electronic address: jobeso52@gmail.com.
authors.forename: Jose
authors.initials: J
authors.lastname: Obeso
authors.affiliation: Neurosciences Area, CIMA, University of Navarra, Av Pio XII 55, 31008 Pamplona, Spain; Neurology and Neurosurgery, Clinica Universidad de Navarra, Av. Pio XII 36, Pamplona, Spain. Electronic address: malegre@unav.es.
authors.forename: Manuel
authors.initials: M
authors.lastname: Alegre
authors.affiliation: Neurosciences Area, CIMA, University of Navarra, Av Pio XII 55, 31008 Pamplona, Spain; Neurology and Neurosurgery, Clinica Universidad de Navarra, Av. Pio XII 36, Pamplona, Spain; Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Spain. Electronic address: maria.rodriguezoroz@biodonostia.org.
authors.forename: Maria
authors.initials: M
authors.lastname: Rodriguez-Oroz
mesh_terms: D000978:Antiparkinson Agents / Q000627:therapeutic use; D001611:Beta Rhythm / Q000187:drug effects / Q000502:physiology*; D002540:Cerebral Cortex / Q000187:drug effects / Q000503:physiopathology; D046690:Deep Brain Stimulation; D004569:Electroencephalography; D005260:Female; D020235:Gait Apraxia / Q000188:drug therapy / Q000209:etiology* / Q000503:physiopathology* / Q000628:therapy; D006801:Humans; D058542:Implantable Neurostimulators; D007980:Levodopa / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D009434:Neural Pathways / Q000187:drug effects / Q000503:physiopathology; D010300:Parkinson Disease / Q000150:complications* / Q000188:drug therapy / Q000503:physiopathology* / Q000628:therapy; D020531:Subthalamic Nucleus / Q000187:drug effects / Q000503:physiopathology*
chemical_list: D000978:Antiparkinson Agents; D007980:Levodopa
keywords: Beta activity; Freezing of gait; Oscillatory activity; Parkinson's disease; Subthalamic nucleus