title: Subthalamic activity during diphasic dyskinesias in Parkinson's disease.
abstract: BACKGROUND
  Diphasic dyskinesias are a subtype of levodopa-induced dyskinesias that appear typically at the onset and end of levodopa antiparkinsonian action. The pathophysiology of diphasic dyskinesias is not well understood.
  
  
  METHODS
  We analyzed local field potentials recorded from the subthalamic nucleus in 7 Parkinson's disease (PD) patients who showed typical diphasic dyskinesias during postoperative recordings through a deep brain stimulation electrode. The evolution of the different oscillatory activities related to the onset and end of diphasic dyskinesias was studied by windowed fast Fourier transforms.
  
  
  RESULTS
  Typical "off"-state beta activity disappeared with the onset of diphasic dyskinesias, whereas gamma activity was absent or minimal until their end. Theta activity during diphasic dyskinesias was similar to that observed during peak-dose dyskinesias.
  
  
  CONCLUSIONS
  From a neurophysiological viewpoint, patients exhibited oscillatory activity typical of the "on" medication state during diphasic dyskinesias. The minimal presence of gamma activity during diphasic dyskinesias, however, suggests that this "on" state might be incomplete or limited to dopaminergic mechanisms affecting the lower limbs.
authors: Neurosciences Area, CIMA, University of Navarra, Pamplona, Spain. malegre@unav.es
authors: Manuel
authors: M
authors: Alegre
authors: Jon
authors: J
authors: López-Azcárate
authors: Fernando
authors: F
authors: Alonso-Frech
authors: Maria C
authors: MC
authors: Rodríguez-Oroz
authors: Miguel
authors: M
authors: Valencia
authors: Jorge
authors: J
authors: Guridi
authors: Julio
authors: J
authors: Artieda
authors: José A
authors: JA
authors: Obeso
mesh_terms: D000368:Aged; D000978:Antiparkinson Agents / Q000627:therapeutic use; D001058:Apomorphine / Q000627:therapeutic use; D015331:Cohort Studies; D046690:Deep Brain Stimulation; D018450:Disease Progression; D020820:Dyskinesias / Q000150:complications / Q000503:physiopathology*; D004567:Electrodes, Implanted; D005260:Female; D006801:Humans; D007980:Levodopa / Q000627:therapeutic use; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D019635:Neurosurgical Procedures; D010300:Parkinson Disease / Q000150:complications / Q000503:physiopathology*; D020531:Subthalamic Nucleus / Q000503:physiopathology*; D013826:Theta Rhythm
chemical_list: D000978:Antiparkinson Agents; D007980:Levodopa; D001058:Apomorphine