title: Akineto-rigid vs. tremor syndromes in Parkinsonism.
abstract: OBJECTIVE
  Akinesia, rigidity and low-frequency rest tremor are the three cardinal motor signs of Parkinson's disease and some Parkinson's disease animal models. However, cumulative evidence supports the view that akinesia/rigidity vs. tremor reflect different pathophysiological phenomena in the basal ganglia. Here, we review the recent physiological literature correlating abnormal neural activity in the basal ganglia with Parkinson's disease clinical symptoms.
  
  
  RESULTS
  The subthalamic nucleus of Parkinson's disease patients is characterized by oscillatory activity in the beta-frequency (approximately 15 Hz) range. However, Parkinson's disease tremor is not strictly correlated with the abnormal synchronous oscillations of the basal ganglia. On the other hand, akinesia and rigidity are better correlated with the basal ganglia beta oscillations.
  
  
  CONCLUSIONS
  The abnormal basal ganglia output leads to akinesia and rigidity. Parkinson's disease tremor most likely evolves as a downstream compensatory mechanism.
authors.affiliation: Department of Physiology, The Hebrew University-Hadassah Medical School, Jerusalem, Israel.
authors.forename: Adam
authors.initials: A
authors.lastname: Zaidel
authors.forename: David
authors.initials: D
authors.lastname: Arkadir
authors.forename: Zvi
authors.initials: Z
authors.lastname: Israel
authors.forename: Hagai
authors.initials: H
authors.lastname: Bergman
mesh_terms: D000818:Animals; D001479:Basal Ganglia / Q000473:pathology / Q000503:physiopathology*; D006801:Humans; D010300:Parkinson Disease / Q000473:pathology / Q000503:physiopathology*; D014202:Tremor / Q000473:pathology / Q000503:physiopathology*