title: Electrophysiological characteristics of limbic and motor globus pallidus internus (GPI) neurons in two cases of Lesch-Nyhan syndrome.
abstract: OBJECTIVE
  Lesch-Nyhan syndrome is a rare and debilitating condition characterized by dystonia and self-mutilating behavior. In order to shed light on the pathophysiology of dystonia, we report the pallidal electrophysiological activity recorded in two patients during deep brain stimulation surgery (DBS).
  
  
  METHODS
  Microrecordings were performed on 162 neurons along four tracks aimed at the right and left anterior (limbic) and posterior (motor) globus pallidus internus (GPI).
  
  
  RESULTS
  Regardless of the anesthetic agent used (propofol or sevoflurane), both patients showed similar neurons firing rates in the four regions studied, namely the limbic and motor portions of the globus pallidus externus (GPE) or GPI. In both patients, firing rates were similar in the GPE (12.2+/-1.8 Hz, N=38) and GPI (13.2+/-1.0 Hz, N=83) portions of the limbic track, while the motor GPE fired at a higher frequency (23.8+/-2.7 Hz, N=18) than the motor GPI (12.5+/-1.4 Hz, N=23).
  
  
  CONCLUSIONS
  These results demonstrate that light propofol or sevoflurane anesthesia influences pallidal activity in a similar way. Electrophysiological recordings suggest that Lesch-Nyhan syndrome might be characterized by analogous firing frequencies in the limbic GPE and GPI while motor GPE would tend to fire at higher rate than the motor GPI. It is therefore tempting to suggest that the symptoms that are observed in Lesch-Nyhan syndrome might result from motor GPI inhibition.
  
  
  CONCLUSIONS
  This observation may confirm the Albin and Delong's model of the basal nuclei in hypokinetic and hyperkinetic disorders.
authors.affiliation: UNN-NS BH 13, CHUV, 1011 Lausanne, Switzerland. Etienne.Pralong@hospvd.ch
authors.forename: E
authors.initials: E
authors.lastname: Pralong
authors.forename: C
authors.initials: C
authors.lastname: Pollo
authors.forename: P
authors.initials: P
authors.lastname: Coubes
authors.forename: J
authors.initials: J
authors.lastname: Bloch
authors.forename: E
authors.initials: E
authors.lastname: Roulet
authors.forename: M-H
authors.initials: MH
authors.lastname: Tétreault
authors.forename: D
authors.initials: D
authors.lastname: Debatisse
authors.forename: J-G
authors.initials: JG
authors.lastname: Villemure
mesh_terms: D002648:Child; D004599:Electric Stimulation Therapy; D004594:Electrophysiology / Q000379:methods; D005917:Globus Pallidus / Q000503:physiopathology*; D006801:Humans; D007041:Hypoxanthine Phosphoribosyltransferase / Q000172:deficiency; D007926:Lesch-Nyhan Syndrome / Q000503:physiopathology*; D008032:Limbic System / Q000503:physiopathology*; D009046:Motor Neurons / Q000502:physiology*; D012890:Sleep / Q000502:physiology
chemical_list: D007041:Hypoxanthine Phosphoribosyltransferase