title: Intraoperative dopamine release during globus pallidus internus stimulation in Parkinson's disease.
abstract: BACKGROUND
  It is still unclear whether dopamine (DA) levels correlate with Parkinson's disease (PD) severity or play a role in the mechanisms of high-frequency stimulation (HFS).
  
  
  METHODS
  We have used microdialysis to record pallidal DA in 5 patients with PD undergoing microelectrode-guided pallidotomy.
  
  
  RESULTS
  We found that patients with more severe disease and, consequently, lower pallidal DA did poorly after pallidal lesions. In the operating room, 4 of 5 patients had a significant increase in DA levels during HFS (600%, on average). To test the hypothesis that DA was important for the effects of stimulation, we correlated the amelioration in rigidity observed in the operating room with pallidal DA release. Though rigidity was 56% better during stimulation, no correlation was found between such an improvement and DA release.
  
  
  CONCLUSIONS
  These findings suggest that additional mechanisms not directly dependent on pallidal DA release may be involved in the clinical effects of HFS of the globus pallidus internus.
authors.affiliation: Laboratory of Neuromodulation and Experimental Pain, Hospital Sirio-Libanes, São Paulo, Brazil; University of São Paulo and Institute of Neuroscience and Behavior (INeC), Campus USP, Ribeirao Preto, Brazil; Department of Neurology, Division of Functional Neurosurgery; Institute of Psychiatry, University of São Paulo School of Medicine, São Paulo, Brazil; Department of Surgery, Discipline of Surgical Technique, School of Medicine, University of São Paulo, LIM 26 HC-FMUSP, São Paulo, Brazil.
authors.forename: Raquel C R
authors.initials: RC
authors.lastname: Martinez
authors.forename: Clement
authors.initials: C
authors.lastname: Hamani
authors.forename: Milene Cristina
authors.initials: MC
authors.lastname: de Carvalho
authors.forename: Amanda Ribeiro
authors.initials: AR
authors.lastname: de Oliveira
authors.forename: Eduardo
authors.initials: E
authors.lastname: Alho
authors.forename: Jessie
authors.initials: J
authors.lastname: Navarro
authors.forename: Maria Gabriela
authors.initials: MG
authors.lastname: Dos Santos Ghilardi
authors.forename: Edson
authors.initials: E
authors.lastname: Bor-Seng-Shu
authors.forename: Helmut
authors.initials: H
authors.lastname: Heinsen
authors.forename: José Pinhata
authors.initials: JP
authors.lastname: Otoch
authors.forename: Marcus Lira
authors.initials: ML
authors.lastname: Brandão
authors.forename: Egberto Reis
authors.initials: ER
authors.lastname: Barbosa
authors.forename: Manoel Jacobsen
authors.initials: MJ
authors.lastname: Teixeira
authors.forename: Erich Talamoni
authors.initials: ET
authors.lastname: Fonoff
mesh_terms: D000368:Aged; D001703:Biophysics; D002853:Chromatography, Liquid; D046690:Deep Brain Stimulation / Q000379:methods*; D004298:Dopamine / Q000378:metabolism*; D005260:Female; D005917:Globus Pallidus / Q000502:physiology*; D006801:Humans; D007432:Intraoperative Period; D008297:Male; D017551:Microdialysis; D008875:Middle Aged; D010300:Parkinson Disease / Q000378:metabolism / Q000628:therapy*; D012720:Severity of Illness Index; D013223:Statistics as Topic; D013997:Time Factors
chemical_list: D004298:Dopamine
keywords: Parkinson's disease; deep brain stimulation; dopamine; microdialysis; motor symptoms