title: Pre-operative obesity may influence subthalamic stimulation outcome in Parkinson's disease.
abstract: BACKGROUND
  Pre-operative predictive factors for optimal post-operative effect of subthalamic nucleus (STN) stimulation in Parkinson's disease (PD) have been previously reported. No study has explicitly assessed the link between excess pre-operative body weight and STN stimulation outcome.
  
  
  METHODS
  We retrospectively compared STN stimulation outcomes of 36 PD patients with excess pre-operative body weight (group 1) and 36 matched normal-weight pre-operative (group 2) PD patients. We focused on the post-operative outcomes in the sub-group of 12 obese (group 3) PD patients.
  
  
  RESULTS
  The post-operative motor improvement and the reduction of severity of levodopa-related complications were not statistically different between groups 1 and 2 (P>0.05). In the obese group (group 3), the axial sub-score significantly improved by 29.8% in the on-drug/on-stimulation conditions whereas the improvement was not significant in the off-drug/on-stimulation condition (22.4%, P=0.20). The post-operative Mattis Dementia Rating Score was significantly reduced in group 1 and group 3.
  
  
  CONCLUSIONS
  We considered that the post-operative axial impairment observed in the obese PD patients might be essentially consecutive to disease progression and/or post-operative DBS consequences, i.e. surgical procedure or electrical stimulation itself. Moreover, it could be argued that musculoskeletal disorders associated with obesity were responsible for the incomplete efficacy of STN stimulation on axial sub-scores, by increasing gait and balance impairment.
  
  
  CONCLUSIONS
  Pre-operative obesity may be regarded as a predictive clinical factor of axial and cognitive impairment after STN-DBS.
authors.affiliation: Department of Neurology, Rouen University Hospital, University of Rouen, France.
authors.forename: Audrey
authors.initials: A
authors.lastname: Rouillé
authors.affiliation: Department of Neurosurgery, Rouen University Hospital, University of Rouen, France.
authors.forename: Stéphane
authors.initials: S
authors.lastname: Derrey
authors.affiliation: Department of Neurology, Rouen University Hospital, University of Rouen, France. Electronic address: romain.lefaucheur@chu-rouen.fr.
authors.forename: Romain
authors.initials: R
authors.lastname: Lefaucheur
authors.affiliation: Department of Neurology, Rouen University Hospital, University of Rouen, France.
authors.forename: Alaina
authors.initials: A
authors.lastname: Borden
authors.affiliation: Department of Neurology, Rouen University Hospital, University of Rouen, France.
authors.forename: Damien
authors.initials: D
authors.lastname: Fetter
authors.affiliation: Department of Neurology, Rouen University Hospital, University of Rouen, France.
authors.forename: Maryvonne
authors.initials: M
authors.lastname: Jan
authors.affiliation: Department of Neurology, Rouen University Hospital, University of Rouen, France; INSERM Unit, 1073 Rouen, France.
authors.forename: David
authors.initials: D
authors.lastname: Maltête
mesh_terms: D000328:Adult; D001835:Body Weight; D016022:Case-Control Studies; D046690:Deep Brain Stimulation / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000503:physiopathology*; D010300:Parkinson Disease / Q000628:therapy*; D012189:Retrospective Studies; D012720:Severity of Illness Index; D020531:Subthalamic Nucleus / Q000502:physiology*; D016896:Treatment Outcome
keywords: BMI; Body mass index; Cognitive impairment; Deep brain stimulation; Obesity; Parkinson's disease; Subthalamic nucleus