title: Neuropsychological effects of deep brain stimulation in subjects with early stage Parkinson's disease in a randomized clinical trial.
abstract: BACKGROUND
  Deep brain stimulation (DBS) is an effective treatment for patients with advanced Parkinson's disease (PD) and motor symptom complications. Recently, attention has been focused on whether offering DBS earlier in the course of PD is beneficial.
  
  
  OBJECTIVE
  The purpose of this study was to determine the effects of DBS on neuropsychological functioning in subjects with early stage PD.
  
  
  METHODS
  Thirty subjects with early PD (Hoehn & Yahr Stage II off medication) were randomized to optimal drug therapy (ODT) (n = 15) or bilateral subthalamic nucleus (STN) DBS+ODT (n = 15) after completing an expanded informed consent process specially designed for the study and administered by a medical ethicist and the study team. Comprehensive neuropsychological testing was completed in the treatment-withdrawn state at baseline and at 12 month and 24 month follow-ups.
  
  
  RESULTS
  Two serious adverse events occurred in the DBS+ODT group. One subject experienced a stroke and another developed infected hardware that contributed to specific declines in cognitive functioning. However, compared to the ODT group, the remaining subjects in the DBS+ODT group exhibited modest reductions on a few measures of attention, executive function, and word fluency at 12 months. These differences were largely diminished at 24 months, especially when those with the adverse events were excluded.
  
  
  CONCLUSIONS
  The results of this trial provide novel data regarding the effects of DBS on cognitive function in early PD. We believe that the findings and insights from this trial can help guide the safety analysis and risk-benefit evaluations in future discussions of DBS in early stage PD.
authors.affiliation: Department of Psychiatry, Vanderbilt University Medical Center, Nashville, TN, USA.
authors.forename: Michael G
authors.initials: MG
authors.lastname: Tramontana
authors.affiliation: Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, USA.
authors.forename: Anna L
authors.initials: AL
authors.lastname: Molinari
authors.affiliation: Department of Neurosurgery, Vanderbilt University Medical Center, Nashville, TN, USA.
authors.forename: Peter E
authors.initials: PE
authors.lastname: Konrad
authors.affiliation: Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, USA.
authors.forename: Thomas L
authors.initials: TL
authors.lastname: Davis
authors.affiliation: Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, USA.
authors.forename: Scott A
authors.initials: SA
authors.lastname: Wylie
authors.affiliation: Department of Neurosurgery, Vanderbilt University Medical Center, Nashville, TN, USA.
authors.forename: Joseph S
authors.initials: JS
authors.lastname: Neimat
authors.affiliation: School of Medicine, Vanderbilt University, Nashville, TN, USA.
authors.forename: Alexandra T
authors.initials: AT
authors.lastname: May
authors.affiliation: Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, USA.
authors.forename: Fenna T
authors.initials: FT
authors.lastname: Phibbs
authors.affiliation: Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, USA.
authors.forename: Peter
authors.initials: P
authors.lastname: Hedera
authors.affiliation: Department of Neurology, Loyola University Chicago, Maywood, IL, USA.
authors.forename: Chandler E
authors.initials: CE
authors.lastname: Gill
authors.affiliation: Department of Psychiatry, Vanderbilt University Medical Center, Nashville, TN, USA.
authors.forename: Ronald M
authors.initials: RM
authors.lastname: Salomon
authors.affiliation: Department of Biostatistics, Vanderbilt University Medical Center, Nashville, TN, USA.
authors.forename: Lily
authors.initials: L
authors.lastname: Wang
authors.affiliation: Department of Biostatistics, Vanderbilt University Medical Center, Nashville, TN, USA.
authors.forename: Yanna
authors.initials: Y
authors.lastname: Song
authors.affiliation: Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, USA.
authors.forename: David
authors.initials: D
authors.lastname: Charles
mesh_terms: D000368:Aged; D000978:Antiparkinson Agents / Q000627:therapeutic use; D003072:Cognition Disorders / Q000209:etiology* / Q000628:therapy*; D046690:Deep Brain Stimulation / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D010300:Parkinson Disease / Q000150:complications* / Q000628:therapy; D012720:Severity of Illness Index; D020531:Subthalamic Nucleus / Q000187:drug effects / Q000502:physiology*; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D000978:Antiparkinson Agents
keywords: Parkinson's disease; deep brain stimulation; neuropsychological tests; subthalamic nucleus