Measures of impulsivity in Parkinson's disease decrease after DBS in the setting of stable dopamine therapy

Parkinsonism Relat Disord. 2017 Nov;44:13-17. doi: 10.1016/j.parkreldis.2017.08.006. Epub 2017 Aug 9.

Abstract

Introduction: Recent evidence suggests deep brain stimulation can alter impulse control. Our objective was to prospectively evaluate the effects of subthalamic nucleus (STN) and globus pallidus internus (GPi) deep brain stimulation on impulse control disorders (ICDs) in the setting of a conservative dopamine reduction strategy.

Methods: Patients (n = 37) undergoing de novo, unilateral STN or GPi DBS lead implantation were evaluated pre-operatively and 6-12 months post-operatively for the presence of ICDs using the Questionnaire for Impulsivity in Parkinson's disease (QUIP) and by clinical interview.

Results: Of the patients enrolled, 23 underwent electrode implantation in the globus pallidus internus and 14 were implanted in the subthalamic nucleus. Mean time to long term follow-up was 9.7 ± 2.4 months. Post-operative LEDD was not significantly lower than pre-operative LEDD (pre-op: 1238.53 ± 128.47 vs. post-op: 1178.18 ± 126.43, p = 0.2972, paired t-test). Mean QUIP scores were significantly lower at follow up compared to pre-operative baseline (1.51 ± 0.45 vs. 2.51 ± 0.58, p = 0.0447, paired t-test). Patients with ICDs pre-operatively (n = 14, 37.8%) had significant improvement in QUIP scores at follow-up (6.00 ± 0.94 vs. 2.64 ± 0.98, p = 0.0014, paired t-test). Improvement was not uniform across the cohort: 1 patient with ICD at baseline developed worsening symptoms, and 4 patients with no ICD pre-operatively developed clinically significant ICDs post-operatively.

Conclusion: When LEDD is relatively unchanged following STN or GPi DBS for PD, ICD symptoms tend toward improvement, although worsening and emergence of new ICDs can occur. In the setting of stable LEDD, these findings suggest that the intrinsic effects of DBS may play a significant role in altering impulsive behavior.

Publication types

  • Observational Study

MeSH terms

  • Aged
  • Antiparkinson Agents / therapeutic use
  • Deep Brain Stimulation / methods*
  • Disruptive, Impulse Control, and Conduct Disorders / etiology*
  • Disruptive, Impulse Control, and Conduct Disorders / therapy*
  • Female
  • Humans
  • Levodopa / therapeutic use
  • Male
  • Middle Aged
  • Parkinson Disease / psychology*
  • Parkinson Disease / therapy*
  • Surveys and Questionnaires

Substances

  • Antiparkinson Agents
  • Levodopa