Steady or not following thalamic deep brain stimulation for essential tremor

J Neurol. 2011 Sep;258(9):1643-8. doi: 10.1007/s00415-011-5986-0. Epub 2011 Mar 27.

Abstract

Deep brain stimulation (DBS) has become an important option for medication-refractory essential tremor (ET), but may contribute to worsened gait and falling. This study evaluates impaired gait in a cohort of patients treated with DBS with a retrospective review of ET patients before and after DBS implantation. Factors examined included: age, duration of symptoms, pre-morbid gait difficulties/falls, Fahn-Tolosa-Marin tremorrating scale (TRS) scores at baseline, 6 months post-unilateral DBS implantation, and 6 or 12 months post-bilateral implantation. All implantations targeted the nucleus ventralis intermediate (Vim). Thirty-eight patients (25 males, 13 females) were included. Twenty-five patients (65.8%) underwent unilateral DBS implantation and 13 (34.2%) bilateral. The mean age at surgery was 67.1 years ± 11.4 (range 34-81). The mean disease duration was 31 years ± 18.3 (range 6-67). Fifty-eight percent of patients had worsened gait post-operatively. Seventy percent of patients with unilateral Vim DBS experienced gait worsening while 55% of bilateral DBS patients experienced gait worsening. Patients with worsened gait post-DBS had higher baseline pre-operative TRS scores than those without worsened gait (43.1 points ± 8.4 vs. 33.1 points ± 10.1, p = 0.002) (odds ratio 2.5, p = 0.02). Gait/balance may worsen following DBS for medication refractory ET. Higher baseline TRS score may factor into these issues, although a larger prospective study will be required with a control population. The larger percentage of difficulties observed in unilateral versus bilateral cases likely reflected the bias not to proceed to second-sided surgery if gait/balance problems were encountered.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Cohort Studies
  • Deep Brain Stimulation / adverse effects*
  • Deep Brain Stimulation / methods*
  • Essential Tremor / diagnosis
  • Essential Tremor / physiopathology
  • Essential Tremor / therapy*
  • Female
  • Gait Disorders, Neurologic / etiology*
  • Gait Disorders, Neurologic / physiopathology
  • Gait Disorders, Neurologic / therapy
  • Humans
  • Male
  • Middle Aged
  • Postoperative Complications / diagnosis
  • Postoperative Complications / epidemiology
  • Postoperative Complications / physiopathology
  • Prospective Studies
  • Retrospective Studies
  • Ventral Thalamic Nuclei / pathology
  • Ventral Thalamic Nuclei / physiology
  • Ventral Thalamic Nuclei / surgery*