Dual target deep brain stimulation for complex essential and dystonic tremor - A 5-year follow up

J Neurol Sci. 2024 Feb 15:457:122887. doi: 10.1016/j.jns.2024.122887. Epub 2024 Jan 26.

Abstract

Background: Essential tremor (ET) is characterized by action tremor of the upper limbs, head tremor and voice tremor. Dystonic tremor (DT) is produced by muscle contractions in a body affected by dystonia. Deep brain stimulation (DBS) of ventral intermediate nucleus of the thalamus (VIM) is the most well-known advanced treatment for medication-refractory tremor. However, decline in efficacy overtime has led to explore other targets. This study aimed to measure the efficacy of bilateral dual targeting ViM/caudal Zona Incerta (cZI) stimulation on tremor control. A secondary aim was to evaluate if there was a difference in the efficacy between ET and DT.

Methods: 36 patients were retrospectively recruited at the Walton NHS Foundation Trust, Liverpool, UK. Patients were assessed pre-operatively, and then at 1-year, 3-years, and 5-years post-operatively with the following scales: Fahn-Tolosa-Marin tremor rating (FTMTR) scale, EuroQol-5D, and Hospital Anxiety and Depression Scale.

Results: Bilateral ViM-cZI DBS significantly improved overall tremor score by 45.1% from baseline to 3-years post-operatively (p < 0.001). It continued to show improvement in overall FTMTR score by 30.7% at 5-years but this failed to meet significance. However, there was no significant improvement of mood or quality of life (QoL) scores. ET group on average showed a significant better clinical outcome compared to the DT group (p > 0.001).

Conclusions: Our study found that bilateral ViM-cZI DBS treatment had a favourable effect on motor symptoms sustained over the 5-years in tremor patients, especially in ET group. There was limited effect on mood and QoL with similar trends in outcomes for both tremor types.

Keywords: Deep brain stimulation; Dentato-rubro-thalamic tract; Dystonic tremor; Essential tremor; Posterior subthalamic area (PSA); Ventral intermediate nucleus of the thalamus (ViM).

MeSH terms

  • Deep Brain Stimulation* / adverse effects
  • Dystonia* / etiology
  • Essential Tremor* / therapy
  • Follow-Up Studies
  • Heredodegenerative Disorders, Nervous System*
  • Humans
  • Quality of Life
  • Retrospective Studies
  • Treatment Outcome
  • Tremor / etiology
  • Tremor / therapy

Supplementary concepts

  • Fatty Acid Hydroxylase-Associated Neurodegeneration