Late-Onset Ataxia after Thalamic Deep Brain Stimulation for Tremor Linked to Therapy Escape

Area of Science:

• Neurology
• Neurosurgery
• Biomedical Engineering

Background:

• Thalamic ventral intermediate nucleus (VIM) deep brain stimulation (DBS) effectively treats pharmacoresistant tremor.
• Tremor habituation occurs in a significant portion of patients, with reported rates varying widely.
• Late-onset ataxia is a potential adverse event following DBS, but its risk factors remain poorly understood.

Purpose of the Study:

• To identify predictors for the onset of ataxia in patients receiving VIM DBS for tremor.
• To investigate the potential connection between DBS-induced ataxia and tremor habituation.

Main Methods:

• Retrospective, observational, monocentric study conducted at Nice University Hospital.
• Inclusion of patients with VIM DBS for essential tremor, Parkinson's disease, and other tremor etiologies.
• Collection of data on DBS parameters, tremor type, ataxia onset, and tremor habituation.

Main Results:

• 30 out of 61 patients developed ataxia, with a mean onset of 36 months post-surgery.
• The ataxic group showed significantly more DBS setting modifications and higher rates of tremor habituation.
• Discontinuation of nighttime stimulation was correlated with a reduced incidence of ataxia.

Conclusions:

• A strong statistical relationship exists between ataxia and habituation, suggesting they may represent the same phenomenon.
• Early habituation within the first year post-DBS may predict the development of late-onset ataxia.
• Intermittent DBS stimulation appears to be a protective factor against late-onset ataxia.