Directional deep brain stimulation of the centromedian thalamic nucleus reduces DBS-induced ataxia and dysarthria in Lennox-Gastaut Syndrome: A single case study

Background

We present a case of a 46-year-old man with Lennox-Gastaut syndrome and drug-resistant epilepsy. An adjunctive neurostimulation therapy strategy was implemented involving bilateral deep brain stimulation (DBS) of the centromedian thalamic nucleus (CMT).

Methods

Robotically assisted implantation of bilateral DBS directional lead system with 8 contacts in the CMT was performed. The clinical course was assessed in repeated in-patient follow-ups.

Results

Initial DBS stimulation resulted in progressive ataxia and dysarthria significantly beyond the level seen before surgery. Deactivation of DBS coincided with improvement of dysarthria. A DBS stimulation paradigm with reduction of lateral and superior stimulation resulted in improvement and eventually complete resolution of the stimulation side effect.

Discussion

This case suggests that stimulation-induced dysarthria in DBS can be improved by targeted reduction of lateral and/or superior thalamic stimulation. When dysarthria and ataxia occur during DBS, directed stimulation to medial thalamic structures and more inferior electrode contacts offers a promising strategy to reduce side effects while maintaining positive effects.