gms | German Medical Science

Objective: To evaluate the long-term effect of thalamic deep brain stimulation (DBS) in a series of patients with severe tremor due to multiple sclerosis. DBS of the thalamic VIM has been shown to improve tremor in patients suffering from various tremor disorders. The issue of DBS in patients with tremor due to multiple sclerosis has been a matter of debate. Kinetic and postural tremors in multiple sclerosis may result in considerable functional impairment. Since tremor is only one of many symptoms in multiple sclerosis patients, the impact of thalamic DBS on overall disability remains unclear.

Methods: We evaluated the results of thalamic DBS on long-term outcome in a series of 11 patients. Mean age was 57 years (range, 31–75, 6 F / 5 M). All patients had a chronic progressive course of multiple sclerosis. Tremor was disabling in all instances. CT-stereotactic implantation of 3387 electrodes in the Vim was performed without surgical complications in all patients. In 9 patients the electrode was on the right side, in 2 patients on the left.

Results: All patients were available for long-term follow-up. Initial symptomatic improvement was present in all instances. This, however, did not correlate with functional improvement. Both symptomatic and functional long-term improvement was found only in single instances. Energy delivery was higher on the average than in other tremor disorders. In particular, patients with cognitive impairment did not benefit from thalamic DBS.

Conclusions: Thalamic DBS is a safe and modifiable treatment option for patient with severe disabling tremor due to multiple sclerosis. Nevertheless, patient selection remains a challenging task in this type of tremor.