Multiple target deep brain stimulation for multiple sclerosis related and poststroke Holmes' tremor

Area of Science:

• Neurology
• Neurosurgery
• Biomedical Engineering

Background:

• Thalamic deep brain stimulation (DBS) often yields disappointing results for atypical tremor syndromes, such as those associated with multiple sclerosis (MS) and stroke.
• Recent case reports suggest potential benefits from stimulating multiple thalamic targets simultaneously.

Observation:

• This study investigated multi-target DBS in one patient with MS-related tremor and another with post-stroke Holmes' tremor.
• In the MS tremor patient, bilateral ventralis intermedius (V.im.) and ventralis oralis anterior (V.o.a.) electrodes were implanted. Stimulation of either V.im. or V.o.a. alone improved tremor, but simultaneous stimulation showed no additive benefit.
• In the Holmes' tremor patient, electrodes were implanted in the unilateral V.im., V.o.a., and globus pallidus internus (Gpi). Gpi stimulation alone provided moderate tremor reduction, while V.im. and V.o.a. stimulation offered no additional benefit.

Findings:

• Simultaneous V.im. and V.o.a. stimulation was not superior to single-target stimulation in the MS tremor patient.
• Globus pallidus internus (Gpi) stimulation proved to be a viable alternative to thalamic stimulation for the patient with post-stroke Holmes' tremor.

Implications:

• Multi-target thalamic DBS may not offer superior tremor control compared to single-target stimulation in certain atypical tremor conditions.
• Globus pallidus internus (Gpi) stimulation represents a potential alternative therapeutic target for managing refractory Holmes' tremor.
• Further research is warranted to explore optimal DBS targeting strategies for diverse tremor etiologies.