Deep brain stimulation in uncommon tremor disorders: indications, targets, and programming

Area of Science:

• Neuroscience
• Neurology
• Neurosurgery

Background:

• Uncommon tremor disorders often lack sufficient research on deep brain stimulation (DBS) efficacy and optimal surgical targets.
• Clinical evidence for DBS in these conditions is limited, hindering treatment standardization.

Purpose of the Study:

• To systematically review the existing literature on deep brain stimulation (DBS) for various uncommon tremor disorders.
• To assess the clinical efficacy and identify potential anatomical targets for DBS in these conditions.

Main Methods:

• A systematic review of PubMed.gov and ClinicalTrials.gov was conducted.
• Keywords included "tremor", specific tremor types (e.g., "Holmes tremor", "orthostatic tremor"), and associated conditions (e.g., "multiple sclerosis", "neuropathy", "fragile X-associated tremor/ataxia syndrome").

Main Results:

• 263 cases of uncommon tremor disorders treated with DBS were analyzed, including Holmes tremor (44), orthostatic tremor (18), multiple sclerosis tremor (177), neuropathy-associated tremor (14), and fragile X-associated tremor/ataxia syndrome (10).
• Deep brain stimulation (DBS) generally yielded favorable, though often partial, clinical improvements across various tremor types, with specific target responses noted (e.g., Vim-DBS, Vim-/VO-DBS).
• Sustained improvement was observed in orthostatic tremor with bilateral Vim-DBS, while results for fragile X-associated tremor/ataxia syndrome were mixed regarding ataxia.

Conclusions:

• Deep brain stimulation (DBS) targeting specific brain regions may be an effective treatment for uncommon tremor disorders.
• The current evidence is preliminary, based on limited case series, necessitating further investigation.
• An international registry is recommended to establish clear selection criteria, evaluate long-term outcomes, and refine optimal surgical targets for DBS in these conditions.