Thalamic Deep Brain Stimulation For Holmes Tremor (P6.056)

Objective: To describe the safety and efficacy of deep brain stimulation (DBS) of thalamic ventral intermediate nucleus (ViM) in nine patients with Holmes tremor (HT). Background: HT is a rare, disabling tremor characterized by rest, postural, and kinetic components. This tremor most often occurs in patients with multiple sclerosis, brainstem tumors, strokes, or vascular lesions. The pathophysiology involves the cerebellar outflow tracts and dopaminergic nigrostriatal fibers. Medications have limited success and DBS has emerged as an effective treatment option. We present our results on the largest case series of ViM DBS in patients with Holmes tremor. Design/Methods: Nine consecutive patients with HT tremor due to varying etiologies underwent ViM DBS. Baseline clinical analysis included mean age of onset, mean delay from acute illness to appearance of HT, tremor severity, etiologies of tremor, MRI findings, and response to oral medications. DBS lead placement was done with stereotactic MRI coordinates, microelectrode recording and intraoperative CT scan. The clinical response to DBS was measured using the Fahn Tolosa Marin Tremor Rating Scale. Effective programming parameters and settings were recorded. Side effects after surgery and during follow up were analyzed. Results: The etiologies of HT consisted of multiple sclerosis (4), cavernoma (2), osmotic demyelination (1), Lithium toxicity (1), and TBI (1). The mean age of onset of tremor was 46 years. All nine patients underwent ViM DBS with no serious adverse events. Five patients had bilateral DBS placement; four had unilateral (left). Mean follow up was three years. Responses to DBS varied from partial to complete tremor control (mean 59% reduction). Rest and postural tremor responded better than the kinetic component. Sequential and variable programming strategies were used to obtain maximum benefit. Conclusions: ViM DBS is a safe and effective treatment option for Holmes tremor. Disclosure: Dr. Krause has nothing to disclose. Dr. Prakash has nothing to disclose. Dr. Bucholz has nothing to disclose. Dr. Chand has nothing to disclose.