Longitudinal follow-up of dual-lead thalamic deep brain stimulation for patients with treatment refractory multiple sclerosis tremor

Objective: To report longitudinal outcomes of tremor improvement in patients with medically refractory MS tremor. Background: Multiple Sclerosis (MS) tremor is typically pharmacoresistant and disabling. Studies of treatment outcomes with stereotactic lesioning or single-lead deep brain stimulation (DBS) have been variable. Dual-lead thalamic DBS targeting the ventralis intermedius (VIM) and ventralis oralis (VO) has been shown to be a safe and effective therapy. Currently there is limited data on long-term outcomes of dual-lead thalamic DBS for tremor management. We report long-term outcomes in a cohort of patients with medically refractory MS tremor treated with dual-lead thalamic DBS. Design/Methods: Retrospective review of 19 patients with medically refractory tremor who underwent dual-lead thalamic DBS from 2007–2015. In this study 15 patients were included who were evaluated using the Tolosa-Fahn-Marin Tremor Rating Scale (TRS) before surgery and on-stimulation at 1, 3, and 5 years postoperatively. Results: Median total TRS scores improved from baseline during a five-year follow-up (p=0.026). Median TRS motor scores were reduced from baseline during this period (p=0.044). No statistically significant differences were found in TRS activities of daily living (ADL) scores postoperatively compared to pre-surgical baseline (p=0.212). Conclusions: Dual-lead thalamic DBS is potentially an effective treatment for the long-term improvement of severe, medication refractory tremor in MS. Although there is an improvement in motor scores, the disability questionnaire components remained unchanged from baseline, this may be related to disability due to underlying ataxia. Disclosure: Dr. Patel has nothing to disclose. Dr. Barmore has nothing to disclose. Dr. El Kouzi has nothing to disclose. Dr. Zeilman has nothing to disclose. Dr. Almeida has nothing to disclose. Dr. Foote has nothing to disclose. Dr. Okun has received personal compensation for consulting, serving on a scientific advisory board, speaking, or other activities with Parkinson’s Foundation, Medscape, Mededicus, AAN, PeerView, Prime, Henry Stewart, and MDS. Dr. Okun has received personal compensation in an editorial capacity for New England Journal of Medicine Journal Watch and JAMA Neurology.