Introduction: We have recently described dual VIM and VO thalamic deep brain stimulation (DBS) for surgical treatment of severe multiple sclerosis tremor. One potential adverse outcome of dual thalamic DBS is cognitive or other neuropsychologic decline related to increased lesional and/or stimulation volume.
Methods: 12 patients with refractory MS tremor all underwent ipsilateral VIM and VOA-VOP DBS and were randomized to initial Vim On or VOA-VOP On stimulation for 3 months. After this all patients had both leads activated and optimized, then returned for a six month evaluation of all conditions (On VIM, On VOA-VOP, both On, and both Off). A neuropsychiatric battery was performed at all timepoints described in addition to the primary outcome measures for Tremor Rating Scale.
Results: Mild worsening of performance on neuropsychiatric battery testing was observed in only a subset of patients after dual lead thalamic DBS implantation. Most postoperative changes were not considered to be clinically significant. Those patients with neuropsychological impairment at baseline were more likely to experience postoperative decline.
Conclusions: Overall, dual lead thalamic DBS has minimal effect on neuropsychological performance. However, careful patient selection with thorough preoperative evaluation is critical to avoid postoperative neuropsychological decline.
Patient Care: By further characterizing the efficacy and safety of dual lead DBS for severe multiple sclerosis tremor
Learning Objectives: Describe preoperative evaluation measures that can potentially be used to identify high-risk patients for dual lead thalamic DBS