Thalamic stimulation in patients with multiple sclerosis.
OBJECTIVE
To assess tremor control and side effects in patients with multiple sclerosis (MS) treated with chronic thalamic stimulation for relief of upper extremity tremor.


METHODS
Five patients were studied before and after thalamic placement of a deep brain stimulation (DBS) system. Preoperative and postoperative evaluation included magnetic resonance imaging, Extended Disability Status Scale (EDSS), the Bain-Finchley visual analog scale for tremor, video recording and neuropsychological testing. Stereotactic targeting of the Vim nucleus was done using computed tomography; intraoperative testing was done under local anesthesia before permanent implantation.


RESULTS
Functionally useful tremor suppression was obtained in 3/5 patients. Neuropsychological deficits of higher cortical function, memory and visuospatial coordination were observed in all patients before surgery; in 1 patient with improved postoperative visuospatial coordination, worsened memory was found. New brainstem plaque formation was seen several weeks after surgery in 1 patient who had an acute worsening of MS which improved after high-dose intravenous steroids.


CONCLUSIONS
Chronic thalamic stimulation may help selected patients with MS-induced tremor. Given the complexity of their underlying illness, patients must be selected carefully, and long-term follow-up is vital to evaluate the true utility of DBS.
Schulder
M
M
Division of Neurosurgery and Department of Neuroscience, New Jersey Medical School, Newark, NJ, USA. schulder@umdnj.edu
Sernas
T
T
Mahalick
D
D
Adler
R
R
Cook
S
S
D000328:Adult; D004599:Electric Stimulation Therapy; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000150:complications* / Q000473:pathology; D009483:Neuropsychological Tests; D018579:Patient Selection; D012720:Severity of Illness Index; D014202:Tremor / Q000209:etiology / Q000628:therapy*; D020651:Ventral Thalamic Nuclei / Q000503:physiopathology*; D014741:Video Recording