Chronic thalamic stimulation for the tremor of multiple sclerosis

The authors studied chronic high-frequency stimulation of the ventral inter mediate nucleus of the thalamus (Vim) for controlling upper extremity tremo r in patients with MS using MRI, CT, and microelectrode recordings and stim ulation to locate optimal target sites. Fifteen patients underwent surgery. All patients had reduced tremor but developed tolerance requiring repeated programming of the stimulator. Benefit at optimal stimulator settings was maintained. Two patients experienced complications: intracerebral hematoma and MS exacerbation. Chronic high-frequency stimulation of Vim provides tre mor reduction if patients have access to frequent stimulator adjustments. T his surgery is relatively safe.