Thalamic deep brain stimulation for management of essential tremor.

Abstract

Deep brain stimulation (DBS) of the thalamus is used for the treatment of patients with medically refractory essential tremor (ET). The authors evaluated patient outcomes after DBS surgery. Clinical outcomes were evaluated in 19 patients who had undergone DBS surgery by using the Fahn-Tolosa-Marin clinical tremor rating scale. All adverse outcomes were also systematically recorded during follow-up outpatient visits. Eighteen DBS systems were implanted. The median follow-up period after surgery was 27 months (range 10-75 months). The preoperative mean Fahn-Tolosa-Marin action tremor score was 3.3 +/- 0.5, and the postoperative mean score with the DBS system activated was 0.8 +/- 0.4. The mean preoperative writing score was 2.8 +/- 0.9, and the postoperative mean writing score with the DBS system activated was 1 +/- 0.6. (Wilcoxon rank-sum test, p < 0.005). Fourteen patients were treated with bipolar stimulation, and four eventually required monopolar stimulation. Complications included lead breakage (one patient); temporary erythema of the incision through which the pulse generator had been implanted, which required oral antibiotics (one patient); electrode migration, which required surgery (one patient); and mild hand tingling during stimulation (three patients). Twelve of 18 patients with implanted systems experienced no morbid condition. Thalamic DBS is safe and effective for medically refractory ET. Stimulator adjustments can frequently occur in some patients, and tremor may worsen despite a readjustment in the system.