Thalamic deep brain stimulation in the treatment of essential tremor

Abstract

Background and purpose

Quality of life can be severely impaired by essential tremor (ET) being the main cause of the patient's disability. The authors present a group of ET patients treated with deep brain stimulation of the ventral intermediate nucleus of the thalamus (Vim DBS). The aim of the study was to evaluate the efficacy and safety of Vim DBS in the treatment of ET.

Material and methods

Between 2006 and 2009, 8 female and 10 male ET patients were treated with Vim DBS. Mean age at implantation was 63 ± 15 years. ET lasted from 4 to 30 years (mean 12 years). Clinical condition of the group was evaluated before surgery and 3 months after implantation with spirography (spiral drawings), the modified Fahn (Tremor Rating Scale, TRS) scale, and the modified ADL (Activity of Daily Living) scale. The Vim was localized with CT and MRI. The procedures of implantation were performed under local and general anaesthesia. A bilateral procedure was performed in 11 cases and a unilateral procedure was performed in 7 cases.

Results

The therapeutic effect of DBS was maintained at the follow-up in the third month following surgery. Mean contralateral limb tremor reduction was 79%. Head tremor reduction was reported by 75% of patients in the bilateral Vim DBS subgroup and 50% of patients in the unilateral Vim DBS subgroup. Mean ADL score improved by 61%.

Conclusions

Vim DBS is a safe and effective method of ET treatment. Vim DBS improves activities of daily living of ET patients.