Object: The goal of this study was to evaluate short- and long-term benefits in quality of life (QOL) after unilateral deep brain stimulation (DBS) for essential tremor (ET).
Methods: Patients who received unilateral DBS of the ventral intermediate nucleus of the thalamus between 1997 and 2010 and who had at least 1 follow-up evaluation at least 1 year after surgery were included. Their QOL was assessed with the Parkinson Disease Questionnaire-39 (PDQ-39), and ET was measured with the Fahn-Tolosa-Marin tremor rating scale (TRS) prior to surgery and then postoperatively with the stimulation in the on mode.
Results: Ninety-one patients (78 at 1 year; 42 at 2-7 years [mean 4 years]; and 22 at >7-12 years [mean 9 years]) were included in the analysis. The TRS total, targeted tremor, and activities of daily living (ADL) scores were significantly improved compared with presurgical scores up to 12 years. The PDQ-39 ADL, emotional well-being, stigma, and total scores were significantly improved up to 7 years after surgery compared with presurgical scores. At the longest follow-up, only the PDQ-39 stigma score was significantly improved, and the PDQ-39 mobility score was significantly worsened.
Conclusions: Unilateral thalamic stimulation significantly reduces ET and improves ADL scores for up to 12 years after surgery, as measured by the TRS. The PDQ-39 total score and the domains of ADL, emotional well-being, and stigma were significantly improved up to 7 years. Although scores were improved compared with presurgery, other than stigma, these benefits did not remain significant at the longest (up to 12 years) follow-up, probably related in part to changes due to aging and comorbidities.