Therapeutic Outcomes of Directional Deep Brain Stimulation in Essential Tremor Patients
Alina Shub1, Donald Smith2, Theresa Zesiewicz1, Teresita Malapira2, Yarema Bezchlibnyk2
1Neurology, 2Neurosurgery, University of South Florida
Objective:
Analyzing directional deep brain stimulation (DBS) outcomes in Essential Tremor (ET) patients using the Abbott Infinity and Boston Scientific Vercise Systems.
Background:
Stimulation of the Ventralis Intermedius nucleus of the thalamus (VIM) effectively suppresses tremors in patients with ET. Data on the long-lasting benefits of directional current delivery remains limited.
Design/Methods:
Tremor was evaluated in 9 ET patients implanted with directional DBS leads using the Fahn-Tolosa-Marin Tremor Scale (FTM). One patient was subsequently diagnosed with parkinsonism. In our sample 7 patients were implanted bilaterally and 2 unilaterally, 7 implanted with Abbott Infinity and 2 with the Boston Scientific Vercise system. FTM assessments were obtained preoperatively and 7 to 16 months following device activation.
Results:
On average patients exhibited tremors for 23.3 ±17.9 years. Mean age at surgery was 67.2 ±11.0 years. Preoperatively FTM scores ranged from 36 to 88 points with a mean of 51.3 ±15.9, while 11.6 ±2.9 months post device activation FTM scores ON stimulation ranged 7 to 31 points and averaged 15.9±8.2. FTM scores ON stimulation at postoperative follow-up decreased by 66% when compared with FTM scores at baseline. Medication reduction or discontinuation was observed in 71% of patients who were prescribed tremor suppressing medications at baseline. Segmented DBS contacts were used in 15 of the 16 directional leads.