Prospective, Multicenter, International Outcomes Study of Deep Brain Stimulation for Essential Tremor

INTRODUCTION: Essential Tremor (ET) treatment is focused on medical management of motor symptoms and includes pharmacotherapy and ventral intermediate nucleus (VIM) thalamotomy, which is being largely replaced by thalamic Deep Brain Stimulation (DBS) as the surgical treatment of choice. DBS of the VIM thalamus is recommended as a therapeutic option for appropriate subjects with ET (Elble RJ., et al. Expert Rev Neurother. 2018). METHODS: This is a prospective, on-label, multi-center, international DBS outcomes study conducted at up to 50 implanting centers. All participants are implanted with a multiple-source, constant-current directional DBS system (Vercise, Boston Scientific). Subjects are followed for up to 3-years post implantation where their overall improvement in quality of life and ET symptoms are evaluated. Clinical endpoints evaluated at baseline and follow-up timepoints include: The Essential Tremor Rating Assessment Scale (TETRAS), Quality of Life in Essential Tremor Questionnaire (QUEST), Fahn-Tolosa-Marin Rating Scale (TRS), and Global Impression of Change. Adverse events also collected. RESULTS: To date, 18-implanted subjects with a mean disease duration of 15.1 ± 14.6-years and a baseline QUEST Summary Index score of 35.0 ± 12.4. At 6-months post-DBS, a clinically significant improvement in quality of life (∆ = 19.5-point change in QUEST SI score) was reported. In addition, a mean 9-hours of tremor reduction was noted (14-hours at Baseline, 6.9-hours at 6-months) in a typical day at 6-months. All subjects (100%) reported mild disability, and no subject reported moderate or marked disability (89% at baseline) as reported by TRS at 6 months. CONCLUSIONS: This work represents the first comprehensive, large scale collection of real-world outcomes and evaluation of safety and effectiveness of a multiple-source, constant-current DBS system capable of providing directionality for use in treatment of Essential Tremor.