Efficacy and Safety of the Felix NeuroAI Wristband for Essential Tremor: Results of a 1-Year Open-Label Extension Trial.

BACKGROUND: Essential tremor (ET) impacts daily activities and quality of life. A pivotal study of a transcutaneous peripheral nerve stimulation (TPNS) device, the Felix NeuroAI Wristband, led to Food and Drug Administration (FDA) clearance in 2025. OBJECTIVE: The aim of the study was to report 1-year follow-up results. METHODS: Patients who completed the 90-day randomized phase could continue until 1 year after the baseline visit; those in the sham group were crossed over to active TPNS treatment (delayed-start TPNS). Outcome measures were assessed at 180 days and 1 year: modified Activities of Daily Living (mADL) subscale of TETRAS, Clinical and Patient Global Impression of Improvement (CGI-I and PGI-I), Quality of Life in Essential Tremor Questionnaire, and adverse device effects (ADEs). RESULTS: Of 93 patients who entered the extension phase (58 TPNS and 35 delayed start), 57 (38 and 19, respectively) completed 1 year of follow-up. In the TPNS group, mADL improvement increased from 6.9 points at day 90 to 9.7 points at 1 year. Ninety days of active treatment improved mADL scores by 5.5 points in the delayed-start TPNS group (day 180). From baseline, TETRAS ADL scores in the TPNS group improved by 6.1 ± 6.0 points at 90 days and 9.3 ± 6.0 points at 1 year. CGI-I, PGI-I, and quality of life improved in both groups from 90 days to 1 year. Twenty-three new ADEs occurred (mild skin irritation, n = 22; muscle spasms, n = 1). CONCLUSIONS: TPNS use was associated with sustained functional improvement for up to 1 year with acceptable safety. Patients who initiated active therapy earlier demonstrated greater cumulative benefit.