To assess the real-world efficacy and safety of staged-bilateral magnetic-resonance guided focused ultrasound (MRgFUS) thalamotomy in patients with refractory essential tremor (ET).

ET is a progressive neurological disorder characterized, mainly, by a bilateral action tremor that impairs patient’s quality of life (QoL). MRgFUS thalamotomy has emerged as a minimally invasive alternative for tremor control.

Observational cohort study. ET patients who underwent a staged-bilateral MRgFUS thalamotomy were included. The primary efficacy endpoint was the change in total Clinical Rating Scale for Tremor (CRST) score. Secondary endpoints included CRST subscales, patient- and clinician-reported outcomes, QoL (QoL in essential tremor questionnaire (QUEST), Euro QoL-5D-5L), and safety (adverse events, Scale for the Assessment and Rating of Ataxia (SARA) score and Timed Up and Go test). Endpoints were assessed at baseline and at 7 days, 3 and 6 months after the bilateral intervention.

40 patients were included (15 with a follow-up of 6 months), mean age 70.9(7.2)years, 72.5% were females. Compared to baseline, the CRST total score reduced significantly by an average of 48 points (82%) at six months post staged-bilateral thalamotomy (95% CI: -51.3 to -45.4; p<0.001). Axial CRST score improved by 91.67%. QUEST score improved by 35 points (84.96% of improvement;p<0.001). Six-months after the bilateral treatment, 58.5% of patients reported having a “very mild” or “mild” tremor, according to the patient global impression of severity, and 61.% of patients reported to have “very much improved”. Adverse events after the second thalamotomy were slightly higher than after the first one, with sensory disturbances being most common (33.3%), mild in all cases.

Staged-bilateral MRgFUS thalamotomy provides significant improvement in tremor severity and QoL among patients with ET. The intervention was generally well tolerated, with manageable safety concerns. Future research should explore long-term outcomes and direct comparisons with alternative surgical options.