Role of radiosurgical thalamotomy in the management for essential tremor: evidence from an international multi-institutional study.

INTRODUCTION

Essential tremor is a common movement disorder that can cause substantial functional disability when symptoms become medically refractory. Stereotactic radiosurgery (SRS) is a minimal access treatment strategy for tremor control, but multicenter outcome data remain limited.

METHODS

We performed a retrospective multi-institutional cohort study of 232 stereotactic radiosurgical thalamotomy procedures for medically refractory essential tremor. The median age at treatment was 76.0 years, median tremor duration was 17.0 years, median margin dose was 70.0 Gy, and median maximum dose was 140.0 Gy. The primary endpoint was clinically meaningful tremor improvement. Secondary endpoints included tremor arrest, recurrence, adverse radiation effects (AREs), and change in Fahn-Tolosa-Marín (FTM) scores. Logistic regression was used to evaluate outcome predictors.

RESULTS

Significant tremor improvement was observed in 92.1% of patients, with a median time to improvement of 4.0 months. Complete tremor relief occurred in 26.1%. Symptomatic AREs occurred in 4.3%. Tremor recurrence was noted in 12.4% at median follow-up of 2 years. Among procedures, mean unilateral hand FTM score improved from 12.53 to 5.07, corresponding to a mean improvement of 7.46 points (p < 0.001). Significant improvement was also observed across tremor, writing, drawing, and drinking sub scores (all p < 0.001). On multivariable analysis, a maximum lesion dose ≥ 140 Gy was independently associated with greater odds of clinical benefit (OR 3.44, p = 0.019).

CONCLUSION

In this multi-institutional cohort, SRS was associated with high rates of clinically meaningful tremor improvement, significant functional improvement, and durable tremor control in medically refractory essential tremor.