Magnetic resonance-guided focused ultrasound thalamotomy as a viable option for essential tremor after deep brain stimulation explantation: illustrative case.

Background: Essential tremor (ET) has limited pharmacological treatments, and deep brain stimulation (DBS) has emerged as an effective surgical intervention. DBS, although effective and safe, is inherently invasive. Patients at high risk for surgery or who experience complications with DBS are left with limited treatments for medically refractory ET. Magnetic resonance-guided focused ultrasound (MRgFUS) is a less invasive and effective option for these patients.

Observations: A 67-year-old right-handed male with a 37-year history of refractory ET underwent DBS of the bilateral ventral intermediate nuclei. His postoperative course was complicated by infection requiring device explantation and tremor recurrence. The patient subsequently elected to undergo left MRgFUS thalamotomy. Postoperative imaging illustrated overlap of the left thalamic MRgFUS lesion with the decussating and nondecussating dentato-rubro-thalamic tracts, while avoiding the medial lemniscus and corticospinal tract. The postoperative lesion was slightly posterior and superior to the original DBS lead trajectory. The patient reported 90% tremor reduction 3 months posttreatment, and his Clinical Rating Scale for Tremor score dropped from 47 to 11 with significant quality of life improvement.

Lessons: While MRgFUS is not a replacement for DBS, it is an effective and less invasive option for patients with medically refractory ET at high risk for surgery or who fail treatment with DBS. https://thejns.org/doi/10.3171/CASE25240.