Magnetic resonance imaging-guided focused ultrasound thalamotomy for an essential tremor patient with a subcutaneous implantable cardioverter defibrillator: A case report

We report a 52 years-old, right-handed man with medication-refractory essential tremor (ET). Because of ventricular fibrillation (Vf) due to coronary spasm, he had been treated with an MR-conditional subcutaneous implantable cardioverter defibrillator (S-ICD) and medications including amiodarone, nifedipine, and isosorbide nitrate. Amiodarone was discontinued as Vf was not observed for more than 2 years, and it induced thyrotoxicosis. Vf did not occur after the cessation of amiodarone. Moreover, he did not suffer from an angina attack after the administration of vasodilators. After receiving informed consent to stop S-ICD during the procedure, we performed MRI-guided focused ultrasound (MRgFUS) left ventral intermediate nucleus thalamotomy. The right-hand tremor disappeared immediately, and we observed neither Vf nor S-ICD-related complications during the procedure. MRgFUS thalamotomy may be feasible as one of the therapeutic options for ET patients even with S-ICD.