Left Radiofrequency Thalamotomy for Drug-Refractory Essential Tremor

Abstract

Essential tremor is an idiopathic movement disorder characterized by bilateral action tremor of the upper limbs with or without other neurologic symptoms.¹ Pharmacologic management is the first-line treatment for this condition. Surgical treatment includes deep brain stimulation and thalamotomy procedures.² Furthermore, thalamotomy can be achieved by magnetic resonance imaging-guided focused ultrasound, stereotactic radiosurgery, or radiofrequency.³ Advantages of modulation therapies include bilateral implementation, adjustability, and reversibility of the effect.² Disadvantages include delayed response, increased infection risk, and cost. Within ablation therapies, focused ultrasound is costly and not available widely, while stereotactic radiosurgery has a delayed symptomatic relief. Radiofrequency represents a cost-effective, widely available option with immediate results.³ We present the case of a 91-year-old right-handed man with essential tremor refractory to medical management (Video 1). He was offered all available treatment modalities and opted for a radiofrequency thalamotomy. Preoperative planning included stereotactic head frame placement and computed tomography scan. A left thalamic target with coordinates 11.5 mm lateral to the wall of the third ventricle, 8 mm anterior to the posterior commissure, and at the rostrocaudal level of the anterior commissure-posterior commissure plane was chosen. A 1.1-mm diameter, 10-mm tip RF electrode was advanced to the target. A lateral radiograph was taken to verify the position of the electrode. After trial stimulation, 2 RF lesions were performed. No intraoperative complications occurred. Immediate postoperative MRI showed an enhancing focus in the left thalamic lobe corresponding to the left thalamotomy lesion. The patient had excellent relief of tremor during his last follow-up, 5 months postoperatively.

Keywords: Essential tremor; Radiofrequency; Stereotactic and stimulation; Thalamotomy.