Tremor Rebound Due to a Deep Brain Stimulation Electrode Fracture with Normal Impedance Treated by Rescue Thalamotomy in a Patient with Essential Tremor: A Case Report

Abstract

Background: Deep brain stimulation (DBS) has been shown to be an effective treatment for essential tremor and other movement disorders. However, hardware-related complications have limited its efficacy. Lead fracture in DBS typically occurs in the cervical area in high-risk patients. Surgical revision is needed to relieve worsened tremor symptoms in these cases. Case Report: An 89-year-old woman with a history of bilateral DBS to the ventralis intermedius nucleus for essential tremor presented with worsened tremor in the right upper limb. Examination revealed normal impedance. Increased stimulation did not improve her tremor symptoms. Radiographic examination revealed lead fracture. Given the patient’s high surgical risk we performed thalamotomy followed by extraction of the electrode lead from the left ventralis intermedius nucleus. Conclusion: Lead fracture is a hardware-related complication of DBS and should be suspected if a patient complains of sudden-onset rebound tremor, even when electrical impedance values are within the normal range. Imaging studies should be performed, and thalamotomy may be an option for patients in whom the risks of general anaesthesia preclude surgery.

Keywords

• Essential tremor
• Deep brain stimulation
• Lead fracture