This study aims to evaluate the safety and effectiveness of simultaneous bilateral radiofrequency thalamotomy for patients with medication-refractory essential tremor (ET). Essential tremor is a common neurological condition that causes involuntary shaking, often affecting the hands and interfering with daily activities such as writing, eating, or using tools. While medications such as propranolol and primidone can help some patients, others experience limited or no benefit.
In this study, five adult participants diagnosed with essential tremor that does not respond to standard medications will undergo simultaneous bilateral stereotactic radiofrequency lesioning of the ventral intermediate nucleus (Vim) of the thalamus. This procedure involves precisely targeting both sides of the Vim to reduce tremor in both arms during a single surgical session.
Prior to surgery, participants will undergo brain MRI for surgical planning, as well as clinical evaluations including the Clinical Rating Scale for Tremor (CRST), Quality of Life in Essential Tremor Questionnaire (QUEST), the Scale for the Assessment and Rating of Ataxia (SARA), mood scales (BDI, BAI, AES), and cognitive function testing.
The surgery will be performed under local anesthesia using a stereotactic frame and intraoperative imaging. Tremor reduction will be assessed postoperatively and at 1, 3, and 6 months. The primary outcome is the improvement in CRST scores at 6 months. Secondary outcomes include quality of life (QUEST), ataxia symptoms (SARA), mood and cognitive changes, and adverse events.
This research is being conducted at Tokyo Women's Medical University. The study is IRB-approved and participants will be monitored closely throughout the 6-month follow-up period. Any complications or adverse events, such as temporary speech or swallowing difficulties, will be recorded and managed appropriately. The goal of this study is to explore whether performing thalamotomy on both sides simultaneously is a safe and effective treatment option for patients with severe and medication-resistant essential tremor.
Adults aged 20 to 70 years.
Diagnosis of essential tremor by a neurologist or neurosurgeon specializing in movement disorders.
Refractory to standard pharmacological therapy (e.g., propranolol, primidone, benzodiazepines, or alprenolol).
Mini-Mental State Examination (MMSE) score ≥ 27.
History or evidence of bleeding tendency.
MRI contraindications (e.g., metallic implants, severe claustrophobia).
Presence of intracranial pathology on preoperative MRI that would interfere with surgery.
Pregnant or breastfeeding individuals.
Single group
Simultaneous Bilateral RF Thalamotomy
Procedure/SurgeryThis intervention involves simultaneous bilateral radiofrequency (RF) lesioning of the ventral intermediate nucleus (Vim) of the thalamus using a stereotactic frame under local anesthesia. The procedure begins with RF ablation on the side contralateral to the dominant hand. Intraoperative MRI is then performed to confirm the absence of hemorrhagic complications. If no bleeding or other adverse events are detected, the procedure proceeds to the contralateral Vim. If hemorrhage is identified, the surgery is terminated after unilateral treatment. This technique allows for immediate bilateral tremor reduction in patients with medication-refractory essential tremor, while prioritizing patient safety through intraoperative imaging-based decision-making.
Change in Clinical Rating Scale for Tremor (CRST) Score From Baseline to 6 Months Postoperatively
The Clinical Rating Scale for Tremor (CRST) is a standardized scale used to evaluate tremor severity and its impact on motor function and activities of daily living. The total CRST score includes postural and action tremor, writing, pouring tasks, and disability ratings. Higher scores indicate greater severity. The primary outcome is the change in total CRST score from preoperative baseline to 6 months after the bilateral radiofrequency thalamotomy.
Change in QUEST Score From Baseline to 6 Months Postoperatively
The Quality of Life in Essential Tremor Questionnaire (QUEST) is a disease-specific instrument used to assess the impact of essential tremor on patients' quality of life. It includes items related to physical, psychosocial, and communication aspects. Higher scores indicate greater impairment.
Change in SARA Score From Baseline to 6 Months Postoperatively
The Scale for the Assessment and Rating of Ataxia (SARA) is a clinical scale that measures cerebellar ataxia symptoms such as gait, stance, limb coordination, and speech. Scores range from 0 (no ataxia) to 40 (severe ataxia). Higher scores indicate more severe impairment.
Change in BDI Score From Baseline to 6 Months Postoperatively
The Beck Depression Inventory (BDI) is a widely used 21-item self-report questionnaire for assessing the severity of depressive symptoms. Scores range from 0 to 63, with higher scores indicating more severe depression.
Change in BAI Score From Baseline to 6 Months Postoperatively
The Beck Anxiety Inventory (BAI) is a 21-item self-report instrument used to assess the severity of anxiety symptoms in adults. Total scores range from 0 to 63, with higher scores reflecting greater anxiety.
Map coordinates are unavailable for these locations. Locations are shown below instead.
JapanClick on the lead sponsor to view all of their trials.
