Shannon Clark, M.D., presents a patient case where MRI guided focused ultrasound is successfully utilized to drastically reduce their essential tremor. Watch Dr. Clark perform this incisionless, outpatient treatment with immediate results.
My name is Shannon Clark. I'm a functional neurosurgeon with the Centara Neurosurgical Specialists. Today, I would like to show you a video clip of the new procedure I'm offering using focused ultrasound to treat essential tremor. Focused ultrasound is a minimally invasive procedure to use ultrasound to ablate VIM nuclei thalamus, thereby decreasing the unilateral hand tremor by 70 to 80% for long term. This is a 72 year old male with medically intractable essential tremor, undergoing MRI guided focused ultrasound for treatment of his right hand tremor. He failed medication management with propranolol and Primmione. The procedure is incisionless and the result is immediate. Patients can go home on the same day after the procedure, which takes approximately 2 hours. The procedure is only FDA approved for unilateral treatment at this time, so we only treat the site that is affected more by the essential tremor. In the morning of the surgery, patient's head will be completely shaved to ensure there is no air bubble trapped in here, as the air bubbles prevent ultrasound propagation. After the head shave, an MRI compatible rigid flame that fixes patient's head in ultrasound helmet will be first placed on the patient's skull using 4 pins. We first numb the pin sight with long acting local anesthetics. The patient will feel some pressure. While the frame is applied but no sharp pain, once the frame is on, a silicon membrane will be placed over the scalp and the frame in a watertight fashion. The silicon membrane acts as a barrier to the chilled saline infused in between ultrasound helmet and the patient's scalp to prevent the saline from leaking down the patient's face or MRI table. Once the patient is prepped and ready for the procedure, he will be. to the MRI magnet. Here we first obtained the baseline tremor severity by having the patient perform simple task of touching his index fingers together. As you can see, he had severe right hand tremor preventing from him performing accurately touching the index fingers. Here is the baseline spiral and line drawing using his right hand showing severe tremor. During the actual procedure, we first acquire an MRI of patient's brain to identify the ablative target. For this patient, we target left VIM nuclei of thalamus to treat right hand tremor. The scan time and targeting planning takes about 30 minutes and the procedure can begin. We first deliver low dose of ultrasound energy to increase the temperature to 50 °C only. This allows testing without permanently creating a lesion. The purpose of the testing is to see if the target gives therapeutic benefit and, more importantly, to confirm the patient doesn't develop side effect. Next, we proceed with treatment ablation by increasing the energy delivered and treatment temperature to 60 °C. This ablation takes only about 30 seconds to complete. During the ablation, the patient may experience transient headache, which resolves as soon as ultrasound delivery ends. Here is the final treatment testing, and you can see that his right index finger has nearly completely stopped tremoring. and here is the spiral post treatment, and he was able to complete the task satisfactorily. Post treatment, the patient was brought out of the MRI control room and again the frame is removed and Uh testing is performed. He is able to do finger to nose testing without any difficulty. This patient had greater than 90% reduction in right hand tremor. And finger to finger is also very smooth and he was able to draw spiral easily. He was able to go home after this procedure and when he presented for follow-up appointment in 2 weeks in my clinic, his tremor was still well controlled, and he remains free of any adverse event.
BROADCASTMED