Using Focused Ultrasound for Medically Refractory Lobe Focal Onset Epilepsy

Vibhor Krishna, MBBS, a neurosurgeon at The Ohio State University Wexner Medical Center

Vibhor Krishna, MBBS

Recently, the first patient was treated in a first-in-world clinical trial of focused ultrasound therapy for adults with medically refractory lobe focal onset epilepsy at The Ohio State University College of Medicine.¹

The pilot study (NCT03417297) will seek to enroll up to 10 patients to test the treatment, which utilizes 1024 MR-guided focused ultrasound beams to converge upon a focal point in the brain to ablate the specific tissue involved in the patient’s epilepsy. The first patient treated was a 58-year-old man that underwent the 3-hour procedure in an intraoperative MRI-surgical suite, in early January.

Maurice Ferré, MD, the chairman and CEO of INSIGHTEC, the technology’s developer, told NeurologyLive that “focused ultrasound is transforming healthcare,” adding that the company is “committed to supporting research sites working on advancing new applications, such as epilepsy, and believe one day, incisionless surgeries will be an accessible option for patients around the world.”

To find out more about this first-of-its-kind trial, NeurologyLive spoke with Vibhor Krishna, MBBS, a neurosurgeon at The Ohio State University Wexner Medical Center who is leading the trial, about the goals of the study and what the clinician community needs to know.

NeurologyLive: What’s the goal of this clinical trial and what’s been seen in previous assessments?

Vibhor Krishna, MBBS: In a first-in-world clinical trial, we are studying the safety-focused ultrasound ablation in a specific type of epilepsy where seizures are not controlled by medication. The study will enroll up to 10 adults, ages 18 to 65, who have medically refractory focal onset epilepsy.

The primary objective is to assess the safety of anterior nucleus ablation. Safety will be assessed by the absence of adverse effects, such as new-onset neurological deficits, performance deterioration on neuropsychological testing.

This is a first-in-man trial of anterior nucleus ablation. Some small case series dating back to 1960s and ‘70s had reported a decrease in seizure frequency after thalamotomy with radiofrequency ablation. In subsequent years, electrical stimulation of thalamus was tested in this patient population. Currently, deep brain stimulation of anterior nucleus is FDA approved for the treatment of focal onset epilepsy.

What does the clinical community need to know about this?

MR-guided focused ultrasound is an emerging technology which uses 1024 ultrasound beams to create ablation at a focal spot in the brain. It is currently an FDA-approved for the treatment of essential tremor and tremor-dominant Parkinson disease. The commercially available INSIGHTEC Exablate 4000 mid-frequency (650 kHz) system will be used in the study.

What’s the ideal patient look like for this technique?

An ideal patient for this study is someone who has been diagnosed with focal onset epilepsy with secondary generalizations who have been refractory to at least 2 medications. We are seeking patients with high seizure frequency—3-4 times a month or more—and those willing to maintain a seizure diary for this research study.

The study participants will be screened from the patients being cared for by the epilepsy program at The Ohio State University Wexner Medical Center or referred from elsewhere for enrollment in the study. We will review their medical history pertaining to the patient’s epilepsy (duration, severity previous treatment, etc.) and their complete medication history, along with conducting a series of medical exams including CT and MRI imaging and neuropsychology testing.

How does this technology change the landscape of epilepsy surgery?

More than 20 million people worldwide are suffering from seizures that cannot be controlled with medication. Surgical resection of the epilepsy focus can be very effective for controlling seizures. However, not all patients are eligible to undergo surgical resection due to several reasons including the location and resectability of the epileptic focus. This leaves a significant number of epilepsy patients without further treatment options. We aim to test the safety of this procedure in this Phase-1 study and, if proven safe, we plan to undertake further studies (phase 2/3) to determine its effectiveness. With these research efforts, we hope to establish whether anterior nucleus ablation with focused ultrasound can be another option for patients with medication-refractory focal onset epilepsy.

Transcript edited for clarity.