Since 2003, Thatcher Carr experiences an average of 85 seizures per month. The 46-year-old boat mechanic has a type of epilepsy that causes his muscles to freeze and stop speaking, as if trapped in his own body.
"I was so angry and embarrassed, honestly," said Carr. "It took so much away from me, even my military career. I was discharged because I was experiencing uncontrollable seizures and left feeling like damaged goods."
But that is in the past. Thanks to a new investigational procedure at UNC that uses sound waves to redirect electric signals in the brain, Carr is down to less than one seizure a month. Now, he can get back to what matters most: fixing boats and enjoying life with his cats, dogs, and wife, Debbie, uninterrupted.
Vibhor Krishna, MD, an associate professor of neurosurgery at the UNC School of Medicine, is a recognized expert in focused ultrasound and has played a significant role in ushering in focused ultrasound as a standard treatment for essential tremors and Parkinson's disease nationwide.
Vibhor Krishna, MD
Krishna's latest endeavor is an FDA-regulated study intervention aimed at advancing care for patients experiencing disruptive seizures.
"This is the first known FDA-regulated focused ultrasound ablation trial in the world to assess the safety, feasibility, and preliminary efficacy of focused ultrasound in adult patients with treatment-refractory focal onset epilepsy," said Krishna. "We are working tremendously hard to collect safety and efficacy data to be able to make it an FDA approved treatment one day."
What is Epilepsy?
Epilepsy syndromes are caused by abnormal electrical activity in the brain, leading to a variety of events that involve muscle movements not under your control and possibly loss of awareness.
Thatcher experienced his first seizure more than 20 years ago, when he was in naval history class at the Naval Academy. As he watched the clock, a sudden heaviness overcame him, and he sank into his seat, followed by a two-minute seizure.
The Naval Hospital in Washington, D.C. performed various neurological and heart tests to find the cause. There, he was quickly diagnosed with focal epilepsy and was put on an anti-epileptic drug, Dilantin, to slow down overactive brain signals and decrease the occurrence of seizures.
How is Epilepsy Treated?
Epilepsy can be managed in many ways, including medication, procedures that remove brain tissue, and the surgical installation of a pacemaker-like device for the brain.
"With the medication, his epilepsy is really quiet," said Debbie, who met her husband in 2013. "I've acquired this sixth sense to know when he is having an event. It's very subtle to where I have had to point it out to doctors and say 'it's happening right now.'"
Lynn Liu, MD, MS
However, treatment can be tricky. Many patients do not respond well to medication or their response wanes over time. And surgical procedures are invasive and can introduce more risk.
"For people with epilepsy that cannot be controlled by medications or surgery, they can feel frustrated and lose hope," said Lynn Liu, MD, who is a professor of neurology and chief of the epilepsy division at the UNC School of Medicine.
"For those with focal epilepsy, focused ultrasound can provide us with an opportunity with a targeted non-invasive approach. My priority, as the epileptologist on this study, is to ensure the safety of this technology so we can advance novel options for patients who urgently need them."
Surgical Interventions for Epilepsy
Eventually, Carr's medication waned in its effectiveness. In August 2021, he underwent a mapping procedure in Miami, F.L., to pinpoint the brain tissue that was causing the seizures.
Twenty large probes were embedded into Carr's brain to triangulate the source of the seizure, much like phone towers.
Imaging from Thatcher's mapping procedure. Credit: Thatcher Carr.
"The doctor pulled up the screen and showed us exactly where the area was," his wife explained. "There was so much excitement from the doctor because, for a lot of people who suffer with epilepsy, they never find where it is coming from."
After removing the irritable brain tissue, neurosurgeons found bruising. Whether it was from his military experience, falling out of a tree as a child, or getting hit square in the head with a baseball in his youth, they do not know what trauma may have initiated seizure activity.
And, even after the complex procedure, Carr's seizures were still inhibiting his daily life.
He was in desperate need of a more modern solution that could help him regain control over his life.
"Patients and their physicians often feel like they come to dead ends in terms of treatment," said Krishna. "We needed a new, single-use intervention that is less invasive and more effective."
What is Focused Ultrasound?
The incisionless procedure uses high-frequency ultrasound waves to inactivate the area of the brain that are involved with seizures.
The two-hour-long procedure is conducted in small increments to allow the research team to monitor the structure of the brain using magnetic resonance imaging (MRI) while undergoing ablation. A collaborative team of neurologists, surgeons, and psychiatrists are called in to plan, execute, and monitor treatment.
In 2023, Krishna described the initial experiences from a pilot, open-label, single-center clinical trial involving two patients with treatment-resistant epilepsy. The paper, published in Epilepsia, the highest and most esteemed journal on epilepsy, revealed that seizure frequency reduced significantly in both patients and did not result in severe adverse events.
On October 14th, 2025, Carr stepped into a large MRI room at UNC Hospitals. Krishna, Liu, neuropsychologist Matthew Harris, PhD, ABPP-CN, and other specialists were in attendance to check vitals and perform cognitive tests in between MRI scans.
Krishna and other specialists preparing Thatcher for his focused ultrasound ablation trial. Credit: Debbie Carr.
Carr was brought into the MRI a total of twelve times, with wife Debbie standing by anxiously - and a bit an awe.
"The energy in the room was palpable," said Debbie. "It became a jovial and very fascinating thing to watch. After all we have been through, it was such a relief to know that this could provide some real results."
After an overnight stay at the UNC Hospitals, Carr was cleared to go home and rest. It was an experience that he and his wife will never forget. And they usher other people with difficult-to-treat epilepsy to take part in similar trials to help advance new treatments.
"Don't be afraid to participate in a study such as this," said Carr. "I mean, yes, it's volunteer based, but you know what? Who's going to benefit the most from it? One, possibly yourself. Two, thousands of other people who are going through the same thing."
If you or a loved one is suffering from treatment-refractory focal onset epilepsy, make an appointment with one of our neurosurgeons by calling 984-974-4175 to schedule. To learn more about the clinical study, click here.
