Like many teenagers, Danielle Holton's first car was a ticket to freedom. At age 17, she bought a used Hyundai wagon from her mom, paying for it with money from her job as a certified nursing assistant. Danielle drove her car to classes at the University of Utah, work, and anywhere else she wanted to go.
But driving—and her sense of freedom—changed drastically when Danielle was diagnosed with medically intractable complex partial epilepsy less than two years later. The long name of her seizure disorder translates to Danielle still experiencing multiple types of disruptive seizures, even while taking medication.
Danielle began suffering from seizures around age 11, although it took nearly a decade to discover her condition.
As a child, Danielle loved being outdoors, hiking, camping, and visiting national parks with her family. It was on one of those trips that Danielle and her family experienced a severe car accident. Their pickup truck was hit head-on by a drunk driver, rolling down a hill and leaving Danielle with head trauma. At the time of the crash, Danielle was treated and released, but her treatment team believes her injury at the time may have contributed to the onset of seizures just months later.
A self-described overachiever, Danielle remained physically and emotionally active throughout her adolescence, scoring straight As in school and reading sets of encyclopedias to fuel her voracious drive for knowledge. But something wasn't right. Danielle recalls "absence seizures"—short periods of time when she would seem to stare into space, losing awareness without memory of what occurred. Always fiercely independent, Danielle hid these events from her parents and friends, learning to deal with them and make up for lost time in class.
As Danielle got older, the frequency and intensity of her seizures started to increase, gradually leading into classic grand mal seizures. Danielle knew she could no longer brush off her condition and sought medical help with the encouragement of her family.
"The diagnosis wasn't a surprise," explains Danielle, who was eager to start treatment right away. "But my self-perception really shifted. I still wanted to be a smart person and do things on my own. I still wanted to be myself."
With her condition now officially named, Danielle could no longer drive. But she was still determined to maintain her independence as much as she could. Danielle finished her college education taking the bus to school, continuing her work as a CNA, and beginning a career as a medical technologist. Danielle eventually married and had children, managing her condition by working from home and training her children to call paramedics when they witnessed a seizure.
Danielle's care team initially treated her with targeted medication and, later, a seizure-control procedure known as vagus nerve stimulation (VNS). This well-studied option has been around for decades and helps control seizures with a small pacemaker-like device that sends regular stimulation signals to the vagus nerve in a patient's neck.
Even with years of ongoing treatment, Danielle still experienced several seizures a week. At one point, Danielle was taking four different medications to combat her seizures. These medicines left her feeling tired, grumpy, and discouraged.
"I felt trapped in my own house," Danielle says. "I wanted to be able to run around with my children, and now grandchildren, without being worried or having them worry about me. I wanted to free them from caring for me, and really… free myself."
Dr. Angela Peters, a specialist at University of Utah Health's Clinical Neurosciences Center, began working with Danielle in 2015. As Danielle and Dr. Peters consulted together, Dr. Peters immediately recognized Danielle as a candidate for a revolutionary procedure called Responsive Neurostimulation (RNS). Like Danielle's previous procedure, RNS uses a type of pacemaker. But this one is implanted in the brain to specifically target one or two areas where the seizures originate.
Another ground-breaking aspect of the RNS device is its capability to monitor, record, and respond to irregular brain signals that cause seizures. The device is programmed through a complex set of parameters determined by Dr. Peters and the bioengineers behind the device. Dr. Peters reviews and analyses monthly data returns from a patient's device, making program adjustments as needed. Remarkably, devices learn to anticipate and detect seizure activity on their own.
"Most patients with intractable epilepsy, like Danielle, have a surgical option to treat their seizures when medication is not enough," Dr. Peters explains "RNS offers an alternative to traditional resection (brain tissue removal) to treat seizures. We work with patients to learn about frequency and symptoms before, during, or after a seizure. Once we understand a patient's history, we have good clues about where the seizures are coming from."
This procedure seemed like Danielle's new road to freedom, but there were still obstacles to overcome before moving forward. Qualifying for RNS can be an arduous process. Patients undergo a litany of tests, including extended hospital stays and long-term EEG testing. These tests help doctors get to know the patient's brain and determine if seizures are coming from the same area each time they occur.
For Danielle, the lengthy testing process was worth it. "My goal was to go more than three weeks without a seizure," she says. "I was ecstatic for the chance to be seizure free."
Even the idea of intricate brain surgery didn't deter Danielle.
"I clung to hope that the procedure would work," she says. "I didn't want to go through any more. The idea of dealing with seizures for the rest of my life was more terrifying than any surgery."
Danielle met Dr. John Rolston, U of U Health's director of epilepsy surgery and stereotactic and functional neurosurgery, in December 2017 as she came to the end of her diagnostic workup. At this point, Dr. Peters and the rest of Danielle's treatment team had made significant progress in pinpointing the specific brain locations (foci) of Danielle's seizures. But more evaluation was required to confirm foci with exact accuracy before surgery could take place.
Dr. Rolston performed a stereo-electroencephalography (SEEG) procedure, implanting spaghetti-sized electrodes in Danielle's brain to verify precise foci. Once this information was gathered and Danielle's team was confident in the best areas to access in order to halt her seizures, Dr. Peters and Dr. Rolston defined Danielle's procedure, giving her the option to move forward with RNS as soon as she was ready.
After years of testing, it felt like "game day," remembers Danielle. Dr. Rolston used mini-robotics to precisely implant electrodes inside Danielle's brain. These electrodes connect to the RNS device, which is enclosed in a titanium plate in a section of Danielle's skull. Despite the complexity of the procedure, recovery time for most patients is only one or two nights, with minimal side effects that diminish over time.
Danielle underwent surgery in April 2018. At her post-operation appointment with Dr. Rolston a month later, she was seizure-free. "Sometimes I think, 'Do I really have epilepsy?'" Danielle says. "I can go out in my yard and garden. I haven't had to call in sick to work because I've had a seizure. My daughter and I can go ride bikes together, which was something risky to do when I was having seizures. My older kids ask me to babysit and care for my grandkids more often. I can be myself again."
As Dr. Rolston explains, "Patients have seizures we can see and that they notice, but they also have sub-clinical seizures. Those events don't allow the brain to function at full capacity. So fewer seizures optimize brain function—patients feel like themselves."
According to Dr. Peters and Dr. Rolston, most patients implanted with an RNS device experience a 50% reduction in seizures. One out of three patients will see greater than 90% reduction, and 18% will go one or more years without a seizure. Since the launch of RNS devices nearly eight years ago, the median reduction of seizures for patients is 75%.
"This is a quality of life improvement," Dr. Peters says. "Danielle is seizure-free, but she also doesn't have the same anxiety, fear, and depression that she had before. Similar to Danielle's case, the average time between a patient's diagnosis and a procedure like this is around 20 years. We want people to know they don't have to wait that long. It takes commitment, but change is possible."
This spring marks two years since Danielle's procedure to implant RNS, and two years without a seizure. She's made the return to being outdoors. Danielle is hiking more often and looks forward to a trip to southern Utah to tackle the trails with newfound confidence.
Perhaps in the years to come, Danielle will even drive herself there.