Lisa Robison, a 49-year-old Duluth mother of a grown son, has suffered complex partial seizures since she was 6 years old. Over the years, she has tried many medications and was part of numerous studies. Yet, the seizures would not be controlled.

Desperate for help, she jumped at a chance seven years ago to participate in medical trials for the NeuroPace RNS System, a tiny, pacemaker-like device designed to reduce epileptic seizures and lessen their severity.

"I thought I would try it," Robison said.

"It has helped me," she said. "I don't fall as often. Or get injured. My seizures are shorter, and I recover faster."

The device has helped Robison and more than 200 other patients across the United States, and now others who suffer from focal epilepsy — epilepsy that originates in one or more specific areas of the brain — may be candidates for the NeuroPace device. Two years after implant, nearly 60 percent of patients had their seizures cut by more than half.

NeuroPace said an estimated 400,000 patients in the United States could benefit from the technology.

"All the evidence we have indicates that there is a substantial improvement in the patients' quality of life," said Frank Fischer, NeuroPace CEO.

Mayo Clinic facilities in Arizona, Florida and Minnesota all were involved in the clinical trials for the device and, as a group, enrolled the highest number of patients in those trials. The U.S. Food and Drug Administration in November approved the system for commercial availability in the United States. NeuroPace, a private California company that has worked on the technology for 16 years and raised more than $216 million in venture capital, is now working with hospitals and insurance companies to ramp up the device's availability.

"Technologically, this is really a huge step forward," said Dr. Gregory Worrell, a neurologist with the Mayo Clinic in Rochester.

"This is no longer research. This works," said Dr. Joseph Sirven of the Mayo Clinic in Scottsdale, Ariz.

Mayo Clinic receives research support from NeuroPace, and a Mayo physician, Dr. Richard Zimmerman, receives consulting fees as a member of the company's medical advisory board.

The Epilepsy Foundation said it "celebrates" that the system has been made available. "We badly need new, effective therapies," said Warren Lammert, chairman of the foundation.

How it works

Called a "closed-loop system," the NeuroPace device consists of a tiny, implantable generator that fits flush with the patient's skull and tiny wires that run to the surface of the brain. Electrodes detect and record abnormal electrical signals that lead to seizures; others deliver therapy.

"Most devices, you turn on and it goes at whatever rate," Sirven said. "With this device, electrodes are planted in the brain over the area where seizures are coming from. So this detects a seizure — then it sends out an electrical discharge to that area."

Use of the device does not eliminate the need for medication. But, for patients who have found little or no relief despite taking two or more medications, the device's success in trials is major news, Worrell said. An advantage of the device is that doctors can continually adjust it to better respond to what causes a patient's seizures.

"We are constantly tweaking it, a little bit here, a little bit there," Worrell said.

Worrell and Sirven said despite the device's success with many patients, those who suffer from epilepsy need to keep in mind that implantation of a medical device into the skull and brain is not without risk. "It is highly invasive," Worrell said. "And this is not for patients with generalized epilepsy, that is, seizures that start in both hemispheres of the brain."

Medical technology makers across the country, including Medtronic, are working to develop similar closed-loop pacemaker-like systems to treat everything from Parkinson's symptoms to essential tremor. Devices are being used to send a pulse to the brain to lessen symptoms, and researchers are trying to develop ways for that treatment to be delivered on-demand by reading a patient's brain waves.

A better life

Robison had her device, a rectangular generator about as thick as a couple of quarters stacked together, implanted on the right side of her skull at the hairline above her eyebrow. Doctors removed a small piece of her skull so the device would be flush with the bone and not make a visible lump. Two wires run from the device to the surface of her brain; one wire is implanted deeper into her brain.

The device does not always work. "But most of the time, it does," she said.

She jumped for joy when she heard the FDA had approved its use for others, "because now other people who have rare seizures can get help and I can continue on with it."

Fischer, NeuroPace's CEO, said the road to approval was long. But for many of the epilepsy patients getting NeuroPace's device — at an average age of 35 and having suffered seizures for 20 years — the result is satisfying.

NeuroPace has sold two systems since FDA approval but tracks 258 patients who have had it implanted. The system has multiple components. Depending on the components selected, the purchase cost of the full system is likely to be about $40,000. Fischer said NeuroPace continues to work with hospitals, Medicare, Medicaid and private insurers as it ramps up efforts to make the device available to patients.