Electronic implant might stop seizures

It hit Haley Butler while she was driving - an odd feeling like dj vu. Then her right hand started tingling and began twirling around on its own.

 

"I couldn't stop my right hand," said Mrs. Butler, of Ideal, Ga. "I knew the radio was on. I could hear the music, and I understood the songs. But I couldn't get (the words) out."

She reached her mother's house.

"I was hyperventilating; I just couldn't quit crying," she said.

She was having seizures from a form of epilepsy that appears to affect the language area on the left side of the brain.

"I can talk now while I'm having it; it just doesn't make sense," she said. "I actually try talking, and it's just a bunch of gibberish."

Medication couldn't stop the seizures - particularly bigger grand mal seizures - she would have in her sleep. And because the epilepsy focal point appears to be in the language area, she wasn't a good candidate for surgery, said Yong Park, a pediatric epileptologist at Medical College of Georgia.

But she was a candidate for an experimental implant called the RNS System from NeuroPace. The small electronic stimulator is powered by a battery implanted on the surface of the brain.

A seizure is an abnormal simultaneous firing of neurons, and for many patients this firing follows a distinct pattern and originates in the same spot, said Gregory Bergey, the director of the Johns Hopkins Epilepsy Center and vice chairman for neurological laboratories in the Department of Neurology.

"It's almost like a fingerprint of that seizure for that person," Dr. Bergey said. "You can tune a very simple computer chip to accurately detect seizure activity and detect it very early."

Most seizures last a couple of minutes, so the hope is that detecting a seizure and interrupting it early on would keep it from building and causing symptoms for the patient, Dr. Bergey said.

"In the brain, what you're trying to do is put a low-intensity current and disrupt this natural 120-second evolution of activity and make it end earlier," he said.

The device is connected to leads placed near the focal or trigger point for the seizures in the patient's brain. The device can detect the abnormal storm of electrical activity that signals a seizure, then deliver short bursts of electricity to keep it from spreading and causing symptoms. It is only for patients who have a clearly defined focal point for their seizures because doctors have to place the leads within a few centimeters of the spot, Dr. Park said. The focal points can't be too large either or the device won't be able to block it, he said.

An estimated 1 percent of the U.S. population, or 3 million people, are treated for epilepsy, the Epilepsy Foundation said. For about one-third, medication either doesn't work or the side effects are too severe. For those who can't or won't seek relief through surgery, it gives doctors another option, Dr. Park said.

As with many epilepsy treatments, the scientific process with this device is backward, Dr. Park said. Doctors are able to achieve a result and then must go back to find out why it is working.

"The underlying mechanism is not clear," he said.

The electrical impulses from the device might jam the networks the seizure spreads out on. Or, by stimulating at the right time, the devices might be alleviating the conditions that cause the seizure. MCG was one of the first sites to study the safety of the device and is one of 28 across the country testing its effectiveness. Dr. Park is the principal investigator at MCG, and Mrs. Butler was the first patient to get implanted.

The device can record electrical activity, which leads to a surreal scene for Mrs. Butler. Every night, she holds a device up to her head that downloads the recorded activity to a laptop.

"It sends all of my brainwaves to California, I think, I'm not sure, to a research study," she said during a recent visit to MCG. "So they know all of my brain activity before I even get into this office."

During her visit, neurologist Anthony Murro tries to fine-tune the electrical impulse so it will work without Mrs. Butler feeling it. "You tell me if you feel anything," Dr. Murro said, fiddling with the laptop programmer.

"I feel a little bit in my left eye," Mrs. Butler said.

"Now?" he asked.

"No."

This is just the latest adjustment for Mrs. Butler and her husband, Steve.

"I haven't driven in four years because of the seizures," she said. There are other, deeper marks the seizures have left on her.

"I've lost a lot of memory since my seizures," Mrs. Butler said. "I lost a lot of my memory from high school. I can remember the smallest little detail of something that shouldn't make a difference to me, yet I can't remember going through ninth through 12th grade. I've lost the memory of one of the closest friends I ever had. So it's taken a big toll on me."

Since getting implanted in the spring, she has gone from 13 seizures a month to three, and sometimes she goes a couple of months without one.

"The biggest adjustment I've made since then, since the implant, is just trying to keep a positive attitude," she said.

That's the point, Dr. Park said.

"The quality of life issue is very important," he said.

Reach Tom Corwin at (706) 823-3213 or tom.corwin@augustachronicle.com.

PATIENTS SOUGHT FOR STUDY

Medical College of Georgia is now enrolling patients with certain kinds of epilepsy into a clinical trial to test the implantable RNS system from NeuroPace (left). To be eligible, patients must have:

- Disabling simple partial seizures, complex partial seizures or secondarily generalized seizures

- Three or more of these seizures a month

- Failed to get relief from at least two epilepsy drugs

- Seizures that have no more than two focal points

The trial is open to those ages 18-70. For more information, call (706) 721-6260.