Published: March 29, 2009 04:18 am      

Step one: Diagnose the problem

FAIRMONT — When Raven Orr was diagnosed with epilepsy last summer, she became one of up to 2.7 millions Americans with one or more forms of the neurological condition caused by sudden bursts of electrical energy in the brain.

A seizure is an event that involves loss of consciousness and motor (muscular) control caused by a sudden change in electrical activity in the brain. It may be symptomatic, or have a known cause, or idiopathic ... just one of those things that happen. In any case, it is not contagious and can occur in anyone at any age.

Step one is to diagnose the problem.

“To truly clinch the diagnosis for epilepsy, an EEG is required,” said Dr. Warren Boling, associate professor neurosurgery at West Virginia University. An electroencephalogram, or EEG, records abnormal electrical activity in the brain.

An EEG may be “a quick outpatient” thing, about 30-60 minutes long.

“That’s just a very small slice of time,” Boling said. “So you may not see abnormal activity of a true seizure.” Or it may last for several hours, allowing more opportunity to record abnormal activity.

“Many patients still have convincing spells, but we’re not able to diagnose completely with an outpatient EEG. They may need to be admitted and have an EEG recorded over several days. Our goal is seeing one or several of the described events.

“Often this is the best way ... the only way ... to know for sure if the event is truly epilepsy or not.”

That recording may take place at the WVU Epilepsy Monitoring Unit, where patients are hooked up to an EEG and watched and any seizure activity recorded 24/7.

TREATING SEIZURES

The first step in treating a seizure disorder is usually through medication.

“Some are clearly shown to work better for certain seizure types,” he said. “That may guide the decision but many of the meds work equally well with other seizure types. It all comes down to which is better tolerated by the patient.

“All medications have side effects. But one medication may work for one individual and not another. That’s why it’s complicated. Choosing the medicine and adjusting the levels and dosage for the right combination, some of it is science but most of it is an art.”

Some relatively new epilepsy drugs include tiagabine, gabapentin, topiramate, levetiracetam and felbamate.

Unfortunately, for some, medicine doesn’t work.

“Studies have shown that once a person has tried and failed two or three standard epilepsy medicines, it’s extremely unlikely any new combination will control the seizure. They could spend the next decade trying every medication combination but it would not work. That fits the criteria for medically intractable seizure.

“Then that individual should be evaluated in a comprehensive epilepsy program that can do that chronic video EEG monitoring to characterize the seizure and look for additional options.

Intractable seizures can be “debilitating and dangerous,” he said. “This patient should be evaluated for additional treatment options, most commonly surgery.”

SURGERY

“A multidisciplinary teams meets weekly to evaluate patients for surgery, If everyone is convinced and it looks like a reasonable tool to help the patient and safe to accomplish, we recommend surgery to remove and disconnect the seizure focus in the brain.”

The most common form of epilepsy treated with surgery is “far and away temporal lobe epilepsy,” he said. “It’s not the big, shaking, convulsive seizure. It usually involves staring, loss of contact, chewing, fumbling that the patient doesn’t remember. Fifty percent get a warning (or aura) it will happen, But 50 percent do not. These can occur many times a day, weekly or monthly. The frequency varies.

“Worldwide for all epilepsy programs, these are the most common seizure treated with surgery. And for some reason, they are the most intractable with medicine. We expect 75-80 percent after surgery to be seizure-free. It’s quite a dramatic result.”

VAGUS NERVE STIMULATION

Kind of like a pacemaker for the brain, this is a palliative approach to seizure control.

“We do not expect to stop the seizures but to reduce their severity and duration,” Boling said. “When we evaluate a patient for surgery, we have to ask if this will give the patient a reasonable opportunity for a cure.”

A device is implanted under the collar bone, with a wire connecting to the vagus nerve in the neck. That nerve is part of the autonomic nervous system, which controls body functions not under voluntary control, such as heart rate. VNS works by sending regular, mild pulses of electrical energy to the brain through the vagus nerve.

It can reduce seizure frequency by about half and works equally well on all kinds of seizures, Boling said. Still, it’s not for everybody.

“It’s FDA-approved only for partial epilepsy, where the seizures originate from one spot in the brain. As far as we know, it works as well for generalized seizures (which originate from both hemispheres in the brain).

“And it’s expensive, about $15,000” he said. “But because it’s approved only for partial seizures, insurance companies will pay only for partial. That’s not something people can pay out of pocket.”

So you’ve got an expensive device that could cut intractable seizures in half but may not be covered by insurance. That’s when it’s time for “an earnest conversation” with the patient, Boling said.

“Is that a meaningful benefit? Most will say yes, but some will say no. We have to have that conversation.”

ADVANCES

While the gold standard in diagnosing seizure disorders (and for a while the only way) remains the EEG, new techniques are available.

“This is very exciting,” Boling said. “There are all new types of imaging modalities. It’s becoming really imaging-intensive.

“Our recommendation for individuals with newly diagnosed epilepsy is to have high-quality brain imaging, an MRI. This sees the brain in much more detail than a CT scan can.

“Many things can cause epilepsy,” Boling said. “You can be born with it or aquire it. It may even be caused by a tumor or other abnormalities of the brain that only an MRI can detect. An EEG may look the same for all causes.”

A new EEG development is a procedure called “solving for the inverse problem.” It’s kind of like “Jeopardy!” You know the outcome but not the cause.

“It uses a complex mathematical formula to calculate the origin of the electrical focus of the seizure,” he said.

This is used in dense array EEG, which improves on the standard EEG by using more “electrodes” (small saline soaked sponges that are able to record the electrical activity of the brain) for better accuracy and localization of the source of any abnormal electrical activity.

“It calculates for the source of the electrical dipole. All activity in the brain is electrical and electricity is dipole: positive and negative,” Boling said. “If you can identify the source of that dipole, that may help you in locating where the seizure originated.”

Magnetoencephalogram, or MEG, is an experimental type of brain scan that detects the magnetic signals generated by neurons to allow doctors to monitor brain activity at different points in the brain over time, revealing different brain functions. While MEG is similar in concept to EEG, it does not require electrodes and it can detect signals from deeper in the brain than an EEG.

“It’s solving for the inverse problem again, but recording magnetic activity, All electricity has the potential to be magnetic,” he said.

Doctors also are experimenting with brain scans called magnetic resonance spectroscopy (MRS) that can detect abnormalities in the brain's biochemical processes, and with near-infrared spectroscopy, a technique that can detect oxygen levels in brain tissue.

“There’s excitement today on two fronts,” Boling said.

One is deep brain stimulation, an experimental therapy in which a stimulating electrode similar to VNS is implanted in the brain. The implanted electrode precisely stimulates specific structures deep in the brain. FDA-approved the use for Parkinson's disease since 1997, it is not an accepted treatment for epilepsy at this time.

“The electrodes are passed to different targets deep in the brain to improve the symptoms of Parkinson’s,” Boling said. “DBS for epilepsy is old, more accurately, revived. It was attempted back in the ’60s and ’70s, but the technology wasn’t there that we have now. There has been a revived interest and enthusiasm because of the number of targets that can be looked to treat medically intractable seizures.”

Second is the use of microcomputers to predict the onset of a seizure and deliver “a little electrode impulse to reduce or stop it,” Boling said.

“All of this is in clinical trial,” he said. “It’s all coming down the pike. We’ve yet to see what impact they'll have, but we’re certainly enthusiastic.”

E-mail Debra Minor Wilson at dwilson@timeswv.com.