HEALTH

Prescription for hope

New drugs can help many epileptics lead normal lives

LUKE FISHER July 10 1995
HEALTH

Prescription for hope

New drugs can help many epileptics lead normal lives

LUKE FISHER July 10 1995

Prescription for hope

New drugs can help many epileptics lead normal lives

HEALTH

When he was 10 years old, Michael Duffett dreaded going to school. His classmates, aware that he suffered from epilepsy, would tease him mercilessly, calling him “Fitso” and taunting him until he lashed out in explosions of temper. And that was only one of many epilepsy-related problems that held Duffett back at school and tied him inextricably to his home in Bonavista,

Nfld. Over the years, Duffett endured thousands of seizures and a seemingly endless series of drugs, many with unpleasant side-effects. But since he began taking one of three promising new drugs for epilepsy in late 1993, the seizures have stopped—and he has been able to start rebuilding his life. “It’s been my miracle,” says Duffett, now 25. “Now, I can go where I want to, when I want to.”

The new drugs—Vigabatrin, Lamotrigine and Gabapentin—finally give Canada’s 280,000 epileptics hope for more normal lives. Epilepsy is the most common neurological disorder after headache, affecting more than one per cent of the population. It has been little understood until this century, and its stigma—associated with past fears of demon possession—remains powerful. A seizure can indeed be a disturbing experience to watch.

But it is even more distressing for epileptics themselves, some of whom do not even tell their employers about their condition because they fear a negative reaction.

Likened to an engine misfiring, the onset of a seizure can be either partial (restricted to one area of the brain) or generalized (affecting the entire brain). Caused by a sudden overload of electrical activity related to excessive discharges by nerve cells, its symptoms range from something called the aura—a peculiar sensory phenomenon, often accompanied by a sensation of déjà vu—to loss of consciousness and violent muscle contractions. When used with other anticonvulsants, the new drugs can reduce seizures far more effectively than older drugs, with fewer side-effects. Dr. Alan Guberman, professor of medicine at the University of Ottawa and director of the epilepsy clinic at the Ottawa General Hospital, says that repeated studies have shown the new drugs to be effective. “In the past, some patients responded to nothing,” said Guberman. “But now they can even be seizure-free.” Approved by the federal Health Protection Branch last February, Lamotrigine is made by North Carolina-based Burroughs Wellcome

Inc., and is effective across a broad spectrum of seizures. It works by reducing the release of excitatory amino acids in the brain, especially glutamate. Gabapentin, approved a year earlier, is manufactured by Michigan-based Parke-Davis. Although research into how Gabapentin works is inconclusive, it appears to alter nerve cell metabolism, cutting the frequency of seizures in half for as many as 30 per cent of patients. The drug that has liberated Duffett—Vigabatrin—increases the brain concentration of GABA, an inhibitory neurotransmitter, and is more effective than the other two drugs for partial-onset seizures.

Still, the long-term effects of the new drugs are not entirely known. The man who oversaw Vigabatrin’s development, Dr. John Mumford of the German pharmaceutical giant Hoechst Marion Roussel, cautions that although studies looking into side-effects are being

conducted around the world, epilepsy drug research is necessarily slow going. Because each brain is slightly different biochemically, seizures manifest themselves in seemingly countless ways. As a result, dosages may vary widely, and a drug that is suitable for one patient may not be for another. “You can never know all about a drug,” says Mumford.

Duffett, who in the past found the sideeffects of drugs as debilitating as his seizures, has experienced none since taking Vigabatrin; other users of the medication have reported drowsiness. For those on the other two drugs, the known side-effects are also rare—possibly a skin rash with Lamotrigine, and fatigue and nausea with Gabapentin. More worrisome, according to Guberman, is expense; the new drugs cost twice as much as previous treatments, and monthly bills can be as high as $300 or more. “The price is unreal,” says Marion Shannon, whose epilepsy began 18 years ago after she fell down a flight of stairs. Until she started taking Gabapentin last January, Shannon, 45, a former nurse from Halifax, had averaged 24 seizures a month. Now, she is seizure-free—and says that the drug is worth the cost. “It has changed my life 100 per cent,” says Shannon, who recently decided to get back into nursing. “I am able to function again as a human being.” But for people with partial-onset epilepsy who do not respond to medical therapy, an effective alternative can be brain surgery. Since the groundbreaking work of Dr. Wilder Penfield in the 1920s, surgeons at the Montreal Neurological Institute have gained a worldwide reputation, improving their technique to the point where, during a procedure in

0 which the patient remains con-

1 scious, the affected part of the brain g can be removed. While the majority s of patients see substantial improvement, for those averaging a seizure per week there is a 35 per cent chance of being fully cured. Although he is impressed by the new drugs, Dr. Joseph Bruni, head of neurology at Toronto’s Wellesley Hospital and a leading authority on epilepsy, also recommends surgery for properly screened patients. “For them,” he says, “surgery has a better chance of eliminating seizures.”

As 14,000 new cases of epilepsy are diagnosed in Canada each year, medical research continues. But Mumford says scientists should be looking for more than simply a treatment— and hasten the search for a cure. Most promising is DNA testing, which may lead to a cure by identifying the mechanism by which seizures might begin. “Epilepsy is the symptom, not the disease,” Mumford says. And for those whose seizures continue despite the new drugs, a cure cannot come soon enough.

LUKE FISHER