BY EVE JACOBS
Surgery is currently the only possible way of curing epilepsy, but each year just 3,000 to 4,000 of the more than 2.5 million epileptics in this country are candidates. The rest must be managed with anti-epileptic drugs intended to prevent seizures.
Why? The answer lies both in the variety of complaints that are collectively called epilepsy and also in the biases of the physicians who treat it, according to epileptologist David M. Treiman, MD, chair of neurology at UMDNJ-Robert Wood Johnson Medical School.
Epilepsy refers to a recurrent pattern of seizures brought on by electrical misfirings in one or several parts of the brain. The causes are varied. Only about 20 percent is thought to be genetic, with the age of onset generally between 5 and 15. Other major causes include damage to the brain in the prenatal period or during birth, brain tumors, head trauma resulting from accidents, infections such as meningitis, as well as strokes, especially in older patients.
Treiman says the goal of treatment is to make patients seizure-free without side effects, so they can live normal lives. He states that in half of all new cases seizures are easily controlled by drugs; in one third, seizures are difficult to control by drugs but a physician with expertise can do it, sometimes at the cost of significant side effects; and that in one sixth, seizures are resistant to the standard medicines and will continue.
"These are the obvious candidates for surgery, along with patients for whom the side effects from medication are devastating," says the epileptologist. Treiman thinks that epilepsy experts should be "looking for patients who are curable," rather than viewing surgery only as a last resort. The drawback, he explains, is that most epilepsy does not affect just one part of the brain, but is "multi-focal," or affects several areas simultaneously.
"'How many bad spots can you cut out of an apple and still have an apple worth keeping?' is a graphic way to explain why surgery is often not an option," he remarks.
Treiman believes new approaches to finding a cure may yield results in the early part of the 21st century, including "magic bullet" therapy such as that in development for cancer in which anti-seizure agents could be directed only to those nerve cells responsible for seizures. "Just suppose that we could squirt a cytotoxic agent attached to an antibody into a vein, and it could cross the blood-brain barrier and seek out epileptic neurons," he comments.
Genetic engineering is another. He says that at least two different genes implicated in heritable forms of the disease have been identified, but this has not yet led to a better understanding of the disease process. "There are a lot of different gene mutations associated with epilepsy," he explains, "but the potential for a cure is there as it is in many other diseases."
Among the more speculative approaches but one he thinks has great promise is the implantation of genetically engineered cells that would release inhibitory neurotransmitters at times of high excitation into affected areas of the brain. This, in effect, would shut down a seizure before it really got going. "It may seem unattainable," says the epilepsy specialist, "but I think we might see it happen in my lifetime.
"This is a particularly promising time for epilepsy treatment," states the physician. Although there were no new drugs developed for this disease for 15 years, several new medications have been released within the last four years. "In some cases these drugs have fewer side effects; they may be easier to use for some people; and for others, they are more effective," explains the epileptologist.
"None of them is a wonder drug," Treiman concludes. "But the more drug possibilities we have in the arsenal, the greater the chance that we can help those whose seizures are difficult to control or who have serious side effects until the not-too-distant future when one of the new approaches to a cure becomes a reality."