`Surgery can cure epilepsy'

M. VEDHAN

Interview with Dr. Mecheri B. Sundaram, Director of the Neurophysiology Laboratories at the Epilepsy Centre in the University of Mississippi Medical Centre, United States.

Dr. Mecheri B. Sundaram, Director of the Neurophysiology Laboratories at the Epilepsy Centre in the University of Mississippi Medical Centre, United States, has received training at various medical centres across the world, including the neurology departments of the Universities of London, Newcastle upon Tyne (England) and Ontario (Canada).

Dr. Sundaram is trained in internal medicine, neurology and clinical neurophysiology. His clinical interests are epilepsy, electro-encephalography (EEG), evoked potentials and intra-operative neurophysiological monitoring. His current research interests include pathogenesis and early prediction of intractable temporal lobe epilepsy and epilepsy in the elderly.

Chairman of the Canadian EEG Society and Director of the Southern Epilepsy/EEG Society, Dr. Sundaram was chairman of the Canadian Society of Clinical Neurophysiologists (EEG Section, 1990-92); a Council member of the Canadian Society of Clinical Neurophysiologists (1990-92); and an examiner of the Canadian Society of Clinical Neurophysiology (EEG examinations, 1992-93). He is a Director of the Canadian Board of Registration of Electroencephalograph Technologists.

Dr. Sundaram has published extensively in The Journal of the Neurological Sciencesand Neurology as also for the University of Louisville (Neurosciences grants) and the British Columbia Health Research Council.

A recipient of the R. Samuel McLauglin Fellowship at the University of Western Ontario, he has won the Best Teacher Award in Neurology for 1995-96, 2000-01 and 2003-04. He has been listed among the "Best Doctors in America" since 2000.

He was in Chennai to deliver the 5th Appa Rao Endowment Lecture on "An approach to the patient with intractable epilepsy", organised by the Neurosciences India Group and the Madras Institute of Neurology. Dr. Sundaram spoke to Asha Krishnakumar on the various forms of epilepsy, its causes, diagnosis, management, treatment and cure. Excerpts:

What is epilepsy? What are its symptoms?

It is one of the commonest diseases of the brain. The brain cells, from time to time, produce unwanted excessive discharge that lasts a few seconds - maybe a few minutes, sometimes longer - and that is called an epileptic seizure. A symptom of epilepsy is a bout of seizures.

Why does this happen? What are the different types of epilepsies?

It happens because of a neuro-chemical imbalance in the brain cells. For some, it happens in one area of the brain and in others it affects the whole brain simultaneously. So there are different types of epilepsy.

What is the incidence of epilepsy?

It is a very common problem. Nearly 1 per cent of the population has epilepsy. In medical statistical terms, it is a very common disease. This is true anywhere in the world. But, according to some statistics, epilepsy is probably more common in developing than developed countries.

Why is epilepsy more common in the developing countries?

Because there are some unique causes of epilepsy such as cysticercosis (a disease caused by a parasite that enters the brain and causes a chemical imbalance) that are common in developing countries. But the bottom line is that it is a very common disease.

What are the common causes of epilepsy?

Something may go wrong at birth - maybe the process of labour is difficult, maybe the brain cells do not get enough oxygen - that over time may produce scar tissue. This, in turn, will produce seizures and epilepsy. Infections from bacteria or viruses may produce a similar kind of scar tissue, which leads to epilepsy. A brain tumour can cause epilepsy. As you get older, stroke can cause epilepsy. Trauma, a major head injury, can cause epilepsy.

Having said all that, according to statistics, two-thirds of the time there is no apparent cause. This is called idiopatic or unknown. The unknown situation is not that uncommon. But even in these cases, we look for causes. But in all these things epilepsy is the final manifestation. It is quite complex - so many things lead to the same result, just like how brain bleeding, migraine and several other things cause headache, so too, all these different processes lead on to the same symptom.

What are the common symptoms of epilepsy?

The most common one is you lose consciousness. You fall, your body gets stiff and you may have spasms. Those are the major symptoms every one is aware of. However, that is only one type of epilepsy. There are other types. For example, sometimes, you stare into space, you fumble with your hands and somebody talks to you and you do not respond. This is a relatively minor type of epileptic seizure. Earlier one is the grandmom. That is the one we all see and are scared of.

But there are other symptoms. For instance, there can be those who do not respond for one or two minutes and stare into space from time to time. Now, that could be an epileptic seizure. People should be on the alert for such symptoms.

Sometimes you get a warning signal at the beginning of a seizure. For example, you get a funny taste for no reason, you perceive a funny smell, a strange sensation goes up your body and so on. In medical terms they are called `aura'. Some people have warning signals and some do not.

What are the diagnosis methods for epilepsy?

The first thing a doctor should do is to get a detailed history to confirm epilepsy because a lot of different things can produce some of those symptoms. So you should not diagnose yourself. You need to go to a neurologist.

The common test is the EEG, a brainwave recording. What we look for are abnormal telltale signs. The patient does not need to have a full-blown seizure but even in a 20-minute brain testing you can pick up the abnormal signals. That helps the doctor diagnose the condition.

Very often a magnetic resonance imaging [MRI] scan of the brain is done. It is expensive, but it is important not to miss a small brain tumour, which no other test will show. So the EEG reveals the functional or the physiological abnormality, MRI picks up the structural causes. Both are supplementary and needed.

What are the treatment options for epilepsy?

We have about 10 medications available now. The majority of them have come into the market in the last 15-20 years. Phenobarbatol and Phenetoin are the old medicines. But in the last 15 years we have nine new, more effective medicines with few side-effects. So, it is easier to treat now than what it was some 20 years ago. Despite all these medicines, about 40 per cent of all people with epilepsy are intractable, that is, they continue to have seizures. They may hurt or injure themselves. Once you have a seizure, you cannot drive, you get depressed and you get anxious. So there are a lot of psycho-social issues that are common in these people. We do not talk about all this. Patients do not very often talk to the doctor about it. But help is often available. There is no reason to cover up your disease. It is a common problem.

Epilepsy is still a stigma. People do not want to talk about it...

Yes. It is. Basically, what is an epileptic seizure? Owing to a viral infection you get cold in the nose. If you get a viral infection in the lung, you get pneumonia. Similarly, if something goes wrong in the brain, you get a seizure. It is as simple as that. There is nothing bad about having a seizure. That is the way brain disorders declare themselves. You are not any inferior just because you have epileptic seizures compared to, say, somebody who has a fracture of the leg. That is the nature of the disease. People should understand that.

Does the incidence of epilepsy vary across age, sex and ethnicity?

It may be slightly more common in males. But the difference is not major. It affects anybody. It starts in childhood or in middle age. In fact, as we get older, we see more and more people developing epilepsy for the first time after 60. The prevalence of epilepsy is more common in the older age. It is going to be one of the most common disorders of man in the next few decades. And, as the life expectancy at birth increases, the problem is also going to rise.

What is the relative importance of genetic and environmental factors in causing epilepsy?

Genetic disorders are recognised as a cause of epilepsy. It is probably responsible for 5-10 per cent of epilepsy. But there are a whole bunch of other factors. Sometimes it runs in the family. But it is different from muscular dystrophy, for instance, which is a genetic disease. Epilepsy is not that genetic. There are other reasons one must look for. There are probably environmental factors underlying epilepsy, but we do not quite understand them.

What is the state-of-the-art in epilepsy diagnosis, treatment and research?

There is a lot of research in finding new medicines. A lot of drug studies are being done. Some exciting things are happening in drug discovery. You can actually screen the drug very quickly. We are trying to understand a lot of molecular problems that go wrong and cause epilepsy. For instance, there may be some problems in the sodium, potassium or calcium channel. Now, we can actually take a chemical picture of those channels, compare them with normal ones and find out what happens when someone has epilepsy... what goes wrong and how we can fix the chemical hole in the channel. We are in the process of manufacturing specific drugs that repair the specific damage.

So we can now, with a specialised EEG, predict when an epileptic attack is going to happen even one or two hours ahead of the attack. One group of scientists is working on making a drug pump, just like an insulin pump for diabetes, attaching it to the brain and directing the drug to the abnormal area. So when an epileptic seizure is imminent, the pump automatically sends the medicine and aborts the attack. These are all in the pipeline, for the next 10-20 years.

Another common, under-utilised treatment is epileptic surgery. When medicines do not work, surgical treatment can cure epilepsy in a good majority of the people. It is standardised but the access may be limited because only a few centres do the surgery. The knowledge about the availability (of this option) is also not there. However, it is beginning to happen in India, although on a limited scale. It is as safe as any other brain operation. There are tests and procedures you do to make sure that you do not get into any difficulty because of the surgery.

Is there an age limit for the surgery?

There is no age limit. We do the operation even at the age of 70 because the person may have another 10-15 years, with the rising life expectancy. But it is better to catch them early. You do not need to have seizures every month for 20-30 years and then go in for surgery. You need to have a much better quality of life, so tackle it early. The lack of knowledge about the availability of specialised treatment options is an issue anywhere, not just in India.

How expensive are the treatment options for epilepsy?

There are some very cheap drugs. For instance, Phenobarbatol, a good old drug that costs one cent a tablet [in the U.S]. But some of the newer medicines are expensive, from $2 to $5 (Rs.90 to Rs.225, approximately) a tablet. On an average, a person takes two or three pills a day. It is also a lifelong treatment.

Do the more expensive drugs have fewer side-effects?

Not necessarily. They are medicines on whose development the drug companies have pumped in millions of dollars and they want to get their money back.

Has the number of people with epilepsy been rising over time?

The numbers seem to be increasing, probably for two reasons. People are living longer so there are more people with epilepsy. And, with the Internet, the dissemination of knowledge about the disease is rising. For instance, somebody who had never thought of the disease but who had it all along is now going to the doctor. This also shows up in increased numbers. That, of course, applies to any disease. Also, the ascertainment methods are improving too. This is primarily because the epidemiological research is much more sophisticated now than it was 40 years ago.

What are the epidemiological studies in different countries showing up?

Recent epidemiological studies show that if you compare studies done in South America, Sub-Saharan Africa and India with those done in Norway or Sweden, it looks like the incidence is perhaps more in the former countries. These studies are beginning to give us an understanding of the different causes in different parts of the world, which appear to vary.

Is the stigma attached to epilepsy there in all countries?

The level of stigma varies. But it should really not be there. With some limitations such as you cannot drive and so on, an epileptic can be as normal as anyone else. Epilepsy is like any other disease. Help is available. There are a lot of new drugs. Surgery, which is standardised, is an option. You just have to seek help.