Doctors at CARE Hospital, Hyderabad, have performed a rare invasive epilepsy surgery on a 27-year-old patient who had been suffering from seizures from his childhood. He used to get as many as 10 seizures a day. He tried a variety of anti-epileptic medications with no effect, but developed adverse effects from medication, including cognitive slowing, drowsiness and psychomotor retardation.
This is for the first time that an invasive surgery of this kind to remove the portion of the brain triggering seizures was performed on an epilepsy patient in Andhra Pradesh. Sree Chitra Thirunal Medical Institute, Thiruvananthapuram, is the only other hospital that had performed this operation in the country.
According to Dr J M K Murthy, who headed the operation team at CARE, the patient underwent Video-EEG, which revealed left anterior interictal epileptiform activity between seizures. The seizures revealed activity on both sides and could not be localized by scalp EEG (electro-encephalogram).
As MRI and scalp EEG could not pinpoint the source and location of seizures, intracranial electrode placement was done. This involved taking the patient into the operation theatre and placing strips of electrodes through a hole made on the left side of the skull. Five strips of electrodes were placed in different regions of the brain to scan the source of the seizures.
Dr Murthy said Video-EEG was repeated and the seizures recorded. The interictal activity now predominantly came from the parietal region and the seizures also came from the same region. After the seizure causing area was identified through the use of intracranial electrodes, the patient was operated and the cyst excised with the removal of the seizure-producing zone in the parietal region.
The patient did not show any post-operative neurological problems and is now completely seizure free.
The operation costs about Rs 2.5 lakh, including the cost of the imported electrodes between Rs 20,000 and Rs 25,000 a piece. Dr Murthy said that only doctors with experience and special training could perform this operation. Tinkering with brain could result in major complications to other parts of the body, including paralysis. Brain was a very sensitive organ and should be handled only by specialists, he said.
Who are the patients benefited by surgery? Patients who could not get any relief after appropriate drug therapy for over a year would require surgery. For every 100 patients, at least 20 patients fail to respond to the presently available anti-epileptic drugs. In India six out of 1,000 population, suffer from epilepsy. That means six million people out of a total population of one billion suffer from this disease. Of this 1.2 million people with epilepsy will be candidates for possible surgery.
Non-invasive surgery is commonly performed on patients who fail to respond to medication. By far the most widely used epilepsy surgery is temporal lobectomy. This involves removal of the portion of the brain near the temple. This is usually performed for an epilepsy syndrome called Mesial Temporal Sclerosis. The success rate varies from center to center. But complete control of seizures has been reported in 75 % of t6he cases and worthwhile improvement is seen in up to 90 % of patients undergoing surgery of this syndrome.
There are other types of surgery for different types of epilepsy - removal of cortex (surface of the brain -topectomy), removal of hemisphere ( one half of brain - hemispherectomy), separating the two hemispheres by cutting the connecting fibres, corpus callosum (corpus callosotomy) and making vertical transactions through the cortex ( multiple subpial transactions).
According to Dr Murthy, the most important element in the successful outcome of epilepsy is accurate identification of the origin of the seizures. The ideal surgery should destroy only the brain region responsible for the generation of the seizure.