When is Surgery Necessary in the Treatment of Epilepsy?
There are approximately 300,000 Canadians who suffer from epilepsy and about 40% have seizures that are not well controlled by medication. Brain surgery may be an alternative and it's being used more and more often.
Improved technology has made it possible to identify, more accurately, where seizures originate in the brain, and advances in surgical techniques have made surgery much safer. As a result, doctors are turning to surgical intervention for those patients who qualify because there are some patients who don't respond to conventional drug therapy.
There are several reasons to consider this alternative. Many people face the prospect of a lifetime of ineffective drug therapy. They have become resistant to many antiepileptic drug treatments and their seizures have become uncontrollable. Surgery may become an option if the seizures have resulted from accidental injuries to the brain and scarring of the tissue. Mortality rates for some patients with complex partial and generalised seizures are far greater than those of the age-matched general population. They may also have severely compromised social, intellectual and professional functioning resulting from repeated seizures. Some of the common types of surgeries include: focal cortical resection, anterior temporal lobectomy, hemispherectomy, and corpus callostomy (generalised seizures).
The following kinds of seizures respond to surgery:
- partial seizures of temporal or extratemporal origin;
- secondary generalized seizures (attacks that begin locally and spread to both sides of the brain). For these two types of seizures, a cortectomy, or surgical removal of the area where the seizures begin, is preferred;
- unilateral, multifocal epileptic seizures associated with infantile hemiplegia, and generalized seizures, specifically those resulting in violent falls and injury, as well as, Lennox-Gastaut syndrome. These seizures may be helped by sectioning (cutting) the corpus callosum. The corpus callosum is the major pathway connecting one hemisphere of the brain to the other. Sectioning it prevents the spread of the epileptic discharge from one hemisphere to the other.