What is epilepsy surgery?
Seizure is a single episode of uncontrolled discharge of one group of brain cells (neurons) whereas epilepsy is a neurological entity characterized by multiple unprovoked seizures.
Up to 10% of all people suffer from single seizure during their life time; However only 1% of people are diagnosed with epilepsy.
There are many causes of epilepsy in adults and children including congenital syndromes, cortical dysplasias, hypoxic-ischemic brain injury, cerebral palsy, brain tumors, hamartomas, hippocampal sclerosis, AVMs, cavernomas, infections, metabolic and hormonal imbalance, drugs, etc. Primary treatment is medication(s) in idiopathic epilepsy and almost 1 out of 5 epileptic patients (20%) eventually do not get enough benefit from anti-epileptic medications (pharmaco-resistant epilepsy) and these patients are considered as candidates of epilepsy surgery.
Major Types of Epilepsy Surgery
Major types of epilepsy surgery is as follows,
Temporal lobe epilepsy is the epilepsy type which originates from the most inner surface (mesial temporal lobe) and results in complex partal seizures. In this type of epilepsy, hippocampal sclerosis(atrophy (degeneration of hippocampus) is a common finding in brain MR. Micro-neurosurgical removal of degenerated hippocampus and adjacent amygdala effectively eliminates this type of epilepsy. Selective amygdala-hippocampectomy surgery is a technically elegant surgery which spares the neocortex and targets only the removal of the epilepsy source (amygdala and hippocampus) with a high success rate (95-97%).
Vagal Nerve Stimulation (VNS)
Vagal nerve stimulation surgery can be defined as the wrapping of an electrode around the vagus nerve in the neck and connecting it to a battery so as to transmit the electrical impulses onto the nerve in a retrograde fashion up to the brain and suppressing the epilepsy producing structures (epileptogenic areas) in the brain. VNS surgery is reserved for pharmaco-resistant epilepsies arising from more than 1 epileptic foci (multi-focal epilepsy). The success rate for decreasing the frequency of epilepsy is around 50-70%.