The underlying mechanism of epileptic seizures is excessive and abnormal neuronal activity in the cortex of the brain. The reason this occurs in most cases of epilepsy is unknown. Some cases occur as the result of brain injury, stroke, brain tumors, infections of the brain, or birth defects.
Seizures are controllable with medication in about 70% of cases. In some people, seizures do not respond to medication, or appropriate surgery. Use of medicinal cannabis to treat epilepsy has been studied for a number of years.