Final answer:
An epileptogenic focus on one side of the brain can cause seizures. In some cases, brain surgery may be performed to remove the area where the seizures originate.
Step-by-step explanation:
An epileptogenic focus on one side of the brain can cause seizures in the affected individual. Epilepsy is a neurological disorder characterized by recurrent seizures, which are caused by abnormal electrical activity in the brain. When there is an epileptogenic focus on one side of the brain, it means that the seizures originate in a specific area of that hemisphere.
For example, in cases of severe epilepsy, where anticonvulsant medications are not effective, brain surgery may be performed to remove the area where the seizures originate. This can help control or even eliminate the seizures. However, brain surgery is considered a last resort and is only recommended when other treatment options have failed.