The largest part of the brain, the cerebrum, is divided into two hemispheres. Each hemisphere is divided into four lobes: the frontal lobe, the parietal lobe, the occipital lobe and the temporal lobe. The temporal lobes are located on either side of the head, just above the ears. Temporal lobes are involved in hearing, language, and memory.
Temporal lobe epilepsy includes a variety of seizure types and syndromes that involve portions of the temporal lobe. It is the most common type of epilepsy evaluated for surgery, and is more common in adults than children. Surgical removal of a portion of the temporal lobe used to be called temporal lobectomy, but now the preferred term is "temporal resection."
Indications
Temporal resection is considered when:
- seizures have persisted, despite trying two or three medications alone or in combination
- pre-surgical evaluation points to a problem in the temporal lobe of the brain and has identified the epileptogenic region in the temporal lobe
- it is possible to remove the epileptogenic area without affecting the critical functional areas of the brain.
Before surgery
A complete and comprehensive pre-surgical evaluation is essential to locate the exact section or sections to be removed.
The surgeon and the team will explain the surgery to you and discuss all related issues. They will instruct you on any specific steps to take prior to the operation.
They will also discuss post-operative symptoms, any intensive care and rehabilitation that will be required, and possible ongoing deficits and care.
Surgery
The operation will take about six hours and will require a general anaesthetic.
A portion of your child's head will be shaved. Part of the scalp and bone will be removed and the dura membrane will be peeled back to expose the area of the temporal lobe to be removed.
During the operation, intraoperative intracranial EEG monitoring may be done to help the surgeon finely locate and remove or disconnect only those parts of the brain that cause the seizures. Adults and teens may be kept awake during part of the operation, using local anaesthesia to eliminate pain, to perform tasks while the functionality of certain parts of the brain are mapped out. This is done to avoid removing functionally vital parts of the brain. This is very rarely done in children.
After the operation, the bone will be replaced and the scalp will be sutured closed. Your child will spend a few hours in the recovery room until they come out of anaesthesia and one or two days in the intensive care unit, followed by about a week at the hospital.
Possible side effects after surgery
Side effects of the surgery depend on the specific areas of the temporal lobe that are removed. Temporary side effects of this surgery, which should disappear on their own in a few days, may include scalp numbness, nausea, fatigue, depression, headaches, difficulties with memory, speech, or vision, and auras (feelings that signal the start of a seizure). Rarely, some of these effects may persist. The surgeon and neurologist can talk with you about the side effects they expect for your child.
Your child may benefit from doing exercise therapy to improve any physical weakness or loss of co-ordination they may have. In the hospital, physical and occupational therapists will help your child and may show you some exercises. They may also need speech therapy if their speech has been affected.
Once your child is at home, they may need to continue using the services of a physical or occupational therapist in the community. Alternatively, they may be given some exercises to do on their own. The treatment team will discuss this with you and may be able to help you find a therapist.
The hair should grow back and most children are able to return to normal activities and school two or three months after surgery.
Anti-epileptic drugs should be continued after the surgery. As always, any change in dosage should be made with the advice and monitoring of your child's doctor. Sometimes the drugs can be stopped after a few seizure-free years.
If seizures should occur after the operation, further careful evaluation (using tests and scans) and possible re-surgery may be required. Alternatively, other treatments may be tried.
What can you expect from the surgery?
Every child is different. Depending on the nature of your child's seizures and the location of the epileptogenic region, surgery may result in complete seizure control or "partial" seizure control with less need for medication. There may also be some chance that the surgery will not improve things. Talk to your child's doctor about what you and your child can realistically expect as a result of the surgery.
Complications and risks
Every surgical procedure has related risks, including infection, bleeding, cerebral edema, and allergy to or complications from anaesthetic. Your child's doctor will discuss the risks of this procedure with you in detail.