Surgery is usually a last option for treatment. While surgery may be considered by people with intractable epilepsy (seizures that do not respond to drug treatment), it is not an option for everyone.
Surgery is considered only when seizures are frequent and when drugs or other treatment options have failed. Seizure surgery is never undertaken lightly. It is less dangerous than people think. Recovery is often quite rapid.
Parents may consider surgery as an option for children who have uncontrolled partial seizures, particularly if the child is experiencing serious drug side effects. A doctor or neurologist must refer their clients to a surgeon.
This procedure has undergone extensive testing. It is a renowned and effective treatment for seizure control where medication is inadequate. For 80 per cent of good candidates, this surgery successfully eliminates seizures altogether.
Who is a candidate?Expand Who is a candidate? Section
People are considered “good candidates” for this procedure if they have focal seizures that originate in a part of the brain that can undergo a lobectomy without significant impairment. Resective surgery removes the section of the brain where seizures originate.
For parents considering surgery for their child, the child must have:
- frequent, drug-resistant seizures that disrupt life
- seizures that always originate in the same part of the brain
- seizures that occur in a part of the brain, which can be removed
Not all children with drug-resistant seizures are candidates for seizure surgery. Children with seizures arising from many sites (multifocal epilepsy) or many primary generalized seizures (no clear focus of onset) are usually not helped by surgery.
What investigations are required?Expand What investigations are required? Section
People who have tried two different medications without successfully gaining control over their seizures may ask their physician for a referral to an epilepsy specialist for further evaluation. The epilepsy specialist may admit the patient into the epilepsy unit in a hospital for tests that determine whether brain surgery is an option. This may include:
- Electroencephalogram (EEG)
- special 24-hour EEG monitoring in an Epilepsy Monitoring Unit (EMU)
- Magnetoencephalography (MEG) or Magnetic Source Imaging (MSI)
- Neuropsychological Tests
- Single Photon Emission Computed Tomography (SPECT), or
- Wada Test
Families considering surgery must be motivated to undergo extensive testing to localize the seizure focus and to determine whether it can be safely removed. It is sometimes necessary to activate electrical activity in the seizure focus by withdrawing anticonvulsants, by depriving the patient of sleep, or by administrating drugs to precipitate seizure activity.
What types of surgery are done?Expand What types of surgery are done? Section
There are many different types of surgery. The type of surgery a person receives depends on the type of seizure and where the seizures originate in the brain. Surgery cannot be performed when the source of the seizure activity cannot be pinpointed or when the seizures originate from an area of the brain involved in essential functions (i.e. language, memory). Surgery must be considered with great caution because of the potential risks involved.
1. Removal of a focus is by far the most common procedure. Children who undergo it have partial seizures or, most commonly, complex partial seizures. Sometimes a whole lobe of the brain, such as the temporal lobe is removed. The procedure is then called lobectomy.
2. Callosotomy is done in patients with some types of intractable generalized seizures, particularly atonic (drop) syndrome or Lennox-Gastaut syndrome. Callosotomy interrupts the connections from one half of the brain to the other, so seizures no longer spread from the epileptic side to the normal half of the brain. Callosotomy does not cure children of epilepsy, but it can help decrease the frequency and severity of the seizures.
3. Hemispherectomy is rare. It is done when one half of the forebrain (a hemisphere) is totally malfunctional, usually because of severe developmental abnormalities. The affected hemisphere retains no normal function, but produces drug-resistant seizures. Surgeons remove the hemisphere to improve seizure control.
Anesthesia for SurgeryExpand Anesthesia for Surgery Section
Most surgical candidates are children with a single seizure focus. These operations can be done under general anesthesia.
When seizures arise near areas of the brain involving important functions such as speech, motor control or sensations, surgery in older children is begun under local anesthesia (or neuroleptanalgesia) with the patient awake and fully cooperative. The patient is put to sleep before the actual removal is done.
Risks vs. BenefitsExpand Risks vs. Benefits Section
As with any operation, there are risks to seizure surgery. These risks, which relate to the area being removed, include producing disturbances in motor strength, sensation, vision or speech. There are also rare cases of surgical mortality. Fortunately, with continuing refinement in neurosurgical techniques, the chances of long-lasting complications are only about 2 per cent.
The benefits of surgery are the child may become seizure free, or at least have milder seizures that can be controlled by anticonvulsant medication.
The decision to have your child undergo surgery is a difficult one. It will require a great deal of consideration, discussion with many professionals and extensive testing of your child.