There are times when antiepileptic medications (AED) do not suppress seizures in children. If a child is treated with 2 or more appropriate AEDs with no improvement, he or she is deemed pharmacoresistant (resistant to medication.) In such cases, it should be investigated if your child is a surgical candidate since this offers the best chance of significantly reducing or stopping seizures.
Our Comprehensive Epilepsy Center offers several subspecialty clinics, including the surgical evaluation clinic. This specialized clinic is staffed by the epileptologist, neurosurgeon, nurse navigator, and sometimes, the physiatrist (Physical Medicine and Rehab physician). This team includes you and your child in a detailed discussion of the care plan. They discuss the results of all tests and the potential surgical treatment options available for your child.
We encourage your questions and input. As your child is able to understand, the physicians will speak to him or her. They will discuss in simple terms exactly what is going to be done. We find outcomes are better and recovery is easier when the parents and child understands the treatment, is able to have all questions answered, and mutually decides on the surgical option.
Palliative Surgery Options
The following options may provide comfort from the symptoms of seizures.
A corpus callosotomy is a procedure that cuts the membrane that divides the right and left cerebral hemispheres. This interferes with the spread of the seizure from one side of the brain to the other. It does not stop a seizure from starting, but can make it less intense and shorter. Its success in improving the seizures is over 50%.
Some children have sudden generalized seizures that produce falls and injuries from “drop attacks”. Others may have partial seizures arising from multiple independent seizure sites in the brain with very rapid spread to the entire brain such as Lennox-Gastaut syndrome. The corpus callosotomy tend to improve markedly these types of seizures.
Complications of corpus callosotomy are greater than with frontal or temporal lobe surgery. Behavioral, language, and other problems may temporarily affect function and the quality of life, but serious problems are uncommon. The potential risks of callosotomy must be weighed against its possible benefits. Benefits include a reduction in the frequency of seizures that cause injury and other problems. Patients may need inpatient rehabilitation for a short period to recover some of their speech and motor abilities temporarily affected after surgery. Since the corpus callosum is buried deep between the frontal lobes, the middle portions of these lobes must be separated, which poses some risk. Surgical advances may help to minimize this risk.
Seizure frequency is reduced by an average of 70% to 80% after partial callosotomy and 80% to 90% after complete callosotomy. Partial seizures are often unchanged, but they may be improved or worsened. In many cases, especially after partial callosotomy, seizures may persist, but are less frequent.
Vagal Nerve Stimulator (VNS)
The Vagal Nerve Stimulator (VNS) is a disk about 2 inches across (similar to a pacemaker). It is placed under the skin in the upper part of the chest while the patient is under general anesthesia. The surgeon wraps its lead wires around the vagus nerve. The vagus nerve begins in the brainstem (the lower part of the brain) and travels through a large portion of the body (neck, chest, and part of the abdomen).
After the VNS is implanted, the pediatric neurologist will program it to deliver a series of electrical stimulations to the vagus nerve at various strengths and frequencies. It works by repetitively stimulating the vagus nerve for a period of time and then pausing. The VNS device can be used for both partial and generalized onset seizures.
A magnet, supplied by the device maker, can be used to activate a stronger electrical stimulation when a patient is observed to be experiencing a seizure. This can be helpful in stopping the seizure.