The two surgical options used most commonly for patients with LGS are corpus callosotomy or vagus nerve stimulation (VNS) therapy. Rarely, patients with LGS may be a candidate for focal removal of the brain tissue initiating the seizures.
Corpus callosotomy has been used for several decades as a beneficial procedure to help reduce the drop attacks and the convulsive seizures in children with LGS. For the child with LGS, a complete corpus callosotomy is performed, although some surgeons do this in two stages a few months apart. The child will still need medications after the surgical procedure. Yet, many children have dramatic improvement in their drop attacks and the frequency or strength of their convulsive seizures. Before surgery these children are typically evaluated in an Epilepsy Monitoring Unit to document all their seizure types and to clarify which seizure types are expected to respond to corpus callosotomy.
The child is typically admitted to surgery the day of the corpus callosotomy. The procedure normally takes about 4-5 hours to perform. The recovery in the hospital after surgery can vary from 5 days up to one week. Some children may need more rehabilitation services (speech, physical and occupational therapies) after this procedure. However, essentially, all children should return to their level of functioning prior to surgery. The response to corpus callosotomy is noted within days after the surgery and the ongoing control of seizures is usually evident over the first 3-6 months after surgery.
Vagus nerve stimulation (VNS) therapy has also been effective for multiple seizure types associated with LGS. Again, the family should be given information on this procedure and be directed to the website (www.vnstherapy.com).
Vagus nerve stimulation seems to be most effective as a treatment for drop attacks but can also be effective for partial seizures and generalized seizures. Some children may require both corpus callosotomy and vagus nerve stimulation, performed typically at separate times. A child could have a beneficial response to one and less dramatic response to the other. Unfortunately, this cannot be predicted in advance. Additionally, some children show improvement in seizure control after each procedure.
With vagus nerve stimulation, seizures may improve over the first six months but there may be continued improvement over the next twelve months. As such, the family and their pediatric neurologist can evaluate the response that has occurred the first six months after either procedure, and make decisions about trying the other procedure at that time.
Once a decision has been made to pursue vagus nerve stimulation, the child is typically admitted for day surgery or a short hospital stay. The procedure itself typically takes 40 minutes to one hour to complete. The child may be observed overnight at the hospital or discharged home from day surgery. The child is then seen for follow up by the neurologist who makes adjustments to the vagus nerve stimulator, with increases in the dose of the device as tolerated by the child, similar to what is done with medications. The current battery life for the vagus nerve stimulator is 4-8 years, depending on the device settings. In children who respond to this treatment, a generator replacement is required before the battery runs out. This also requires a brief surgical procedure. Vagus nerve stimulation tends to be well tolerated. Some children may have a change in their voice or have a tickling sensation with coughing during stimulation, but adjustments to the device’s parameters can minimize or prevent these side effects. Some families note improvement in alertness, and behavior, in addition to seizure control with vagus nerve stimulation.