The majority of children with epilepsy respond well to medications. However, 20% to 30% of patients with epilepsy have seizures that are difficult to control even with two or more appropriately chosen antiseizure medications. When seizures cannot be controlled by two or three medications, this is referred as refractory epilepsy.

High seizure burden in children with refractory epilepsy increases the number and intensity of hospitalizations and the risk of developmental and medical complications, as well as the incidence of sudden unexplained death in epilepsy (SUDEP).

For children with refractory epilepsy, Norton Children’s Neuroscience Institute, affiliated with the UofL School of Medicine, offers a full range of management options for medically refractory epilepsy. Ketogenic diets and palliative therapies, such as vagal nerve stimulation and corpus callostomy, are routinely implemented in carefully selected patients with refractory epilepsy. Beyond dietary and palliative care is a state-of-the-art surgical epilepsy program that offers advanced imaging analysis, minimally invasive procedures such as laser ablation, and new therapies like responsive neurostimulation (RNS).

The basis for choosing the appropriate nonpharmacological intervention in children with refractory epilepsy is a thorough and careful evaluation. At Norton Children’s Neuroscience Institute, children with refractory epilepsy undergo individualized evaluations using several diagnostic modalities (e.g., scalp EEG, MRI, MEG, fMRI, PET and SPECT studies), genetic testing, neuropsychological assessment and additional postprocessing of imaging data.

The goals of surgical epilepsy evaluation are to identify the location of seizure onset and clearly map crucial areas of brain function, such as language and motor skills. Often, children may undergo invasive EEG evaluation using either subdural electrode grids or, more recently, multiple depth electrodes (also known as stereo EEG), which are placed in precise spots in the brain using tiny cranial access holes to pinpoint the location of seizure onset.

We have a dedicated multidisciplinary team consisting of pediatric epileptologists, neurosurgeons, neuropsychologists, neuroradiologists and biomedical specialists. We hold a weekly conference to discuss our patients in order to best plan further diagnostic evaluations and therapeutic interventions. A deeply collaborative process helps our patients receive the best plan for each of them.

Available surgical options

Refractory epilepsy in children can be caused by cortical dysplasia, brain malformations, head injury, brain tumor, stroke, genetic disorder or brain infection. Sometimes the cause is unknown. Norton Children’s Neuroscience Institute offers these children and their families options based on the latest research and using advanced techniques and technology.

Resective and disconnective epilepsy surgery

Many times, children with epilepsy have a seizure focus that can be removed or disconnected safely from the rest of the brain. After careful consideration of where the focus is and what function might be lost by excluding this part of the brain, a craniotomy and resection/disconnection might be offered. Sometimes the focus is small; sometimes it will require disconnecting several lobes. Because of frequent neurological deficits that occur with a surgery like this, we conduct a very careful informed consent with the family to help them make the best decision about their child’s treatment.

Visualase

Based on an extensive diagnostic process to pinpoint the source of the seizures, Visualase MRI-guided ablation is minimally invasive laser surgery to destroy the tissue causing seizures and preserve healthy surrounding tissue. During a 90-minute procedure, a 1.65-millimeter laser catheter is inserted through a small burr hole in the skull and positioned using the MRI before the laser pulse is fired. Laser ablation has a good success rate at eliminating seizures. The complication rate is low, and patients often are discharged the next day.

Vagal nerve stimulation therapy

Vagal nerve stimulation (VNS) therapy is outpatient surgery commonly offered to children if no definite seizure focus is identified or seizure focus cannot be resected because of its location. For example, it may overlap with an eloquent region of the brain. VNS therapy sends small electric pulses to the brain throughout the day through the vagus nerve. A VNS therapy generator is implanted in the left chest using a small incision and connected to the vagus nerve in the neck. VNS therapy has been proven to result in a 40% to 50% reduction in seizure burden, decreasing the number and duration of seizures and reducing the number of antiseizure medications. It also lessens the risk of SUDEP.

Corpus callostomy

In children with multifocal epilepsy, interrupting or limiting seizure spread between the hemispheres by cutting the corpus callosum has been shown to be beneficial for patients who experience drop seizures. Studies have shown this procedure results in consistent, significant improvement in reducing the number of falls and thereby preventing injuries. It’s important to note the procedure does not stop seizures but limits their spread. The inpatient surgery can either be performed conventionally or using a laser, and can be partial or complete. Children undergoing a corpus callostomy require one to two days in intensive care and one to three days in the neurology/neurosurgery inpatient unit. Many patients also will need five to 10 days of inpatient rehabilitation after the procedure.

Functional hemispherectomy

Reserved for children with severe seizures, a functional hemispherectomy is a surgical procedure in which one half of the brain is disconnected from the rest to prevent the spread of electrical impulses. In carefully selected cases, hemispherectomy offers a high success rate of stopping seizures. The procedure will result in permanent decreased function in the opposite arm and leg, along with half or peripheral vision. A hemispherectomy is a six- to seven-hour surgical procedure, and children spend one to two days under observation in intensive care before being transferred to the medical floor. Once a child is medically stable, they undergo rehabilitation.