Epilepsy surgery for children – from a neurosurgeon’s perspective
Epilepsy is a neurological condition characterised by recurrent seizures, or convulsions that occur when there is abnormal electrical activity in the brain. Epilepsy South Africa estimates the condition affects one out of every 100 people in South Africa, with 75% of those experiencing their first seizure before the age of 20.
There are numerous treatments for the condition, including medication, dietary intervention and surgery.
Epilepsy surgery, essentially a neurosurgical procedure in which the part of the brain causing the epilepsy is either removed or disconnected, is divided into three main categories:
- Anatomical resection procedures (removal of the frontal lobe or temporal lobe)
- Disconnection procedures (disconnecting the epileptiform cortex from the rest of the brain by sectioning white matter tracts)
- Neuromodulation (deep brain stimulation for epilepsy)
Dr Roger Melvill, the neurosurgeon at Mediclinic Constantiaberg Epilepsy Unit, explains that patients who have repeated epileptic events that are not controlled by medication, or who have their epilepsy medically controlled at a massive cost to their general wellbeing and quality of life, are potential candidates for surgery.
“Occasionally we have very young children who present with severe epilepsy as babies,” he explains. “In these cases, there may be a maldevelopment of the brain causing the epilepsy to emerge so early in life. In some rare circumstances, the abnormality in the brain is confined to only one half of the brain. If the epilepsy is severe, uncontrolled, and confined to one hemisphere, it’s feasible to disconnect that half of the brain from the rest of the brain, even in young children.”
The operation is known as a hemispherotomy – hemisphere being the two halves of the brain, and –otomy meaning cut. The procedure does not involve removal of the abnormal brain tissue, but rather separating the abnormal half of the brain from the normal opposite side. The operation is technically very complex and often takes up to ten hours.
“Sometimes the frequency and severity of the epilepsy are such that the child’s life is at risk because of the condition. That’s why sometimes one is forced to operate on very young patients,” Dr Melvill says.
“There are many experts involved in a neurosurgical operation,” he adds. “With very young children, the anaesthetist has the onerous task of keeping that tiny baby in good health throughout the operation. In turn, the paediatrician must care for the patient during the difficult post-operative period. It is very much a team effort.”
A team approach
The teamwork behind neurosurgery begins at the point of the initial decision to operate.
“As the neurosurgeon, I don’t get to make the decision on my own as to whether the operation should be performed,” Dr Melvill says. “The epileptologist, an expert neurologist who devotes his life attending to people who suffer from epilepsy, is the medical specialist who first makes the call, in consultation with the neurosurgeon. It is then that the surgical team, the surgeon, the anaesthetist and the paediatrician prepare the patient for surgery and the post-operative phase. It’s closely coordinated by the entire team.”
Technology also plays a crucial role in this surgery. Before the procedure can take place, the patient is connected 24/7 to an electroencephalogram (EEG) and a continuous video monitor, to detect the precise location of the abnormal electrical activity in the brain causing the seizures.
During the surgery, an MRI image of the brain is presented on a computer screen. This is linked to a camera system that allows the surgeon to have a real-time view of the brain anatomy. This neuro-navigation, rather like a GPS system, is an important technical advance for this delicate operation.
“Once the surgery is done, the young patient recovers in ICU, where the teamwork continues,” Dr Melvill adds. “As well as ongoing care by the paediatrician, the patient is in the hands of nursing staff who are nothing short of phenomenal. The specialists have deep respect for those nursing staff who have devoted their lives to caring for our patients in the unit.”
“Neurosurgery comprises many parts, each of which is handled by experts in their field. As a neurosurgeon, I’m simply one of the cogs that make up an intricate wheel that enables the process to happen,” Dr Melvill concludes.