“In a recent survey in Canada, of the estimated 20,000 patients who might benefit from epilepsy surgery, only 350 had been treated with surgery,” said Dr. Mary Connolly, Head of Pediatric Neurology and Director of the Epilepsy Surgery Program at BC Children’s Hospital in Vancouver, British Columbia.
“Epilepsy surgery is an under-utilized treatment not only in Canada, but all over the world. Many children and adolescents with epilepsy spend years on medications which are unsuccessful in controlling their seizures, only to end up having an operation as adults,” said Connolly.
Epilepsy affects 0.5 – 1 per cent of the population. Anti-epileptic drugs remain the first line of treatment and for about two-thirds of patients, seizures are controlled with medication. Many children outgrow the tendency to have epileptic seizures. For the remaining one-third, epilepsy surgery, the ketogenic diet and vagus nerve stimulation are treatment options.
At BC Children’s Hospital, more than 200 children have undergone surgical treatment since the Provincial Epilepsy Surgery Program was established in the early 1990s. “The youngest patients were aged three months, at the time of surgery,” said Dr. Paul Steinbok, Head of Pediatric Neurosurgery at BC Children’s Hospital. “Left untreated, that patient’s seizures would have prevented their brain from developing properly.”
The Epilepsy Surgery team at Children’s is referred patients from Manitoba, Saskatchewan and Nunavut, as well as throughout B.C.,” said Steinbok. “So the perception that epilepsy surgery is a treatment of last resort is finally starting to change. But too many health-care providers are simply unaware of how successful today’s surgical procedures are.”
The most common epilepsy surgery involves removal of that area of the brain identified as the source of, or trigger of, epileptic seizures.
“As with any procedure, you carefully assess each individual patient,” said Connolly. “Our assessment team includes neurologists, neurosurgeons, radiologists, nurses, EEG technologists, radiology and nuclear medicine technologists and a neuropsychologist.”
Potential candidates for epilepsy surgery come to Children’s for video-EEG monitoring over a period of days to capture and record typical seizures. This allows the neurologist to assess where the seizures begin within the brain.
MRI imaging provides a detailed look at the patient’s brain structure to help identify the epileptic focus. Selected patients undergo SPECT and PET scanning which enable one to look at brain function if the MRI fails to show a structural lesion.
A neuropsychologist with experience in epilepsy performs a detailed assessment of functions such as language, memory, attention and other tasks.
A family-centered care approach helps the parents understand what the procedure looks like and its associated risks. “We want families and children to be as well informed as possible before making their decision,” said Steinbok.
“In some patients, we put the part of the brain targeted for removal to sleep and then assess the effects,” said Connolly. “In some patients, other parts of the brain may often take the function of an area which is removed.”
This phenomenon is referred to as “brain plasticity”. The classical example is a child who experiences injury or even surgery to the left side of the brain, which is usually responsible for language, early in life. In these patients, language ability transfers to the right side of the brain.
Patients just want to be like their friends. Thirteen-year-old Colin Fetterly of Victoria, who was nine when he was diagnosed with temporal lobe epilepsy, experienced seizures every second day; sometimes 15 seizures in a single day.
The cause was a scar on his temporal lobe, the result of a high fever and convulsions when he was just seven months old. Because the brain was already damaged, Dr. Steinbok could be confident that removing that part of his temporal lobe would not necessarily cause any harm.
“I wanted the surgery,” said Fetterly. “I thought it would be a great idea because I wouldn’t be made fun of or have to take meds.”
“My reaction to the idea of brain surgery was no wayÊI don’t think so,” said Colin’s mother Laura. “After surgery I said miracles do happen, thanks to Children’s Hospital.”
Since Colin had his surgery in July last year, he has not experienced a single seizure, and there’s an 80 per cent chance he will never experience another one.
There are risks associated with the removal of a specific area of the brain, such as worsening of memory in patients who have temporal lobe surgery. However, a study by Dr. Sare Akdag, BC Children’s Neuropsychology Service (while an intern at Rush Medical Center in Chicago, Illinois) demonstrated that in many patients with temporal lobe epilepsy surgery, memory was the same or better following surgery, possibly due to fewer epileptic seizures.
Doctors at BC Children’s Hospital strive to minimize the use of transfusions in all surgical procedures, and typically do not require one with most epilepsy surgeries. If it is likely that the patient will require a transfusion, those patients are encouraged to donate their own blood in advance of the procedure.
“The equipment we use is the same as that found at most other pediatric hospitals in Canada,” said Steinbok. “What’s different is that we allow hemoglobin levels to drop lower than what was once thought acceptable, so if you are willing to take a little longer to perform the surgery to be meticulous about saving every drop of blood, there’s no reason other hospitals can’t achieve the same results.”
“I would like to see more physicians using epilepsy surgery to help their patients,” said Connolly. “In any patient with seizures which do not respond to anti-epileptic medications, the question should always be asked might epilepsy surgery be a treatment option for this patient? We can give those patients what they’ve always wanted; a normal, seizure-free life.”