New study reveals insight into epilepsy surgery success and failure

Surgeons in an operating theatre. Ref: www.dreamstime.com

A new US study has shed new light on the reasons why epilepsy surgery in children succeeds in some patients but fails in others.

Carried out by the University of California, San Francisco, the research aimed to determine why some patients continue to experience seizures even after undergoing resective surgery – a process that involves removing the parts of the brain responsible for causing epileptic symptoms.

Resection is recognised as a safe and effective option for children with pharmacoresistant focal epilepsy, though it is not always successful. Most studies of paediatric epilepsy surgery focus on predictors of postoperative seizure outcome, but these factors are often not modifiable, meaning the reasons for treatment failure may remain unclear.

The new study – published in the Journal of Neurosurgery: Pediatrics – involved a retrospective review of 110 children and adolescents who received focal resective surgery for pharmacoresistant epilepsy, ranging in age from six months to 19 years at the time of surgery.

A total of 115 resections were conducted among this group. After a mean 3.1-year follow-up period, 76 per cent of patients were found to be free of disabling seizures.

It was shown that positive outcomes predicted by the use of temporal lobe surgery compared with extratemporal resection, tumour or mesial temporal sclerosis compared with cortical dysplasia or other pathologies, and by a lower preoperative seizure frequency.

Meanwhile, factors associated with persistent seizures included residual epileptogenic tissue adjacent to the resection cavity, an additional epileptogenic zone distant from the resection cavity, and the presence of a hemispheric epilepsy syndrome.

The researchers concluded: “While seizure outcomes in paediatric epilepsy surgery may be improved by the use of high-resolution neuroimaging and invasive electrographic studies, a more aggressive resection should be considered in certain patients, including hemispherectomy if a hemispheric epilepsy syndrome is suspected.

“Family counselling regarding treatment expectations is critical, and reoperation may be warranted in select cases.”

Epilepsy surgery is one of a number of options available to people whose conditions cannot be brought under control by the use of antiepileptic drugs – a situation that applies to around 30 per cent of those who receive these medications.

Posted by Anne Brown