There are important, long-term gains from hastening surgical interventions against epilepsy before the disease has had too negative an impact on brain functions and patients’ lives, a Swedish study found. These are some of the findings of a thesis for which more than 500 patients were studied and followed up.
“Around one third of those undergoing surgery today are children and the percentage is growing, which is encouraging. But the average time until operation for adults is still 20 years, and that’s a very long time. There’s a major lack of knowledge among the treating neurologists about which patients may benefit from epilepsy surgery,” says Anna Edelvik, researcher at Sahlgrenska Academy and senior physician on the Sahlgrenska University Hospital epilepsy team.
Around 60,000 people have epilepsy in Sweden, making it our most common chronic neurological disease. Around one out of three patients do not become seizure free from medication and it is primarily here that surgery comes in. If the epilepsy is focal, which implies that seizure onset is clearly delimited in the brain, surgery may be possible.
“We try to locate the origin of the seizures as precisely as possible, and determine the proximity to areas of vital functional importance. It’s important to be able to give good information to the patients about possible risks and benefits before making a decision to operate or not,” says Edelvik.
Her research shows that 58% of those who underwent surgery were seizure-free after five to ten years compared with 17% in the group of those who were not operated. The longer the individuals had had epilepsy, the fewer were seizure-free on the long term. The importance of acting faster is also apparent from the study concerning how many of those who underwent epilepsy surgery who were gainfully employed at long-term.
“The highest number of persons in full-time employment at long-term was found among those who worked full-time before surgery, but even if they dropped out of the labor market before surgery, about one third of the persons who were seizure-free had full-time employment after ten to 15 years. It’s important to identify the patients as early as possible before the epilepsy has had too large of an impact,” says Edelvik.
In another study, when non-surgical patients rated their health-related quality of life, it was considerably lower than among comparable individuals without epilepsy. The group who underwent surgery scored higher and was more like the age- and gender-matched reference group, but still had lower ratings for social function and mental health.
“They want to have a job and a family like everyone else, but that doesn’t happen just by becoming seizure-free. Even if the whole lifestyle situation doesn’t change, many would in any case benefit from being examined or evaluated for epilepsy surgery earlier than today,” says Edelvik.
Epilepsy surgery is a treatment option for selected patients with drug-resistant epilepsy. Patients need individual pre-surgical counselling on chances of seizure freedom and other outcomes in a long-term perspective. The aim of this thesis was to investigate long-term outcomes as to seizures, antiepileptic drugs (AEDs), employment and health-related quality of life (HRQOL) and to investigate prognostic factors for seizure and employment outcomes. All three studies were prospective, longitudinal and population-based. Study I and II were based on outcome data from the Swedish National Epilepsy Surgery Register. Study III was a controlled prospective, cross-sectional, national long-term follow-up study 14 years after epilepsy surgery evaluation where HRQOL was investigated using the 36-item Short Form Health Survey. In Study I, 62% of adults and 50% of children were seizure-free at long-term (5 or 10 years after surgery). Predictors for seizure freedom were MRI abnormalities, lower seizure frequency at baseline and shorter duration of epilepsy. At 10 years, 86% of seizure-free children and 43% of seizure-free adults had discontinued AED medication. In Study II, employment rates were mainly unchanged at group level 5, 10 and 15 years after surgery. Predictors for postoperative employment were pre-operative employment, seizure freedom and younger age. Only 57% and 47% of those who were employed full-time before surgery and became seizure-free were still in full-time employment 10 and 15 years after surgery. Out of the seizure-free patients who had been on benefits or sick leave before surgery, 30% were employed full-time at long-term follow-up. Compared to the general population fewer patients worked up to the age of 65. In Study III, HRQOL scores were compared to non-operated controls and to a matched norm population. At long-term, operated patients reached norm values on all domains except Social Functioning and Mental Health, whereas controls scored lower than norm on five of eight domains. Changes in HRQOL were small from two-year to long-term follow-up. Change in seizure status for the operated patients did not influence HRQOL results. In conclusion, long-term seizure freedom was achieved by 50-60%. Post-operative discontinuation of AEDs was common especially in seizure-free children. Many adults could continue or go back to work, and HRQOL was better at group level for operated patients than for controls. Younger age at surgery and shorter epilepsy duration were predictive of better results, indicating the importance of earlier referrals for pre-surgical evaluation