Towards precision surgery for focal and generalized epilepsy through network mapping

THE CONTEXT

Epilepsy is the most common chronic neurological condition in the world, affecting approximately 65 million people, including nearly 300,000 in Canada and 120,000 in Quebec. It usually manifests early in life: up to 85% of cases are diagnosed before adulthood.

In children, epilepsy leads to chronic school absenteeism caused by seizures, medication side effects, medical appointments, and stigma. This absenteeism compromises academic success and increases the risk of lasting social difficulties, socioeconomic insecurity, mental and physical health problems, and reduced life expectancy.

Medication is the most commonly used treatment to reduce epileptic seizures. Despite advances in pharmacological treatments, one-third of children remain drug-resistant, a rate that has not decreased in over 50 years.

When medication is not enough, epilepsy surgery is an option for some children. Data show that surgical procedures offer better results on their own for focal, regional, or hemispheric epilepsies. However, this approach is not without limitations: up to 50% of children who undergo surgery experience a relapse, and some do not see a significant reduction in their seizures. In addition, surgery carries cognitive and neurological risks that are sometimes unpredictable. Insufficiently precise planning can lead to overly limited intervention, causing avoidable sequelae.

Despite its potential, surgical treatment therefore remains imprecise. In addition, the effects of these procedures on the child’s quality of life and overall functioning are poorly documented. Given the high prevalence of epilepsy in children in Canada, there is an urgent need to develop a more targeted, effective surgical strategy focused on the child’s well-being.

THE PROJECT

This project aims to improve the lives of children with drug-resistant epilepsy by optimizing surgical treatment. Using advanced neuroimaging techniques, the specific brain networks to be modulated will be identified in order to better control seizures. In the long term, these advances will improve the quality of life, well-being, and school attendance of thousands of Canadian children.

The hypothesis is that the effectiveness of surgical treatment depends not only on the location of the epileptic lesion and the type of surgery, but also on the brain networks modulated by the procedure. A better understanding of these networks will make it possible to predict postoperative outcomes and guide clinical decisions toward more targeted, child-centered treatments.

THE OBJECTIVES

• Map brain networks before and after epilepsy surgery to identify changes induced by the procedure based on the location of the lesion and the type of surgery;
• Examine associations between changes in post-surgical brain networks and indicators of quality of life, well-being, school attendance, and cognitive functioning;
• Develop predictive models of post-surgical outcomes to guide clinical decisions and personalize care.

To achieve these objectives, data from 100 children with epilepsy at CHU Sainte-Justine and CIUSSS de l’Estrie – CHUS will be analyzed. Each child will undergo pre- and post-operative MRI scans, allowing for analysis of changes in brain networks induced by the procedure. In addition, questionnaires completed by caregivers before surgery and then 6 and 12 months after the procedure will be taken into account.

POTENTIAL IMPACT ON CHILDREN’S HEALTH

This project proposes an innovative approach to personalizing surgical interventions in pediatric epilepsy by integrating an understanding of brain networks modulated by surgery. These advances will improve the health of thousands of Canadian children by:

1) optimizing surgical plans based on each child’s neurofunctional profile;

2) predicting postoperative clinical, cognitive, and psychosocial trajectories to better guide clinical decisions;

3) reducing hospitalizations, complications, and long-term impacts on development. This approach will promote better academic, social, and family integration.