Abstracts

Rationale: The molecular research in the field of human epilepsy is quite behind the neurodegenerative diseases such as Alzheimer’s and Parkinson’s disease. One of the main reasons being lack of availability of properly stored human tissue for research. In neurodegenerative diseases, post mortem brain donation has helped advance research, however given the young age of most epilepsy patients, postmortem brain donation is not viable as a tissue source in epilepsy research. Brain banks for epilepsy research have been developed in Europe and the United States but have not been created in Canada. The objective of this study was the creation of the first epilepsy brain bank in Canada.Methods: An epilepsy brain bank is a storage source for pieces of brain tissue from epilepsy surgery resections. The tissues are donated by the patients undergoing brain resection for the treatment of their medication refractory seizures. The tissues are slowly frozen with isopentane and stored at -80 °C. As per current standard of care in Canada, most epilepsy centers process the brain tissue obtained from temporal lobectomies or other types of resections by formaldehyde-fixation to undergo routine pathological screening. Therefore, no further research studies are performed on the specimen as the formaldehyde-fixed tissue is not suitable for most advanced research methods.Results: Our bank has created the methodology to preserve portions of tissue from 5 patients. All patients were assessed by two epileptologists at the Saskatchewan Epilepsy Program since November 2012. All of them had drug resistant epilepsy. Mean age of patients at the time of surgery was 37.2 + 13.8 years and two were males (40%). One patient has developmental delay and three had psychiatric comorbidity. Mean age at diagnosis of epilepsy was 19.8 + 17.4 years. The mean time of epilepsy evolution was 19.8+ 17.4. Mean number of medications was 2.25 + 0.5. Lesion was found with the MRI in three patients. The pathology findings were as follows: 2 cases cortical dysplasia, 2 dual pathology (MTS + cortical dysplasia) and 1 gliosis. As a part of the work up all patients had a video-EEG, MRI, memory testing and other tests depending on the case. Four patients (80%) had temporal resections and one had a fronto-temporal resection. After six months of follow up all of them were seizure free.Conclusions: The basic research on tissues saved in the bank combined with clinical knowledge may provide vital information about some of the unanswered questions in epilepsy including finding new targets for antiepileptic drugs. It also can be used to detect chronic differences in regions of the brain prone to seizures using proteomics, immunohistochemistry, and molecular biology. Also the epileptic tissue will be used to identify biomarkers of refractory epileptic activity by identifying the common abnormal pathways shared by many patients with temporal epilepsy. Finally these biomarkers will be translated into therapeutic targets, which will be tested in animal models to determine efficacy prior to clinical trials.