Grant: Project Grant

Epilepsy is a neurological disorder that affects 1% of Canadians. The main treatment is long term drug therapy, to which more than 30% of patients are refractory. Fortunately, surgery may be considered in cases of drug resistant epilepsy in which we can define a focal area of the brain responsible for the seizures. The goal of surgery is the resection of brain issue that generates seizures, without causing functional loss. However, there are no noninvasive techniques able to measure precisely when (on a millisecond time scale) and where (on a millimeter spatial scale) epileptic activity occurs in the brain. Some techniques are dedicated to answer "where" (good spatial resolution) in the brain, whereas others can identify "when"(good temporal resolution). Most neuroimaging techniques have been developed in order to be sensitive to different brain signals: (1) direct measurements of neuronal bioelectric activity (from scalp recordings) and (2) indirect measurement of brain activity through hemodynamic processes measuring blood flow providing oxygen to the active neurons. The objective of our work is to accurately characterize the link between these two types of measurements when studying epileptic activity, in order to quantify whether the mechanism linking neuronal activity and blood supply is preserved or impaired in this pathological condition. Having developed an ideal set-up dedicated for whole night monitoring, we propose to assess for the first time the interaction between "neurovascular coupling" processes and sleep. We expect these findings to be relevant to optimize the therapeutic approach for these candidates for epilepsy surgery.