LAUSR

Nearly 140,000 Canadians live with epilepsy, and many suffer social stigma and economic disadvantage as a result [1]. For patients with medically refractory focal epilepsy, surgical resection of epileptogenic tissue improves seizure control and offers the possibility of seizure freedom [2]. The presurgical workup of these patients involves a triangulation of seizure semiology, electroencephalographic data and neuroimaging data [3]. Magnetic resonance imaging (MRI) plays a critical role in the identification, localization, and characterization of epileptogenic lesions [4]. Patients with chronic focal epilepsy and an epileptogenic lesion identified by MRI have significantly better surgical outcomes, compared with patients who are considered MRI-negative [5,6]. Early use of MRI may also benefit many patients with a first seizure or new-onset epilepsy, as the information gained from MRI can aid in counseling, help with the decision to start antiepileptic drug therapy, and expedite referral for epilepsy surgery when appropriate [7]. MRI has been reported to detect abnormalities in 74% of patients suffering from medically refractory focal epilepsy [8]. The detection rate in this population may be as high as 91% with the use of dedicated epilepsy imaging protocols that are interpreted by experienced neuroradiologists who work at epilepsy referral centres and have access to clinical information about the seizure semiology [9]. One would expect the detection rate to be lower in the relatively undifferentiated group of patients presenting with a first