Abstracts

Rationale: The yield of MRI in patients with newly diagnosed epilepsy has not yet been adequately assessed. In this study, we evaluated the frequency of epileptogenic lesions in patients with newly diagnosed epilepsy. Methods: In this study, 28 neurologists from across Lebanon referred their patients (at least 6 month of age) with one or more suspected unprovoked seizures to the American University of Beirut where they underwent a full evaluation. This included a detailed description of the spells, full physical and neurological examinations, sleep deprived 3 hours video-EEG study, an epilepsy protocol MRI, bone densitometry, and quality of life questionnaire. All patients diagnosed with epilepsy underwent a 1.5 T epilepsy protocol MRI including 1 mm SPGR cuts, axial and coronal FLAIR, and T2* sequences. All MRIs were reviewed by a neuroradiologist with expertise in epilepsy who was blinded to the clinical history and diagnosis. The MRIs were classified as normal, abnormal and epileptogenic, or abnormal and non-epileptogenic based on previously published criteria. Results: Of the 169 patients diagnosed with epilepsy, 134 patients already had an MRI performed. In the whole group, 57/134 (43%) had an epileptogenic lesion detected on their MRI. When stratified by syndrome type, the frequencies of epileptogenic lesions were 6%, 50%, and 56% in patients diagnosed with idiopathic generalized, symptomatic generalized and localization related epilepsy, respectively. When further stratified by age groups, the frequencies of epileptogenic lesions in adults were 0% and 70% in patients diagnosed with idiopathic generalized and localization related epilepsy, respectively. In patients less than 18 years of age, the frequencies of epileptogenic lesions were 8% and 43%, in those diagnosed with idiopathic generalized and localization related epilepsy, respectively. The difference in the frequency of epileptogenic lesions in localization related epilepsy between adults and children was statistically significant (p=0.01). However, when the MRIs of children with idiopathic partial epilepsy were excluded, there was no significant difference between the 2 groups. A variety of epileptogenic lesions was detected and will be discussed. Conclusions: A high percentage of patients with newly diagnosed epilepsy who undergo a dedicated epilepsy protocol MRI were found to have an epileptogenic lesion. This underscores the importance of obtaining a high quality MRI interpreted by an expert especially in patients with newly diagnosed localization related epilepsy.