Neuroimaging of epilepsy: a review of MRI findings in uncommon etiologies and atypical presentations of seizures

Imaging patients with seizures presents a challenge to both clinician and radiologist, especially when symptoms or EEG features are atypical, not conforming to established epilepsy syndromes or EEG patterns. Appropriate, directed use of MRI enhances the detection of underlying epileptogenic foci and can evaluate both common and unusual etiologies. This review examines imaging evaluation of epilepsies due to uncommon presentations of common conditions, unusual conditions and atypical seizure presentations. Understanding these uncommon presentations of seizures ensures optimal clinical management and can guide appropriate intervention. Advances in newer imaging methods including diffusion tensor imaging, functional connectivity MRI, magnetic source imaging and magnetic resonance spectroscopic imaging can further increase sensitivity to detect subtle structural abnormalities causing epilepsy and can also be used to plan more successful epilepsy surgery.