Imaging and Treatment Decisions in Seizures and Epilepsy

Abstract

It has been clearly shown that magnetic resonance imaging (MRI) is the preferred modality of structural imaging for both new onset seizures and established epilepsy. MRI imaging in epilepsy requires a dedicated MRI protocol in order to detect subtle epileptogenic lesions such as focal cortical dysplasia or hippocampal sclerosis. Thin-slice thickness and orientation in the longitudinal axis of the hippocampus and perpendicular to it are the main characteristics of dedicated epilepsy MRI. An expert experienced in epilepsy and imaging should interpret epilepsy MRI. The new generation of 3 Tesla (T) MRIs is more sensitive, particularly for focal cortical dysplasia. Epilepsy-dedicated MRI is indicated particularly at the time of first seizure or new onset epilepsy, and when epilepsy becomes drug refractory. Results of a lesional MRI will assist in classifying the epilepsy syndrome and may well have an influence on treatment planning. Particularly in focal drug refractory epilepsies, a lesional MRI result may indicate a good hypothesis for presurgical assessment. If structural MRI is non-lesional, MRI post-processing may help to identify subtle epileptogenic lesions. CT scanning should only be performed in acute settings if MRI is not available or if the patient is too unwell for MRI scanning.