Neuroimaging in the Evaluation of Epilepsy

Naymee J. Velez-Ruiz, MD; Joshua P. Klein, MD, PhD2


Semin Neurol. 2012;32(4):361-373. 

In This Article

Abstract and Introduction


Neuroimaging has provided extraordinary insight into the pathologic substrate of epilepsy. The excellent spatial resolution and soft tissue contrast of magnetic resonance imaging (MRI) allows identification of a substantial number of pathologies including hippocampal sclerosis, malformations of cortical development, low grade tumors, and vascular abnormalities, among others. Complementary imaging modalities such as positron emission tomography, single photon emission computed tomography, and magnetoencephalography can be diagnostically helpful as well. Identification of a pathologic substrate is particularly important in patients with medically refractory epilepsy who are undergoing evaluation for surgery, and essential in determining the likelihood of seizure freedom after surgical intervention. This article reviews current and emerging neuroimaging techniques in the field of epilepsy.


One of the greatest advances in the investigation of epilepsy in the 20th century was the introduction of brain imaging. Neuroimaging has provided an extraordinary insight into the pathologic substrate of epilepsy, which is essential in determining probable course of disease, appropriate treatment, surgical candidacy, and likelihood of seizure freedom after surgical intervention. The invention and development of the electroencephalogram (EEG) predated computer tomography (CT) and magnetic resonance imaging (MRI) by decades, and as a consequence, the classification of seizures and epilepsy has been based on electroclinical features, rather than etiology or anatomic findings.[1] However, as the dynamic field of neuroimaging evolves, the paradigms for the classification of epilepsy progressively shift toward an anatomic and functional approach. Recognizing this trend, this article focuses on the neuroradiologic findings of different pathologic substrates for epilepsy.