ESR Essentials: Image evaluation of patients with seizures and epilepsy-practice recommendations by the European Society of Neuroradiology.

Abstract

Epilepsy, a neurological disorder characterised by recurrent seizures, poses significant challenges in diagnosis, treatment, and management. Understanding the underlying causes and identifying precise anatomical locations of epileptogenic foci are critical for effective management strategies, particularly in drug-resistant patients. Neuroimaging techniques, particularly magnetic resonance (MR), play a pivotal role in the evaluation of epilepsy patients, offering insights into structural abnormalities, epileptogenic lesions, and functional alterations within the brain. Diverse clinical scenarios that warrant neuroimaging in epilepsy patients, ranging from first-onset seizures to drug-resistant epilepsy, will be presented, elucidating the considerations and recommendations for imaging modalities. The dedicated MR protocol for epilepsy patients will be discussed, justifying the rationale behind sequence selection and optimisation strategies and providing clues about how to read these magnetic resonance imaging (MRI) exams. Finally, MR findings associated with common epileptogenic lesions, such as hippocampal sclerosis, focal cortical dysplasia, and long-term epilepsy-associated tumours, will be described. This article reviews essential concepts, including definitions, classification, imaging indications, protocols, and neuroradiological findings, aiming to understand how neuroimaging contributes to diagnosing and managing epilepsy comprehensively. KEY POINTS: MR should be performed in adults and children with a recent diagnosis of epilepsy of unknown aetiology, a first seizure, and a negative CT. Performing a dedicated MR protocol in focal epilepsy is essential for increasing the detection of potentially epileptogenic lesions. For presurgical evaluations, MR abnormalities should correlate with the electric pattern, semiology data, or other neuroimaging examination to be considered the epileptogenic lesion.