MRI in the evaluation of epilepsy in adults – a pictorial review of common epileptogenic pathologies
Epilepsy affects approximately 1% of the UK population, with drug-resistant cases posing significant therapeutic challenges. MRI plays a pivotal role in diagnosing and managing epilepsy, particularly for presurgical evaluation, as up to 80% of drug-resistant patients may have surgically treatable lesions. The International League Against Epilepsy recommends the HARNESS-MRI protocol, incorporating high resolution 3D T1, FLAIR and coronal T2 sequences, ideally on 3.0T scanners, to maximise lesion detection.
Common epileptogenic pathologies include mesial temporal sclerosis, the leading cause of focal epilepsy, characterised by hippocampal atrophy and T2/FLAIR hyperintensity. Malformations of cortical development such as periventricular nodular heterotopia, focal cortical dysplasia (notably type IIB with the transmantle sign), polymicrogyria and lissencephaly are frequent in adults. Other causes include traumatic brain injury, post-stroke epilepsy and cerebral amyloid angiopathy, all associated with structural changes detectable on MRI, often using susceptibility-weighted imaging for haemorrhagic lesions.
Epileptogenic tumours, particularly long-term epilepsy-associated tumours like gangliogliomas and dysembryoplastic neuroepithelial tumours, exhibit distinctive imaging features and are amenable to surgical resection, often resulting in seizure control. Vascular abnormalities such as cavernomas and arteriovenous malformations, as well as encephaloceles and neurocutaneous syndromes, also contribute to epilepsy.
In conclusion, dedicated MRI protocols interpreted by experienced neuroradiologists are essential for identifying subtle but surgically relevant lesions, improving patient selection for surgery and enhancing long-term seizure outcomes.
To download and read this article as a pdf please sign up to our newsletter.
The content on this page is provided by the individuals concerned and does not represent the views or opinions of RAD Magazine.
