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Drug-resistant focal epilepsy undergoing presurgical assessment — MSRA MCQ

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HardMRIDrug-resistant focal epilepsy undergoing presurgical assessmentMSRA

A 37-year-old man is reviewed in a specialist epilepsy clinic. He has had focal impaired-awareness seizures since age 31, typically beginning with a rising epigastric sensation and behavioural arrest, followed by oral automatisms and 2 minutes of postictal dysphasia. A routine brain MRI performed soon after diagnosis was reported as normal. Despite adherent, adequately dosed trials of lamotrigine and carbamazepine monotherapy, he continues to have 2 to 3 seizures monthly. Video-EEG telemetry now demonstrates left temporal seizure onset. He is being referred to a tertiary epilepsy service to consider resective surgery. He has no contraindication to MRI. What is the most appropriate neuroimaging plan?

Educational content. Not a substitute for clinical judgement or local policy.

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Correct answer: C — Arrange an additional MRI using a regionally agreed epilepsy protocol as part of tertiary surgical assessment

Explanation lettering: C = shown as B · D = shown as C · E = shown as D · B = shown as E

This man has drug-resistant focal epilepsy: seizures persist despite adequate trials of 2 appropriately chosen and tolerated antiseizure medications. Video-EEG has localised a left temporal onset and resective surgery is now being considered. NICE recommends considering an additional MRI when surgery is being considered, and specifies that MRI for epilepsy should use a regionally agreed epilepsy MRI protocol. This is designed to improve detection of subtle structural abnormalities, such as focal cortical dysplasia or mesial temporal sclerosis, that may not be shown on an earlier routine MRI. A is wrong because a previously normal routine MRI does not exclude an epileptogenic structural lesion, particularly when surgical assessment is planned. B is wrong because CT has inferior structural detail and is mainly an alternative when MRI is contraindicated. C is attractive because new neurological features can justify repeat imaging, but surgery consideration is itself an indication for additional MRI. E is wrong because failure of 2 appropriate medication schedules defines drug-resistant epilepsy; waiting for a third failure would delay tertiary assessment and potentially curative treatment.

Reference: NICE NG217: Epilepsies in children, young people and adults — Diagnosis and assessment of epilepsy (Updated 30 January 2025) — https://www.nice.org.uk/guidance/ng217/chapter/1-Diagnosis-and-assessment-of-epilepsy NICE NG217: Terms used in this guideline (Updated 30 January 2025) — https://www.nice.org.uk/guidance/ng217/chapter/terms-used-in-this-guideline NICE NG217: Referral to tertiary specialist services (Updated 30 January 2025) — https://www.nice.org.uk/guidance/ng217/chapter/3-Referral-to-tertiary-specialist-services