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Ictal SPECT SISCOM – Epilepsy Localisation — SCE Neurology MCQ

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HardClinical NeurophysiologyIctal SPECT SISCOM – Epilepsy LocalisationSCE Neurology

A 55-year-old man with drug-resistant focal epilepsy has undergone video-EEG telemetry. Three habitual seizures were captured. All arose from the right temporal region with consistent semiology. His MRI is non-lesional. PET shows right temporal hypometabolism. Neuropsychological assessment shows left-hemisphere dominant language with adequate contralateral memory. What additional test may help lateralise the seizure onset zone?

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Correct answer: B — Ictal SPECT with SISCOM (subtraction ictal SPECT co-registered to MRI)

The best answer is “Ictal SPECT with SISCOM (subtraction ictal SPECT co-registered to MRI)”. NICE bases epilepsy diagnosis and treatment on seizure type, syndrome, recurrence risk, comorbidity, pregnancy potential and medicine harms; typical provoked seizures are managed by correcting the provoking cause. The alternatives “Serum prolactin, after excluding important mimics, after specialist assessment”, “Lumbar puncture, after specialist assessment, when the phenotype supports it”, “Carotid Doppler, when the phenotype supports it, within the relevant UK pathway”, “Chest X-ray, within the relevant UK pathway, after excluding important mimics” are clinically adjacent possibilities, but they do not match the defining chronology, localisation, physiology, investigation result or UK management sequence in this stem.

Reference: NICE NG217 epilepsy recommendations: https://www.nice.org.uk/guidance/ng217/chapter/Recommendations