Transient epileptic amnesia — SCE Neurology MCQ

Instant feedback + full explanation. One question, done properly.

HardCognitive NeurologyTransient epileptic amnesiaSCE Neurology

A 23-year-old has irresistible daytime sleep episodes, sleep paralysis and brief bilateral knee buckling triggered by laughter while remaining conscious. Overnight polysomnography excludes significant sleep apnoea. Which investigation should follow?

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

Reveal the answer and explanation

Correct answer: D — Prepared multiple sleep latency testing

The best answer is “Prepared multiple sleep latency testing”. Emotion-triggered cataplexy with excessive daytime sleepiness strongly suggests narcolepsy; after adequate overnight sleep has been documented and confounders addressed, MSLT assesses pathological sleep latency and sleep-onset REM periods. “Routine EEG as the sole test for laughter-triggered weakness” is less appropriate because cataplexy preserves consciousness and is not primarily an epileptic event “Dopamine-transporter SPECT for sleep paralysis” is less appropriate because dopaminergic imaging does not evaluate REM-sleep intrusion “Muscle biopsy during an episode of knee buckling” is less appropriate because transient central loss of tone does not reflect a structural myopathy “Carotid angiography for emotion-triggered loss of tone” is less appropriate because the reproducible emotional trigger and sleep symptoms do not indicate carotid hypoperfusion

Reference: NICE NG127: Suspected neurological conditions — recommendations. https://www.nice.org.uk/guidance/ng127/chapter/Recommendations