AED Quiz | Episode 19 | Audio Epilepsy Digest

1. What is the safest interpretation of the Roy-Chowdhury post-SEEG results? They establish a predictable year-long antiseizure effect for individual patients. They document seizure improvement in separate last-observation follow-up groups, but those groups do not form a serial persistence curve and do not establish causation. They prove that medication changes did not contribute to the reported outcomes. They establish the number of implanted electrodes as a validated response predictor.

Correct answer: B. The study provides clinically interesting post-SEEG snapshots, but the follow-up groups differ, medication changes were incompletely tracked, and no measured predictor or causal mechanism was established.

2. Which statement correctly summarizes the Lane study? Intracranial monitoring produced a large and significant reduction in daily seizure frequency. Adjusted time to the first seizure was modestly longer during intracranial monitoring, while the difference in daily seizure frequency was not statistically significant. The study isolated electrode implantation from medication withdrawal and anesthesia. The hazard ratio directly measured the probability of long-term seizure freedom.

Correct answer: B. Lane's positive result concerned time to first seizure, with an average delay under one day. It was not evidence of fewer daily seizures or durable clinical benefit.

3. What can be concluded from the Sun scheduled-ECoG analysis? The observed signal changes prove clinical seizure benefit from implantation. The absence of a detected active-versus-sham difference proves stimulation had no effect. ECoG power and spike-rate measures evolved over the first months after implantation, but scheduled-record sampling, surrogate endpoints, and unresolved causation limit interpretation. Constant antiseizure medications eliminated every important confounder.

Correct answer: C. Sun documents an electrographic time course. It does not establish clinical seizure benefit, complete independence from stimulation, or one specific biological mechanism.

4. Why is NAUTILUS used as a design stress test rather than proof of an implantation effect? Because the trial did not implant the sham group. Because all participants were implanted, so the randomized contrast estimates stimulation on a shared implanted background; the prespecified effectiveness endpoint was negative and later post hoc results require crossover context. Because its safety endpoint replaced the effectiveness endpoint. Because the originally sham group remained unstimulated for the entire first year.

Correct answer: B. The implanted-sham design is valuable for estimating stimulation beyond shared surgery and implantation, but it cannot compare implantation with no surgery. The negative primary endpoint remains primary, and crossover complicates later comparisons.

The Implantation Honeymoon: Who Gets the Credit—Implant, Stimulation, or Time?

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