Regarding convulsive events in divers, which is correct?

• A. They almost always have warning signs
• B. They can occur without warning
• C. They only occur in shallow dives
• D. They are unrelated to respiratory status

Answer: (B)

Convulsive events in divers can occur without warning because neurological involvement from diving-related gas problems can strike suddenly. Seizures may result from oxygen toxicity at depth, or from decompression illness or arterial gas embolism that disrupt the brain’s function. While some divers do experience prodromal signs such as tingling, dizziness, or weakness before a seizure, these signs are not reliable or universal. So a convulsive event can appear abruptly, even without clear or immediate warning.

Why this option is the best: it accurately reflects the unpredictable nature of in-water seizures in divers and the fact that they’re not confined to a particular depth or paired with predictable warnings. The other statements don’t fit: warning signs aren’t guaranteed, seizures aren’t limited to shallow dives, and convulsions can be related to respiratory status through oxygen toxicity or gas exchange issues, not unrelated to respiration.