Anoxic seizure: meaning and first aid

A person may lose consciousness, stiffen, or jerk after blood flow or oxygen delivery to the brain drops. The episode can resemble epilepsy, but its immediate mechanism and the medical assessment needed may be different.

The brain depends on continuous delivery of oxygen through circulating blood. A sudden interruption, such as fainting linked to a heart rhythm problem, choking, drowning, or cardiac arrest, can cause loss of awareness and involuntary movements.

A clinician needs the sequence of events to separate convulsive fainting, an epileptic seizure, and other causes. Useful clues include posture before collapse, warning sensations, skin colour, breathing, duration of unresponsiveness, injuries, and how quickly normal awareness returned. Low blood glucose can also present with seizure and needs rapid recognition.

Protect the person from nearby hazards, cushion the head, and record the start time. Do not restrain their movements and never place food, drink, fingers, or another object in their mouth.

Check responsiveness and breathing as soon as you safely can. If they are breathing normally after the movements stop, place them on their side and stay with them. If breathing is absent or abnormal, call emergency services, begin CPR if trained, and use an available defibrillator by following its prompts.

Treat suspected oxygen deprivation as an emergency. Call immediately if the person is not breathing normally, remains unresponsive, turns blue or grey, has repeated episodes without recovering, was injured, is pregnant, or the event occurred in water.

A first unexplained seizure-like event requires urgent medical evaluation even after apparent recovery. The assessment may include heart rhythm, blood glucose, neurological findings, medicines or substances, and witness observations; meningitis is a medical emergency when seizure occurs with fever, severe headache, neck stiffness, rash, or marked confusion.

Discuss whether the event was more consistent with fainting, oxygen deprivation, or epilepsy; which heart and neurological checks are appropriate; and whether driving, swimming, heights, or operating machinery should be avoided while the cause is investigated. Bring a witness account or video only if it was captured without delaying first aid.