Grand mal seizure causes: what to know

A seizure happens when brain cells send abnormal electrical signals together. One event may be provoked by a temporary problem, such as hypoglycaemia, fever, sleep deprivation, a new medicine, or stopping alcohol after regular heavy use. Other seizures arise from epilepsy or a structural change in the brain. A clinician may ask about what happened before the event, recent illness, medicines, alcohol, substances, head injury, and family history.

A convulsion does not identify its own cause. Witness details can help: stiffening, rhythmic jerking, loss of awareness, tongue injury, and confusion afterwards are useful observations. Conditions such as meningitis or alcohol use disorder can require specific assessment, but a seizure alone does not prove either diagnosis.

Arrange medical assessment after a first suspected seizure, even if the person feels well later. Keep a written account of the timing, movements, breathing, recovery, recent symptoms, medicines, alcohol or drug exposure, and any injury. Do not restrain the person, put anything in their mouth, or offer food and drink until they are fully alert. Place them on their side once the jerking stops and stay with them.

Call emergency services if the seizure lasts five minutes or longer, another seizure starts before recovery, breathing does not return normally, the person is seriously injured, the seizure occurs in water, or the person is pregnant or has diabetes. Seek urgent care for a first seizure, a seizure with severe headache, stiff neck, fever, or new weakness, or a prolonged period of confusion.

Ask whether the event sounds like a generalised tonic-clonic seizure, which tests are appropriate, whether a temporary trigger is suspected, and what activities or medicines need review while the cause is assessed.