Tonic-clonic Seizure
A tonic-clonic seizure usually causes sudden loss of awareness, body stiffening and then rhythmic jerking, followed by confusion or sleepiness. It can be provoked by an acute illness or occur as part of epilepsy.
Key takeaways
- Protect the person from injury, cushion the head, time the event and turn them on their side when possible; do not restrain them or put anything in their mouth.
- A first seizure needs assessment for glucose, infection, substances, medicines, brain disease and other provoked causes.
- Long-term antiseizure treatment depends on recurrence risk, seizure type, EEG or imaging and individual reproductive and health factors.
Catalogue matches are not seizure first aid and do not indicate a safe antiseizure medicine.
What happens after the jerking stops?
The person may be confused, tired, sore or have a headache. Stay nearby, check breathing and avoid food or drink until fully alert. Note preceding symptoms, duration, injuries and recovery for clinical review.
How is medicine selected?
Phenytoin has selected acute and maintenance roles but numerous interactions, concentration-related toxicity and pregnancy considerations. It is not the default treatment for every tonic-clonic event; see neurology.
When to seek urgent care
Call emergency services for a first seizure, one lasting five minutes or longer, repeated seizures without recovery, serious injury, breathing difficulty, pregnancy, diabetes or a seizure in water.