Understanding Seizure Types
Clonic Seizures
Clonic movements are repeated, rhythmic muscle jerks. They can affect one region or both sides of the body.
About this information
ESCO reviews this information regularly. It supports learning and does not replace professional medical advice, diagnosis or treatment. Discuss your own care with your healthcare provider.
Understanding the movement
Clonic jerking can occur in focal seizures. Generalized clonic seizures involve both sides and affect consciousness. The movement alone does not determine the classification.
Different from tonic-clonic
A tonic-clonic seizure has stiffening before the jerking. Myoclonic movements are very brief jerks. Clinical assessment helps distinguish these patterns.
Keep the surroundings safe.
Time the seizure, remove hazards and protect the head. Never hold down moving limbs or place anything in the mouth.
When safe, place someone lying down who is not fully alert on their side. Monitor breathing and follow their action plan.
Call 911 for an event exceeding five minutes, seizures without recovery, injury, breathing problems, a seizure in water or a first known seizure.