Atonic seizures (drop attacks) are not seen in many children. Without warning, a child abruptly loses consciousness, collapses and falls to the floor. There is no convulsion, but children may bang their heads as they fall. Recovery occurs after a few seconds. The child regains consciousness, and can again stand and walk.

Atonic seizures may occur with Lennox-Gastaut Syndrome. They sometimes resist anticonvulsant medication. If so, the child may have to wear a helmet to prevent head injuries.