Generalised tonic clonic seizures are often preceded by a partial seizure. This is called secondary generalisation. Most tonic clonic seizures occurring in TS are of this sort. Other seizure types Myoclonic seizures are sudden electric shock like contractions of muscles which result in a single sudden jerk of the affected muscles. They can be partial or generalised and can cause a jerk of the limbs, the face or the trunk which may result in falling to the ground.
Drop attacks are seizures in which the child falls or is thrown to the ground.
Drop attacks not infrequently result in nasty injuries such as cutting the chin or back of the head. Absence seizures are seizures in which there is alteration or loss of consciousness without any abnormal movements or convulsions. Typical childhood absence epilepsy or petit mal is not a feature of Tuberous Sclerosis. There are many other abnormal behaviours which can be a result of a seizure. It may sometimes be difficult to determine whether an abnormal behaviour is epileptic or not.