Generalized tonic-clonic seizures true HP:0001306 Generalised tonic-clonic seizures Tonic-clonic convulsions Grand mal seizures Tonic-clonic convulsion Generalized tonic-clonic seizures are bilateral and symmetric generalized motor seizures, that occur in an individual with loss of consciousness. The tonic-clonic seizure consists of a tonic (bilateral increased tone, lasting seconds to minutes) and then a clonic (bilateral sustained rhythmic jerking) phase, typically in this order, however variations such as clonic-tonic-clonic and myoclonic-tonic-clonic can also occur. SNOMEDCT_US:54200006 HP:0007252 Generalized clonic-tonic seizures Seizures, tonic-clonic In a generalized tonic-clonic seizure, the patient suddenly loses conciousness, the eyes roll back, and the entire body musculature undergoes tonic contractions. In the clonic phase of the seizure, there are rhythmic contractions of the musculature alternating with relaxation of all muscle groups. Loss of sphincter control during the seizure is common. This form of seizure was formerly commonly called grand mal seizure. Generalized tonic-clonic seizures are generalized seizures with bilateral symmetrical tonic contraction then bilateral clonic contractions of somatic muscles usually associated with autonomic phenomena. Seizures, generalized, tonic-clonic HP:0002069 HP:0002407 Generalized tonic clonic seizures UMLS:C0494475 MSH:D012640 human_phenotype Seizures, generalized tonic-clonic generalized motor onset seizure