generalized seizure tonic clonic seizure grand mal seizure The seizures are divided into two phases, the tonic phase and the clonic phase, hence the name of the seizure, though a tonic clonic seizure will often be preceded by an aura. A type of generalized seizure characterised by a combination of tonic stiffening (extensions) followed by clonic flexion motions. MP:0003997 behavior_ontology George Gkoutos 2011-05-27T05:03:11Z HP:0002069 gran mal seizure