tonic-clonic seizure, an epileptic seizure characterized by a generalized involuntary muscular contraction and cessation of respiration followed by tonic and clonic spasms of the muscles. Breathing resumes with noisy respirations. The teeth may be clenched, the tongue bitten, and control of the bladder or bowel lost. As this phase of the seizure passes, the person may fall asleep or experience confusion. Usually the person has no recall of the seizure on awakening. A sensory warning, or aura, can precede each tonic-clonic seizure. These seizures may occur singly, at intervals, or in close succession. Anticonvulsant medications are usually prescribed as prophylaxis against tonic-clonic seizures. Also called grand mal seizure. Compare absence seizure, focal seizure, psychomotor seizure.
