a seizure marked by both tonic and clonic motor motions. During the tonic stage the muscles begin to spasm and the person falls to the ground unconscious; breathing might be inhibited or temporarily stopped as well. After this comes the clonic stage, marked by swiftly alternating contracting and relaxing of the muscles, resulting in jaw motions and urinary incontinence.
TONIC-CLONIC SEIZURE: “Tonic-clonic seizures are often referred to as generalized tonic-clonic seizures, and should not be confused with epilepsy, a condition in which they can occur.”