tonic-clonic

adjective

ton·​ic-clon·​ic ˈtän-i(k)-ˈklä-nik 

: relating to, marked by, or being a seizure that affects both cerebral hemispheres and is characterized by the abrupt loss of consciousness with initially tonic muscle contractions followed by clonic muscle spasms

During a generalized tonic-clonic seizure, also known as a grand mal seizure, the person might have a vocal outburst, stiffen and fall to the ground.

—Jen Waters, The Washington Times

Most often, though, they [seizures] fall in a well-documented spectrum of mental and somatic anomalies, from the transient episodes of decreased awareness known as absence (formerly called "petit mal") to the tonic-clonic (or "grand mal") attack characterized by loss of consciousness, collapse and spasmodic stiffening and jerking.

—Jerry Adler and Eliza Gray, Newsweek