'Convulsions' in the Bible

So they brought the boy to him. When the spirit saw Jesus, it immediately threw the boy into convulsions. He fell on the ground and kept rolling around and foaming at the mouth.

Without warning a spirit takes control of him, and he suddenly screams, goes into convulsions, and foams at the mouth. The spirit mauls him and refuses to leave him.

Even while the boy was coming, the demon knocked him to the ground and threw him into convulsions. But Jesus rebuked the unclean spirit, healed the boy, and gave him back to his father.