opisthotonos
- n severe spasm in which the back arches and the head bends back and heels flex toward the back
- She immediately had a severe generalized convulsion with opisthotonos body arched, trismus lockjaw, risus sardonicus a taut, toothy grin, complete extension of the .
- Three constant reactions occur within one to four seconds before the respiratory gaspan increase in muscle tonus, a stiffening of the arms, and a slight opisthotonos arching .