opisthotonos opisthotonos /oʊˈpɪsθəˌtoʊnɒs/

noun

1. Severe spasm in which the back arches and the head bends back and heels flex toward the back  ( opisthotonos )
   severe spasm in which the back arches and the head bends back and heels flex toward the back
    The patient displayed symptoms of opisthotonos, causing great concern among the medical staff.
   The patient displayed symptoms of opisthotonos, causing great concern among the medical staff.