Lewis & Short

ŏpisthŏtŏnos, i, m., = ὀπισθότονος,

  1. I. a disease in which the body is violently curved backwards, a form of lock-jaw (post-Aug.), Plin. 28, 12, 52, § 192; 23, 1, 24, § 48 (written as Greek, Cels. 4, 3, § 3).
  2. II. A disease that causes a person to fall backwards (eccl. Lat.), Hier. 3 Ep. ad Ephes. 6, 4.