Botulinum toxin a injection to facial and cervical paraspinal muscles in a patient with stiff person syndrome: a case report.

Stiff person syndrome (SPS) is a rare neurologic disorder of unknown etiology characterized by increased resting muscle tone, progressive rigidity, and stiffness of the axial musculature. We present a case of a 48-year-old male patient with SPS who experienced facial and neck muscle spasms that were uncontrolled with oral medications and the use of an intrathecal baclofen pump. Botulinum toxin A injections into the bilateral masseter and neck paraspinal muscles provided pain relief and spasm control, illustrating the use of botulinum toxin A injections in the small muscles of face and neck in patients with SPS.