One in a Million: A Woman Presenting with Unilateral Painful Ophthalmoplegia.

Case Presentation: A 52-year-old female presented to the emergency department with four days of right periorbital pain, ipsilateral temporal headache, diplopia, and photophobia. Physical examination of the right eye revealed painful ophthalmoplegia, cranial nerves III and VI paresis, increased intraocular pressure, and mild proptosis. Magnetic resonance venogram and magnetic resonance imaging orbits with contrast demonstrated an abnormal signal surrounding the right cavernous sinus/petrous apex. Tolosa-Hunt syndrome (THS) was diagnosed. Per neurology recommendations, the patient was placed on a steroid regimen over the course of three weeks. She was discharged on hospital day nine following resolution of symptoms. She had no recurrence of symptoms or residual deficits noted at her two-week follow-up appointment. Discussion: With an estimated annual incidence of one case per million, THS is a sinister etiology of unilateral headache, painful ophthalmoplegia, and oculomotor palsy. Tolosa-Hunt syndrome is caused by granulomatous inflammation in the cavernous sinus and is highly responsive to corticosteroids. Magnetic resonance imaging studies of the cavernous sinus and orbital apex are highly sensitive for THS and characteristically show enlargement and focal-enhancing masses within the affected cavernous sinus.