Isolated trochlear nerve palsy in Tolosa-Hunt syndrome.

A 67-year-old Japanese woman without contributory medical history developed acute onset of left-sided trochlear nerve palsy (TNP) with persistent and severe periorbital pain. There were no other neurological abnormalities. Funduscopic findings were normal. Cranial and orbital magnetic resonance (MR) imaging, and cranial MR angiography demonstrated no abnormalities. By administration of prednisolone 40 mg/day from the day after onset, periorbital pain was resolved within 24 hours, and TNP within 5 days. Thereafter, prednisolone was gradually tapered off. She remained asymptomatic under no medication. In the English language literature, this is the first reported case of Tolosa-Hunt syndrome presenting with isolated TNP.