Pupil-Sparing Inferior Divisional Palsy of Third Cranial (Oculomotor) Nerve in Tolosa-Hunt Syndrome

Pupil-sparing inferior divisional oculomotor nerve palsy is rare and has not been described in Tolosa-Hunt syndrome (THS). A 24-year-old man with right supraorbital pain and binocular vertical diplopia for 2 weeks underwent full neuro-ophthalmolgical evaluations including brain magnetic resonance imaging (MRI). The patient showed right exo- and hypertropia with impaired depression and adduction of the right eye. The pupils were normal. Other findings of neurological examination and brain MRI were normal. The headache and ophthalmoplegia improved within 2 days of corticosteroid treatment. In view of the pupil sparing, the patient may have a lesion selectively involving the shorter branch of the oculomotor inferior division in the orbit. THS may manifest with pupil-sparing inferior divisional oculomotor palsy.