Pituitary apoplexy causing optic neuropathy and horner syndrome without ophthalmoplegia.

A 47-year-old woman presented with headache, acute monocular vision loss, and ipsilateral Horner syndrome. Apart from the optic neuropathy, all cranial nerve function was intact. Magnetic resonance imaging revealed an enlarged pituitary gland with compression of the orbital apex. The surgical specimen was consistent with pituitary apoplexy. The combination of headache, acute visual loss, and ipsilateral Horner syndrome without ophthalmoplegia, which may suggest carotid artery dissection, is evidently an unusual manifestation of pituitary apoplexy.