Pituitary Adenoma Manifesting as an Isolated Abducens Palsy

Abstract

Ocular motor nerve palsies are rare complications of pituitary adenoma. We treated a patient who presented with an isolated abducens palsy and was subsequently found to have a pituitary adenoma. A 62-year-old woman was referred to us for an evaluation of her diplopia. She had an esotropia, which was larger on right gaze, and a limited abduction OD. Visual fields were normal. CT and MRI revealed a sellar region tumor invading the right cavernous sinus without compressing the optic chiasm. A diagnosis of macroprolactinoma was made endocrinologically. Her diplopia and right abducens palsy were quickly resolved and MRI showed significant shrinkage of the tumor after she was treated with cabergoline. A sixth nerve palsy can be the sole presenting feature of pituitary adenoma and can be treated effectively with medication.

KEYWORDS:

• Pituitary adenoma
• abducens palsy
• prolactinoma