Isolated Sixth Cranial Nerve Palsy as Initial Presentation of Pituitary Apoplexy: A Case Report

Abstract

Pituitary apoplexy is a serious condition, which if left untreated, might lead to irreversible life-long complications. Hence, pituitary apoplexy should always be included in the differential diagnoses of a patient with an isolated sixth cranial nerve (CN) palsy. This report highlights the case of a patient presenting with isolated CN palsy associated with pituitary apoplexy. Although pituitary adenomas are common, they seldom present with isolated abducent nerve palsy without any other CN involvement. The 47-year-old female patient presented with acute right eye pain, diplopia, and a squint. Examination revealed an isolated unilateral sixth CN palsy. Brain MRI showed a sellar and suprasellar mass suggestive of hemorrhagic pituitary apoplexy. The patient was transferred to neurosurgery and underwent transsphenoidal resection of a pituitary macroadenoma. Postoperative follow-up showed clinical improvement. It is, thus, imperative for physicians to have the knowledge to recognize an isolated sixth cranial nerve palsy and its associated causes.

Keywords: diplopia; isolated cranial nerve palsy; pituitary adenoma; pituitary apoplexy; sixth nerve palsy.

Figure 1. Axial (A), sagittal (B), and coronal (C) T1-weighted images of sellar/suprasellar oval-shaped homogenous hyperintense mass (arrows), effacing the suprasellar cistern, no cavernous sinus invasion, no definite optic chiasm compression.