Isolated Unilateral Abducens Nerve Palsy Manifesting as a Rare Complication of Idiopathic Pituitary Apoplexy: A Case Report.

Pituitary apoplexy (PA) is an expansion of a pituitary adenoma due to infarction or hemorrhage of the gland. The term apoplexy usually describes larger bleeds leading to a sudden onset of symptoms. Although it is a rare condition, it can be a life-threatening emergency. PA usually presents with severe headache, nausea, vomiting, visual acuity, and field defects, frequently involving the cranial nerves directly adjacent to the pituitary gland, including third (oculomotor) cranial nerve, fourth (trochlear) cranial nerve, ophthalmic and maxillary branches of the fifth (trigeminal) cranial nerve, and, less commonly, the sixth (abducens) cranial nerve. Here, we present the case of a 36-year-old male who presented with a one-week history of worsening headache associated with double vision. On physical examination, the patient was noted to have left abducens nerve palsy. MRI brain showed anterior right T1 hyperintensity in the pituitary representing blood products. The patient was treated with analgesics and hormonal therapy with improvement in symptoms and eventual resolution of PA without the need for surgical intervention. PA is an unusual cause of acute isolated abducens nerve palsy which should be identified promptly as it is a life-threatening emergency that can be treated immediately with hormonal replacement followed by a decision to manage conservatively or surgically. The long-term follow-up includes endocrine assessment, visual assessment, and imaging surveillance.