Acute-onset isolated oculomotor nerve palsy due to pituitary apoplexy

Pituitary apoplexy (PA) is a neurosurgical emergency resulting from an acute haemorrhage or infarction within the pituitary adenoma. The classic clinical presentations of PA include acute headaches and visual disturbances. However, isolated oculomotor nerve palsy as the first sign of pituitary apoplexy is highly uncommon. We present three cases of acute-onset isolated oculomotor nerve palsy, which were later diagnosed as pituitary apoplexy. One patient presented with bilateral isolated oculomotor nerve palsy, while another had pupil-sparing oculomotor nerve palsy, which is more commonly associated with ischemia than compressive disorders. Our patients recovered completely following an early neurosurgical intervention. Two patients underwent transnasal-transsphenoidal surgery, and one had a transcranial procedure. After surgery, all patients recovered well. Therefore, PA should be included in the differential diagnosis of patients with isolated oculomotor nerve palsy.