Persistent hyperprolactinemia, transient hypopituitarism, and transient contralateral third nerve palsy after endovascular treatment of an internal carotid artery aneurysm: Case report and review of the literature.

Intracranial aneurysms have an estimated prevalence of about 3%. A rare subgroup are aneurysms of the internal carotid artery that develop medially into the sellar region. Due to the risk of rupture with subsequent subarachnoid hemorrhage and of compression of surrounding structures, mechanical occlusion is advised. Hypopituitarism is not a rare disease and most often related to pituitary adenoma. Only 0.17% of cases with hypopituitarism are caused by unruptured intracranial aneurysms. Today, the predominant treatment of these aneurysms is endovascular coiling or application of flow diverting stents. We present the case of a 60-year-old female patient, who was treated with endovascular coiling for a right-sided, intracavernous, incidental internal carotid artery aneurysm. On postinterventional day 6, she was readmitted with contralateral third nerve palsy, mild hyponatremia und thyreotropic insufficiency. The symptoms recovered after anti-edematous treatment with corticosteroids; only an asymptomatic hyperprolactinemia persisted. To the best of our knowledge, this is the first case report of transient contralateral cranial nerve palsy combined with transient hypopituitarism after endovascular treatment of an internal carotid aneurysm. As treatment we propose corticosteroids, if necessary in combination with nonsteroidal anti-inflammatory drugs, in order to inhibit inflammatory reactions of the aneurysm wall compromising the nearby, partially compressed neural structures.