Endocrine Abstracts

Introduction: Inferior petrosal sinus sampling (IPSS) is the gold standard test to differentiate Cushing’s disease from ectopic Cushing syndrome. IPSS may cause severe complications; however, overall rates are low. Subarachnoid hemorrhage (SAH) has been rarely reported after IPSS. Here we report a case who developed hypertensive emergency, left 6th cranial nerve palsy, and SAH after IPSS.

Case: A sixty-two years-old female patient had a history of hypertension, ischemic cerebrovascular incident, coronary artery disease, and atrial fibrillation. She was diagnosed with bilateral adrenal incidentalomas five years ago, a right-sided 20 × 13 mm and a left-sided 40 × 40 mm adenoma. She did not exhibit typical features of Cushing syndrome but had high levels of salivary and 24-hour urinary cortisol. Serum cortisol was not suppressed with low dose dexamethasone (DXM). High dose DXM testing demonstrated less than 50% suppression. Adrenal venous sampling was unsuccessful. Left adrenalectomy was performed. Pathology showed nodular hyperplasia. The laboratory evidence of hypercortisolism vanished after surgery. Her follow-up was unremarkable until 2019 when she suddenly started experiencing hypertensive episodes. The evaluation revealed biochemically recurrent Cushing. ACTH was not suppressed but was in the gray zone and increased after CRH. High dose DXM testing suggested Cushing Disease. Hypophyseal magnetic resonance imaging (MRI) revealed a right-sided 4 mm adenoma. IPSS was planned. She was on apixaban, which was switched enoxaparin. There was no technical problem during IPSS. About an hour after the procedure, she developed acutely elevated hypertension (180/100 mmHg), headache, and vomiting. Her Glasgow-coma scale point was 15, without any deficits. Her blood pressure (BP) could not be controlled with oral medication; she was transferred to the ICU for intravenous nitrate infusions. Four hours following the procedure, her BP was still uncontrolled, and she developed a left-sided 6th cranial nerve palsy without any visual disturbances. A head scan revealed widespread hyperdensities in the subarachnoid space and ventricles. Her BP treatment was intensified with subsequent successful control. Cranial MRI excluded acute cerebrovascular incident. Her symptoms gradually improved. Nerve palsy dissolved after 48 hours. Follow-up imaging on the fourth day showed that hyperdensities had entirely resolved. She was discharged without any sequel. IPSS results were lateralized to the adenoma side. She is planned for surgery.

Conclusion: Hypertensive emergency and SAH after IPSS are rare but not unexpected. To our knowledge, this is the first case of transient 6th nerve palsy after IPSS. Physicians should be prepared for these uncommon presentations after IPSS.