(693) Tales of the Hot and Thirsty: Hypothalamic Dysfunction After Aneurysmal Subarachnoid Hemorrhage

Introduction: Sodium balance disorders namely cerebral salt wasting(CSW) and central diabetes insipidus(CDI) are complications of aneurysmal subarachnoid hemorrhage(aSAH) usually due to cerebral vasospasm. Fluid and sodium losses are treated medically and usually resolve with the vasospasm timeline. New thermoregulatory or other neuroendocrine dysfunction should prompt evaluation of the hypothalamic-pituitary axis beyond hormone testing. The functional organization of the hypothalamus allows signs and symptoms to be traced to a specific anatomic area. We used neuroimaging to diagnose structural etiology of hypothalamic dysfunction and target our medical and surgical interventions.

Description: 48 year-old female presented with severe headache and somnolence who was found to have subarachnoid hemorrhage and hydrocephalus from ruptured posterior communicating artery aneurysm. Bedside ventricular drain(EVD) placed and aneurysm secured by endovascular coiling. On day 6 she developed hyponatremia and polyuria; labs consistent with a mixed neuroendocrine disorder(CSW/CDI). Treated with fluid resuscitation, hypertonic saline, fludrocortisone and desmopressin. Clinical and serial transcranial doppler evaluations were negative for vasospasm. On day 12 EVD was removed followed by worsening of CSW/CDI and development of impaired thermoregulation with intractable rigors. MRI brain with pituitary imaging protocols to enhance visualization of the suprasellar contents showed hematoma compressing the hypothalamus. We added dexamethasone, replaced EVD for CSF diversion to treat irritation and mass effect from subarachnoid blood products. Result was correction of fluid losses and improved temperature profile.

Discussion: Neuroendocrine dysfunction in aSAH resolves along the same timeline as cerebral vasospasm with breakdown of blood products. Sudden worsening of fluid or sodium losses despite adequate management, lack of cerebral vasospasm or new symptoms of neuroendocrine dysfunction should prompt additional investigation. Regulation of temperature, thirst and fluid balance are controlled by anterior hypothalamic nuclei. In this case specialized neuroimaging allowed us to diagnose anterior hypothalamic compression and irritation by SAH blood products and target treatment with corticosteroids and CSF diversion.