PSAT053 An Unusual Case of Central Adrenal Insufficiency Following the Diagnosis of Presumed Neuro-Sarcoidosis

BACKGROUND: Central adrenal insufficiency develops due to inadequate ACTH secretion by the pituitary gland (secondary) or decreased corticotropin-releasing hormone (CRH) secretion by the hypothalamus (tertiary).(1) The hallmark of central adrenal insufficiency is inappropriately low levels of ACTH in the setting of low cortisol levels.(1) Central adrenal insufficiency can be caused by CNS processes affecting the hypothalamus or pituitary gland, such as infection, autoimmune disease, malignancy, or the abrupt cessation of steroids.(1) Here we present a rare case of central adrenal insufficiency following the diagnosis of presumed neuro-sarcoidosis. CLINICAL CASE: A 69-year-old female presents with fatigue, weight loss, and diffuse bilateral weakness. Vital signs were within normal with a physical exam significant for 3/5 strength in bilateral upper and lower extremities. MRI brain revealed leptomeningeal and pituitary stalk enhancement. CSF studies showed CSF lymphocytic pleocytosis and an elevated CSF ACE level 5.8 U/L. The most common etiologies of an elevated CSF ACE level are neuro-sarcoidosis or malignancy, and patient had no imaging findings of malignancy. With the elevated CSF ACE level along with imaging findings, she was given a presumptive diagnosis of neuro-sarcoidosis. She was treated with three days of IV methylprednisolone with mild improvement in symptoms. After discharge, she continued to have symptoms of diffuse weakness, fatigue, nausea and was re-admitted a few weeks later. Vitals on this admission revealed hypotension to 93/55, heart rate 66, SpO2 99%. Repeat MRI brain revealed resolution of leptomeningeal and pituitary enhancements. Due to the hypotension, morning cortisol levels were drawn and returned low at 0.4 ug/dL. ACTH stimulation test showed cortisol at 0 minutes low at 0.5 ug/dL and cortisol at 60 minutes at 9.7 ug/dL. ACTH prior to stimulation test returned low at 1.6 pg/mL. With reduced ACTH levels in the setting of low cortisol levels, the patient was diagnosed with central adrenal insufficiency. She began hydrocortisone treatment with complete resolution of symptoms. Further pituitary hormones were tested with TSH returning low at 0.04 uIU/mL; free T4 normal at 0.8 ng/dL; T3 low-normal at 39 ng/dL; FSH low for a post-menopausal female at 2.8 mIU/mL. This multi-hormonal insufficiency suggested the presence of an intracranial process contributing to hypothalamic-pituitary dysfunction. With initial neuro-imaging findings and elevated CSF ACE, the intracranial process causing her central adrenal insufficiency was presumed to be neuro-sarcoidosis. Due to resolution of symptoms on hydrocortisone therapy, definitive histologic evidence of neuro-sarcoidosis was not pursued. CONCLUSION: This is a case demonstrating a rare presentation of central adrenal insufficiency following the diagnosis of presumed isolated neuro-sarcoidosis, with symptoms and radiographic findings responding rapidly to steroid therapy. REFERENCES: Nicolaides, N. C., Chrousos, G. P., & Charmandari, E. Adrenal Insufficiency. [Updated 2017]. In: Feingold KR, Anawalt B, Boyce A, et al., editors Endotext [Internet]. Presentation: Saturday, June 11, 2022 1:00 p.m. - 3:00 p.m.