Endocrine Abstracts

Introduction

Sarcoidosis is a multisystem disorder, characterised by the presence of non-caseating granulomas. 5–13% of cases involve the nervous system. Neurosarcoidosis carries a poor prognosis and can lead to an infiltrative process in the hypothalamo-hypophyseal region, resulting in panhypopituitarism and central diabetes insipidus (DI). These are rare but serious complications of neurosarcoidosis.

Case

A 26-year-old female with no past medical history was found unresponsive at home. While being transported to hospital in an ambulance she suffered a cardiac arrest. She was treated with two minutes of CPR and one shock for ventricular fibrillation. On arrival to the emergency department she was intubated, ventilated and admitted to ICU. Initial biochemical evaluation revealed deranged electrolytes: potassium 2.4 mmol/l, sodium 124 mmol/l and magnesium 0.68 mmol/l. ECG was abnormal with a prolonged QTc of 535ms. A collateral history revealed amenorrhoea, weight-loss and fatigue over the preceding 6 months. Pituitary hormonal evaluation prior to treatment was consistent with panhypopituitarism: thyroid-stimulating hormone: 0.29 miu/l, free-thyroxine: 9.8 pmol/l, ACTH: <2 n g/l, IGF1: 34 mg/l, oestrodiol: <92 pmol/l, FSH: <0.5 iu/l, with an inappropriately normal cortisol (331 nmol/l) for the concurrent illness. Following admission she developed polyuria of 10 litres/24-hours and repeat biochemistry testing revealed a fast rise in sodium to 141 mmol/l. DI was diagnosed based on evidence of significant polyuria, rapidly rising sodium and clinical improvement with a combination of frequent subcutaneous and oral desmopressin with IV hydrocortisone. Initial CT imaging revealed diffuse infiltrations in the liver and spleen. Liver biopsy confirmed non-necrotising granulomatous inflammation. Lumbar puncture showed elevated protein of 716 mg/dl. MRI-brain demonstrated thickening of the meninges, particularly enhancement of the pachymeninges around the skull base and pituitary infundibulum, in keeping with neurosarcoidosis. MRI-cardiac revealed increased intensity in the myocardium, consistent with sarcoidosis. CT-PET confirmed active sarcoidosis in the liver and spleen. Following a diagnosis of multisystem-sarcoidosis with panhypopituitarism and central-DI, treatment was initiated with intravenous corticosteroids, hormonal supplementation (desmopressin, levothyroxine) and immunosuppression (methotrexate, infliximab). An ICD was inserted for the prevention of sudden cardiac death. Over the following weeks she demonstrated a positive response to treatment with improved energy levels, normalization of electrolyte and hormone levels and resolution of polyuria.

Conclusion

Panhypopituitarism and central DI secondary to neurosarcoidosis is a rare clinical manifestation that should be considered in patients presenting with symptoms of neuroendocrine dysfunction. Immediate treatment with desmopressin, corticosteroids, thyroxine and immunosuppressants can prevent rapid decline and loss-of-life.