Hypothalamic-Pituitary Axis Dysfunction, Central Diabetes Insipidus, and Syndrome of Inappropriate Antidiuretic Hormone Secretion as the First Clinical Presentation of Neurosarcoidosis: Why Early Diagnosis and Treatment is Important?

Sarcoidosis is defined by granuloma formation in a multitude of organs. Despite its rare involvement in the nervous system, there are a number of cases that identify neurological symptoms to be the initial clinical manifestation of sarcoidosis. The involvement of the hypothalamic-pituitary (HP) axis presented most frequently with hormone deficiencies. Studies have reported that damage to the pituitary gland may be irreversible, and hormone abnormalities were generally permanent. Neurosarcoidosis has been described as the underlying cause of central diabetes insipidus (DI) and syndrome of inappropriate antidiuretic hormone (SIADH) secretion. The pathological mechanism that can lead both to deficiency and excess of antidiuretic hormone (ADH) secretion is still not fully understood. It has been shown that diagnosis of neurosarcoidosis remains challenging, as symptoms can be inconclusive and diagnostic tools are not sufficiently sensitive and specific. Early treatment may potentially reverse pituitary deficiencies, although studies to confirm this hypothesis are minimal. This review article aims to increase knowledge about central DI and SIADH caused by neurosarcoidosis, identify possible difficulties in diagnosis, and discuss the importance of early management. Clinical trials investigating the long-term therapeutic response in patients with HP sarcoidosis are essential, as there are currently no established guidelines for the treatment of neurosarcoidosis.