[Hyponatraemia as a clinical manifestation of hypopituitarism caused by neurosarcoidosis].

Severe hyponatraemia was observed in a 35-year-old man with progressive malaise; this was caused by hypopituitarism and secondary hypocortisolism as a result ofneurosarcoidosis. Sarcoidosis is a multisystem granulomatous disorder of unknown aetiology which can develop in any of the body's organs or tissues. The central nervous system is affected in only 5-15% of patients with sarcoidosis. Neurosarcoidosis is a rare disorder with clinical heterogeneity. Extensive diagnostic procedures, including MRI of the cerebrum and histological investigation, and structural outpatient follow-up are mandatory in patients in whom neurosarcoidosis is suspected. Treatment consists mainly of high-dose corticosteroids, which usually have to be taken long-term. Clinical course and prognosis are variable, and depend on the accompanying symptoms.