When polyuria does not stop: a case report on an unusual complication of hantavirus infection.

Background: The clinical features, course and outcome of hantavirus infection is highly variable. Symptoms of the central nervous system may occur, but often present atypically and diagnostically challenging. Even though the incidence of hantavirus infection is increasing worldwide, this case is the first to describe diabetes insipidus centralis as a complication of hantavirus infection in the Western world.
Case Presentation: A 49-year old male presenting with severe headache, nausea and photophobia to our neurology department was diagnosed with acute haemorrhage in the pituitary gland by magnetic resonance imaging. In the following days, the patient developed severe oliguric acute kidney failure. Diagnostic workup revealed a hantavirus infection, so that the pituitary haemorrhage resulting in hypopituitarism was seen as a consequence of hantavirus-induced hypophysitis. Under hormone replacement and symptomatic therapy, the patient's condition and kidney function improved considerably, but significant polyuria persisted, which was initially attributed to recovery from kidney injury. However, water deprivation test revealed central diabetes insipidus, indicating involvement of the posterior pituitary gland. The amount of urine production normalized with desmopressin substitution.
Conclusion: Our case report highlights that neurological complications of hantavirus infection should be considered in patients with atypical clinical presentation.