ABSTRACT
Diagnosis of central diabetes insipidus (CDI) requires a high index of clinical suspicion, especially when it manifests as a coexisting condition like traumatic brain injury or following neurosurgery. We would like to report a rare case of necrotizing infundibulohypophysitis (NIH) as a cause of CDI in a 21-year-young male who presented with a severe progressive headache not responding to routine analgesics followed by vomiting, altered sensorium. His baseline blood investigations were normal including his cerebrospinal fluid examination, plain and contrast magnetic resonance imaging (MRI) scan. The patient partially responded to the treatment of headache and after 2 days, complained of polyuria with severely reduced serum sodium level. A repeat plain and MRI of the brain was done which showed classical findings of NIH with CDI which we discuss along with the differential diagnosis and its prognosis