Cranial diabetes insipidus: An interesting case
Miguel Debono & Ritwik Banerjee
Aim: To present a case of a 54 year old gentleman presenting with polyuria and diagnosed with cranial diabetes insipidus.
Methods: The case history, including, detailed results of laboratory tests are presented, and the findings are discussed.
Results: Way back in October 2004 Mr Z.A. was referred to the ENT surgeons with hearing difficulties in the right ear. He was diagnosed with catarrhal otitis media and chronic rhinitis. Symptoms persisted and patient had a bilateral Fess and nasal polypectomy in July 2005. Histology revealed an inflammatory polyp. Since then Mr Z.A noticed increasing polyuria, and polydipsia; this to the extent of waking up repetitively at night to drink or pass urine. These symptoms were very significant; negatively affecting his quality of life. Initial tests showed a serum osmolality of 304 mos/kg and a urine osmolality of 149 mos/kg. All other tests were normal. A water deprivation test was performed and cranial diabetes insipidus was diagnosed. An MRI of the pituitary showed an abnormally looking posterior pituitary gland. Could the development of diabetes insipidus be a complication of the previous polypectomy? This is a possibility when taking into consideration the sequence of events taking place. Or could this be a manifestation of primary familial cranial diabetes insipidus?
Conclusion: Primary cranial diabetes insipidus is rare and secondary causes need to be excluded; Cranial diabetes insipidus post ENT surgery has never been reported but is mentioned as a possible complication of these surgical procedures.