Diabetes insipidus: occurrence after minor head trauma.

Post-traumatic diabetes insipidus is a rare entity, usually associated with severe head trauma, often with skull fracture and cranial nerve dysfunction. A 24-year-old male presented to a medical clinic 2 weeks after a minor head injury with presenting symptoms of polyuria with nocturia and intense polydipsia. A diagnosis of post-traumatic diabetes insipidus was made. Although other causes of polyuria syndromes must be ruled out, plotting urine versus plasma osmolalities can provide rapid preliminary diagnostic help when considering diabetes insipidus. First-line treatment should include a trial of chlorpropamide and hydrochlorothiazide. Caution should be exercised in not overlooking associated anterior pituitary damage, which may develop several years post-trauma.