Background: True diabetes insipidus (DI) is a rare disease in children, defined as the excretion of hypotonic urine and polydypsia, secondary to an absolute or relative deficiency of antidiuretic hormone arginine vasopressin (central DI) or a resistance to the action of this hormone (nephrogenic DI). To differentiate from primary polydypsia.
Objective and hypotheses: We report the case of AM a 13 years old girl, with personal history of cholecystectomy at age 8 years, who present polyuria and polydypsia syndrome evolving for 4 years without identifiable precipitating factor, amounted to 5.5 l/24 h, associated with visual disturbances witch evoke craniopharyngioma nevertheless without symptoms of intracranial hypertension.
Method: Cerebral MRI, the water deprivation test and ophthalmologic examination were performed.
Results: Cerebral MRI does not find evocative mass and shows a persistent hyper posterior pituitary signal in T1, without thickening or infiltration of the pituitary stalk. The water deprivation test showed a concentration of urine after 3 h, in favor of the diagnostic of primary polydypsia. Ophthalmologic examination found a bilateral decrease in visual acuity associated with astigmatism and amblyopia.
Conclusion: Asssociation of visual impairment and a polyuria syndrome in children must suggest first a craniopharyngioma, pituitary MRI permit to invalidate this diagnosis, primary polydypsia is retained only as diagnosis of exclusion as this is the case for our patient.
20 - 22 Sep 2014
European Society for Paediatric Endocrinology