[Etiological diagnosis of central diabetes insipidus: about 41 cases]. / Diagnostic étiologique du diabète insipide central: à propos de 41 cas.

The occurrence of polyuria-polydipsia syndrome with hypotonic urine requires careful diagnostic strategy. This study aims to evaluate diagnostic modalities for central diabetes insipidus. We conducted a retrospective study of 41 cases with central diabetes insipidus (CDI). Data were collected at the Department of Endocrinology, University Hospital La Rabta, Tunis, from 1990 to 2013. We identified the circumstances for detecting CDI, the abnormalities in anterior pituitary assessment and pituitary imaging. CDI occurred in the postoperative period in 20 patients. The average urine 24-hour volume was significantly higher in patients with CDI outside a surgical setting. Water deprivation test was successful in all patients who benefited from it. Outside of neurosurgery, infiltration causes were found in 6 patients and tumor causes were found in 6 patients. CDI was associated with empty sella turcica in 1 case and idiopathic sella turcica in 3 patients. Hypothalamic-pituitary magnetic resonance imaging and anterior pituitary balance sheet are systematic outside pituitary surgery setting and obvious primary polydipsia.

A case of transient central diabetes insipidus after aorto-coronary bypass operation.

Diabetes insipidus (DI) is characterized by excessive urination and thirst. This disease results from inadequate output of antidiuretic hormone (ADH) from the pituitary gland or the absence of the normal response to ADH in the kidney. We present a case of transient central DI in a patient who underwent a cardiopulmonary bypass (CPB) for coronary artery bypass grafting (CABG). A 44-yr-old male underwent a CABG operation. An hour after the operation, the patient developed polyuria and was diagnosed with central DI. The patient responded to desmopressin and completely recovered five days after surgery. It is probable that transient cerebral ischemia resulted in the dysfunction of osmotic receptors in the hypothalamus or hypothalamus-pituitary axis during CPB. It is also possible that cardiac standstill altered the left atrial non-osmotic receptor function and suppressed ADH release. Therefore, we suggest that central DI is a possible cause of polyuria after CPB.

Hypocalcemia due to tubular dysfunction in a patient with holoprosencephaly.

This is the first report of a case of hypocalcemia in a female infant with holoprosencephaly. Hypocalcemia developed 60 days after birth, secondary to decreased serum 1,25-dihydroxyvitamin D, as a result of renal tubular dysfunction which may have been induced by prerenal acute renal failure, the administration of anticonvulsants, and hypothyroidism. However, there was no evidence of rickets, and her serum 25-hydroxyvitamin D value was normal. She was treated with high-dose (0.5 microg/kg) 1alpha-hydroxyvitamin D3 and calcium lactate, and her calcium and 1,25-dihydroxyvitamin D values were consequently, normalized. However, she died at 268 days after birth.