Description
The normal posterior pituitary contains enough ADH (antidiuretic hormone) to last 10 days. When traumatised, an acute neuropraxic injury can cause immediate onset cranial diabetes insipidus, followed a few days later by release of ADH from damaged neurohypophysis, leading in effect to a syndrome of inappropriate ADH secretion. When the ADH reserve has been fully exhausted, cranial diabeted insipidus supervenes once again. Although a rare occurrence, readers need to familiarise themselves with this ‘triple response’, not least because of the potentially dangerous phase of SIADH.
