Hypernatremia and central Diabetes Insipidus following Neurosurgical procedure of Trauma

The greater risk of hypernatremia in patients over 65 years old are associated with impaired mental status and physical disability which may result in impaired sensation to thirst, impaired ability to express thirst, and/or decrease access to water [1,2]. Normally, anti-diuretic hormone (ADH, also known as arginine-vasopressin, AVP) is secreted in response to 1-2% increase in osmolality which stimulate thirst, as do hypovolemia and hypotension. Broadly, speaking hypernatremia is due to hypotonic luid loss or hypertonic sodium gain. Hypotonic luid loss is mainly caused by diabetes insipidus. There are many causes of central diabetes incipidus (CDI). Pituitary and hypothalamus injuries caused by trauma, neurosurgical procedures, hemorrhage, ischemia, autoimmune diseases e.g. hypophysitis, IgG4 related disease or tumors involving hypothalamic-pituitary axis (HPA) are but few causes of CDI. Central diabetes incipidus is also reported with traumatic brain injuries causing ischemia to the HPA [3] and presented with exertion of large volumes of diluted urine (polyuria). Polyuria is de ined by a urine volume in excess of 2 L/m2/24 h or approximately 40-50 ml/kg/24 h in older children or adult.