Cerebral Salt Wasting

Cerebral salt wasting is a third cause of serum sodium imbalance in individuals with TBI. Like SIADH, cere­bral salt wasting results in hyponatremia. It is essen­tial that cerebral salt wasting be distinguished from SIADH. Unlike DI and SIADH, cerebral salt wasting does not involve the hypothalamo-pituitary system, but is believed to occur due to direct neural effects on renal tubular function. The low sodium levels seen are a direct result of abnormal renal tubular func­tion, resulting in lost sodium along with lost fluid volume. These patients are dehydrated and, therefore, fluid restriction would cause their condition to fur­ther decline. The treatment for cerebral salt wasting involves fluid and sodium replacement (167).