Both disease processes in CNS injury shared many similar characteristics like
- The high urine osmolality
- The urine sodium is usually more than 40 meq/L
- Serum uric acid concentration is reduced due to urinary loss
Treatment of hypovolemia with isotonic saline in CSW helps in resolving the issue but same isotonic saline may worsens the hyponatremia in SIADH.
1. Palmer BF. Hyponatremia in patients with central nervous system disease: SIADH versus CSW. Trends Endocrinol Metab 2003; 14:182.
2. Maesaka JK, Imbriano LJ, Ali NM, Ilamathi E. Is it cerebral or renal salt wasting? Kidney Int 2009; 76:934.