What is the difference between SIADH and Cerebral Salt Wasting?

SIADH or Syndrome of Inappropriate Antidiuretic Hormone and Cerebral Salt Wasting are both similar in some ways, especially when you compare the symptoms produced by the two syndromes. Both have been researched to have a common cause, i.e., traumatic brain injury. While cerebral salt wasting is usually caused by subarachnoid hemorrhage due to cases like brain injury, medications, tumors, SIADH also has similar causes but can also be caused by infections and cancers.

The manifestation of SIADH, which leads to the excessive release of the Antidiuretic hormone, usually causes an increase in extracellular fluid volume and the retention of more water. For cerebral salt wasting, the neural input to the kidney is disrupted, causing sodium to be wasted by the kidney, plus the depletion of the extracellular volume.

Although both are associated with hyponatremia, both are usually differentiated in terms of how they can be managed. Fluid restriction is used for SIADH, whereas cerebral salt wasting is managed by constant hydration.

SIADH and Cerebral Salt Wasting are two types of conditions that a person can experience. Both conditions bring on different types of symptoms in a person. One difference between the two is in regards to dehydration. When a person has cerebral salt wasting, they will experience dehydration, whereas with SIADH they will not have any dehydration.

Another symptom in which people can tell the two conditions apart is the amount of sodium that is excreted during urination. With CSW, the amount of sodium in the urine increases, whereas with SIADH the amount of sodium in the urine will vary. It can either increase or decrease.

SIADH or “symptom of inappropriate antidiuretic hormone hypersecretion is a condition in which there is too much water in the body which is caused by the inability of the kidney to release the water in it. This brings about a situation where there is a constant dilution of sodium in the body. This is usually marked by symptoms like confusion, vomiting, headache, nausea, comatose, dizziness, etc.

Cerebral Salt Wasting, on the other hand, is similar to SIADH in terms of signs and symptoms, but it is caused hematoma, brain trauma, injury in the brain, brain tumors, etc. Although cerebral salt wasting has symptoms similar to SIADH, it also causes dehydration due to too much urination. SIADH is usually confirmed by testing for sodium in the blood. Findings like low uric acid, low values for sodium, low BUN, usually confirm the presence of this condition. These two conditions are usually differentiated by checking the concentration of sodium in the urine; a higher concentration of sodium in the urine confirms SIADH.