AVP and Hyponatremia: Dehydration, iatrogenic factors, syndrome of inappropriate secretion of antidiuretic hormone, and cerebral salt wasting syndrome result in remarkable volume loss that may contribute to the etiology of hyponatremia in neurological diseases (7, 8) Hypertonic fluid gain for the treatment of hyponatremia, diabetes insipidus, and osmotic diarrhea can cause hypernatremia in BM (9).