AVP and Hyponatremia: The incidence of hyponatremia in the present study was also within the scope of previous studies (66.7 vs. 39–80%, respectively) (8, 11, 17, 25, 26, 28, 29); hyponatremia is often caused by inappropriate secretion of the antidiuretic hormone, which may be related to the expression of LGI1 in the hypothalamus and the kidney (31).