AVP and Hyponatremia: This theory is based on the radiographic finding of the dilated ventricle with assumed pressure on the hypothalamus, and resolution of hyponatremia after surgical decompression of the hydrocephalus. Though there appears to be anecdotal evidence in favor of the idea that hydrocephalus-induced hypothalamic release of ADH is real, as of now, there is no animal model to prove the accuracy of this hypothesis.