Effects of water loading in schizophrenic patients with polydipsia-hyponatremia: an MRI pilot study.

We conducted an MRI pilot study of three schizophrenic patients with the syndrome of polydipsia-hyponatremia. Paired MRI scans were obtained at baseline and in the water-loaded state to study the acute effects of water loading and accompanying changes in serum sodium and osmolality on brain structures. We report the pilot data on the observed individual MRI changes of reduced volume of the lateral ventricles in all three patients, and the third ventricles in two patients, in the water-loaded state. These changes were not statistically significant possibly because of small sample size.