He was taken to the university's medical center where he was diagnosed with hypernatremia, too much salt in the blood. According to Medscape, an online resource, this is usually found in the elderly who are mentally and physically impaired. It is most often brought on by "impaired thirst and/or restricted access to water, often exacerbated by pathologic conditions with increased fluid loss."
Eating enough salt to induce hypernatremia is rather rare and usually results in death. The doctors who teated him say that "the patient's peak serum sodium … is the highest documented level in an adult patient to survive an acute sodium ingestion without neurologic deficits."(1) The brain damage can occur because of the brain cells shrink due to the diffusion of water out of the cells.
Chinese food, anyone?
(1) Survival of Acute Hypernatremia Due to Massive Soy Sauce Ingestion, David J. Carlberg, MD, Heather A. Borek, MD, Scott A. Syverud, MD, Christopher P. Holstege, MD, The Journal of Emergency Medicine, June 2013.