I developed EPM in June 2011.
I've created a blog regarding it: whatishyponatremia.org
I highly recommend researching it.
It contains information regarding medical research. Information about what's happened to me and how it's impacted my life, and it includes what others are experiencing with it.
It talks about the different causes, the most common hyponatremia, but also cardiac disease, certain medications like BP meds, antidepressants, etc, renal issues and liver problems.
Most often CPM/EPM is caused by the incorrect treatment of hyponatremia. That said, if that's what happened to him, his doctors might hope that he dies before you find out more about it.
Depending on the severity of symptoms, he might get better or he might get worse. There's a significant risk of death during the first 3 months...as the weeks go by, the risk for death decreases.
However, symptoms can also continue to evolve for years after the initial injury. (This is debated by some doctors, but my research has found that after the initial injury, as the brain heals, more damage can occur which causes later onset symptoms.)
It is typically broken down that 1/3 of people die initially, 1/3 get better to some degree, and 1/3 remain with ongoing disabilities.
Please check out my blog for over 40 posts of medical information regarding it. I try to keep the medical issues separate from my more personal story with it, so that you can use it as a research tool.
I wish him the best of luck...oh, also you can talk to additional people who have it on Inspire.com...Inspire is an online support group for everything from eating disorders to extremely rare diseases and injuries, like CPM/EPM. Do a search on CPM on Inspire's website, and you'll find posts from people who have it.
Best of Luck,
Sarah M.