BUFFALO, N.Y. — In a dimly lit room off a sobering hospital corridor, Danielle Okposo curled herself in a chair every day and wearily waited for her husband to call out.



Your rings! Your rings!



She would reach out and instantly settle him.



Kyle Okposo couldn’t form full sentences. He was incoherent, confused, paranoid. He strained to recognize loved ones. He thought staffers around his bedside were there to hurt him.



Danielle was terrified. Doctors couldn’t provide answers.



Just over 18 months ago, Kyle suffered a concussion in a Buffalo Sabres workout, but the hit felt so ordinary he wouldn’t be diagnosed for days.



Even with that knowledge, medical experts from Buffalo General Hospital’s neurosurgical department, from the Sabres and from the NHL were unable to explain why Kyle had gone through a manic phase, why the lifelong introvert spent three days calling people from his past to tell them off, why...