Ken Dryden Says Change Can’t Wait: End N.H.L. Head Hits Now January 03, 2018 Bettman +3 Chronic Traumatic Encephalopathy Concussions Dryden Gary Hockey Ice KenIFTTT National Hockey League NYT. Climate Change Bettman Chronic Traumatic Encephalopathy Concussions Dryden Gary Hockey Ice KenIFTTT National Hockey League NYT. Climate Change