A new study shows that even when young hockey players who suffer concussions appear fully recovered, and doctors and trainers return them to the ice, scans still show abnormalities in the brain. The findings were published today in the journal Neurology, and add to a growing number of studies showing that neurological changes linger even after clinical symptoms of a concussion clear up. Athletes may appear back to normal on a battery of cognitive and physical tests, but not on an MRI scan.