This video is unavailable because we were unable to load a message from our sponsors. If you are using ad-blocking software, please disable it and reload the page. Embed Code Restart Playing WATCH MORE VIDEOS FROM THIS EPISODE > When Collin woke up one morning and couldn't sit up and had trouble walking, his parents took him to the emergency room. He had hit his head the night before, but tests revealed he didn't have a brain injury. Find out how doctors made a diagnosis. ShareTweet