In addition to the link to the PDF of the Concussion Assessment Tool, I have included a link to and excerpts from the article The Concussion Recognition Tool 5th Edition (CRT5): Background and rationale [PubMed Abstract] [Full Text PDF]. Br J Sports Med. 2017 Jun;51(11):870-871. doi: 10.1136/bjsports-2017-097508. Epub 2017 Apr 26.
And here are excerpts from the article above: