Trump took the Montreal Cognitive Assesment test. It is meant to detect cognitive disabilty in dimentia or alzheimers patients. This is one page of the test:
Not something that someone with even marginal dimentia couldn't pass.
Also, consider that this same physician - an Admiral who is obligated to follow the orders of the president - also said he was 6'3 and 239 pounds. When he stands next to people who are 6'3, he is significant;y shorter. He is about 6'. He is also closer to 300 pounds than he is to 240.
So while the good admiral is a fine doctor, he has clearly been ordered to report what trump told him to report. The rsults are meaningless because they aren't impartial. For all we know, he never took the test at all.