Honestly, how in the holy hell is this not automatically done?? This person is in a pretty powerful position and makes very important decisions. They absolutely need to be coherent. Do they not have some sort of stipulation that if you consistently stroke out on the job and can't even speak or... do anything really, you have to step away from the position until you can prove you are healthy enough to return?
This just blows my mind. Dude could be making monumental decisions that affect the country for decades and not even know what planet he's on.