Actually, many states have quite serious programs to screen for drivers developing dementia. So I would focus on that, honestly, if you're serious. A random solo pilot doing a spin/stall crash is far less likely to harm another human than a person having a brain-fart in an automobile. Cars tend to be near other cars. Airplanes are kept separated.

FAA medically qualified the Co-pilot of Fedex Fight 1478 even he was functionally colorblind (red/white) so he can't see PAPI lightrs correctly so we have hardly expext them to correctly qualify a dementia patient.