Here is what we know. Patients with a cognitive impairment like Alzheimer's and Parkinson's are more likely to die of Covid 19. So in evaluating the real risk and human cost of this virus I believe it is crucial to understand what percentage of the elderly who die are that are also suffering from Alzheimer's and Parkinson's which have their own morbidity to factor in.
Thank you for your comments. I have no idea how to select the best response;-)
To Mauro & Ltfi, I agree that this will be done and wish I could set my students on this project. The question is when? It is rather heartless to suggest that closing countries down, changing time-honored customs like kissing and handshakes to save already hopeless cases is futile. And I doubt it is as simple as this but we don't really know.
Customs that trend in a contagion better need be given up to save the future than holding to them.
It is possible mainly in two ways: a) if the subject was diagnosed before any of these neuropathologies -since, once the subject is already suffering from Covid-19, it is difficult, especially at a certain age, to know and differentiate whether said disorders I suffered from them before or if, on the contrary, they are sequelae due to said Covid-19 or to the one known as "Post Covid Syndrome" -eg .: the loss of smell, frequent in Covid, is also frequent and even it is a pathognomonic symptom of Parkinson's; b) by autopsies.
It's possible by investigation of some markers associated with these syndromes like dopamin synthesis pathway in case of Parkinson's syndrome for instance.