What percentage of frontotemporal dementia cases, characterized by abnormal amounts or forms of tau or TDP-43 proteins accumulating in neurons in the frontal and temporal lobes, are caused by chronic virus infection?

This, too, in essentially all cases, is a viral infection in origin. It is simply a different manifestation of viral presence, and that is a function of individual variability in the makeup and resistance to karmic forces and the interplay when there is a pathogen that gains access and establishes a foothold. Where and when that happens will be a function of inner beliefs, wherewithal to resist, and the karmic forces impinging, and how they might be focused on a particular aspect of the mind. And as that area of the brain handling the input would come into the line of fire, most likely it will be the place where the virus gains an advantage, and then things proceed from there. So this regional abnormality, rather than involving a widespread area of the brain, is not truly a different illness, simply a difference in vulnerability. This is much like arthritis that can happen in multiple joints of the body, but may well manifest solely in the hips as opposed to fingers, or the knee or neck, and not have a large impact elsewhere. And that is quite typical of the interplay with karmic forces and the vulnerability being focused on a particular area or region of the body while leaving other parts undisturbed.