My limited understanding is that not all viruses affect the brain and related tissues. So you would expect both that the subset of ones which do are of interest

My limited understanding is that not all viruses affect the brain and related tissues. So you would expect both that the subset of ones which do are of interest, and that a plausible explanation for plaques in the brain are reactive to infection, or a side effect of a defence mechanism. Shingles is a remarkably persisting infection. Shingrex and the other vaccines are still new. New enough the cohort with protection are only just moving into the phase where Alzheimers and like problems emerge. So in some respects I would think we are approaching the doorway of epidemiology which might help say if this is a thing or not. (not an epidemiologist, or a virologist, or an anything, I welcome correction on this)