I moved my mom from assisted living to memory care a couple months ago. She had her vaccines, but one month into memory care she got covid. She did not get very sick physically, but after it was over she suddenly barely recognizes me, has trouble finding the correct words and how to pronounce them when she does recall them, and responds to questions with "I don't know. What do you think"? She is also having trouble walking, even with her walker. It is sad to see her like this. Her doctor doesn't seem to know if covid caused it or if it is just the progression of Alzheimer's.
My aunt with late stage Parkinson’s had Covid along with four other family members. They had varying degrees of illness, symptoms. She had the lightest case but did develop large blisters. That was her only known symptom. She was in a recovery mode from a fall that had set her back when she contacted Covid. She has never gotten back to that base. Her husband, my uncle, was hospitalized with it twice (cousin thinks he had it twice). He is now on hospice and while he looks good, his dementia really progressed. As with all things relating to dementia and now Covid, so very much a mystery. I’m sorry for her decline.
Her post-Covid issue seems to be unexplained bruising. She keeps breaking out in bruises and blood blisters for no reason, and her hospice nurse says Mom is the third patient she's had who developed that problem after Covid.
I am sorry, best wishes.