@markdh this all sounds very familiar to what happened with my mother! After doing all of this exact things you mentioned it was determined that she has Lewy Body Dementia with Parkinsonism. She is 83. I don’t know how old your wife is, but a year ago when my mother’s symptoms were slowly progressing, the person who finally gave us answers was a gerontologist. She made the initial diagnosis and then referred us to the neurologist who confirmed an added in the Parkinsonism.