Hello
@Debj . My husband's consultant did, tentatively mention "atypical alzheimers disease", but I think it was more to describe the fact that my husband just didn't really fit the more common patterns of the disease. For many years, his memory was not too bad, but he had increasing paranoia. He was still very chatty, but would sometimes phrase things a little oddly (when he couldn't find the word for something, he would just find another way to say it). There was one time I remember, I had left him in town, and he was to come home on the bus, as he often did. Only this time, the bus had a different driver than the usual one, so my husband didn't get on! But, he was then able to go to a nearby shop , find my phone number, and have them call me to come and get him.
He didn't start noticeably displaying symptoms like short term memory loss, not recognising people, and loss of skills like reading, writing etc. until the last few years of his illness.