Hims symptoms and conditions

My father 64 years old has been on Lipitor for over 2 years. In the past few months he has been very quiet, finding it hard to talk and he knows what he wants to say but some words are hard to say. Severe fatique, he moves much slower, difficulty reading and to understand what he's reading. Finds it hard to write and draw and when he is sleeping he has awful twitching. Is this because of Lipitor? we are waiting for an MRI and EEG the doctor seems to feel it might be dementia or Alzheimer's and maybe so but that all doesn't add up.
Does anyone else feel like this?
Is there hope, we have taken him off Lipitor 2 days ago.
Does anyone have a good result to hear?
How do check to see if Lipitor is the problem where does that show up?