Below is a link to a NYT article on people trying to live with Alzheimer’s. The observations in the article line up with my own. If you read the article you will see there is one man profiled who still retains his short term memory but is losing his motor skill rapidly. Then there is a lady who retains her motor skills better but has completely lost her short term memory. Grandpa isn’t so much to one extreme or the other, but those cases reflect how Alzheimer’s progresses differently for every individual.
I would say Grandpa has lost probably short term memory and motor skills in equal measure. He hasn’t lost either entirely, but both are getting progessively worse.
Here is the link: NYT Article on Alzheimer’s