With my husband it was gradual. He had VaD (had major stroke, them lots of TiAs).
Some people thought he could have Lewy or Picks, but we only ever had the VaD confirmed.
He struggled to eat/ swallow, the SALT team and even an Orthodontic Dentist got involved.
Actually, lots of problems eating over a couple of years, before he lost a lot of speech.
Oh.... yes, he used to stop mid sentence too (like Spamar), then lose all interest / track...
I'm not sure about the shouting out in day/ night....it does sound like she is deeper asleep
so isn't waking up distressed or disorientated.....
My husband used to shout out in the day.... panicking looking for me, and I was sat right beside him.
When I answered, he'd sometime jump out of his skin, as he had not seen me sat right next to him.