Suggest Treatment For Slurred Speech And Facial Twitching While Having Dementia

Question: Hi !
I'm visiting my wonderful 91 year old Mom. She has always been very active, hiking, backpacking, tennis, gardening 12 hours/day and took care of my Dad for 8 years from dementia. He died 4 years ago.
She has an active mind and a voracious appetite for reading. She fell and broke her wrist on Mothers day so I've been here helping. I'm seeing things for myself since I'm living here and they are very concerning to me.
Her symptoms are slurred speech, shuffling feet, twitching lip and left side of face,(this is new, past week) her mouth fills up full of saliva and then it pours out so she now has to have kleenex to catch it. If she looks down than she often can't catch it in time. We're talking about a 1/2 cup !! The later symptom is also new as of about 1 month. She often feels nauseous.
She has high blood pressure & Hyponatremia. She takes Atenolol (25 mg, 2x/day) ,Lisinopril,(20mg 2x.day) Lorazapam (0.5mg 3xday). The later was ONLY supposed to be after my Dad had a heart attack,(10 year ago) but they never stopped giving it to her. Now she is dependent upon it which she doesn't like at all ! I'm afraid that this medication may be the cause of her symptoms.
However, it it helps her when she has a "funny feeling in her head", so even though she wasn't supposed to continue it, it DOES help with this feeling. The doctors want her to stay on it due to this. Could be due to blood pressure feeling...not sure...
Also, the slurred speech WAS only at night and then went away, however it is pretty much all the time now.
It gets worse as the day goes on. We haven't had a chance to tell them about the recent excess saliva and twitching, but suffice to say, I'm very concerned.