Is the habit of spitting characteristic of Alzheimer's?

My normally reserved and extremely proper mother would have NEVER picked her teeth with her fingernails in a restaurant. But she did 3 weeks ago when we took her out to eat with my mother-in-law. The dementia can remove inhibitions and allow behavior that they would normally have never done. Maybe this could be the case with your mom.
As said above, some meds can cause excess salivation too.
Is she trying to spit small pieces of food out from between her teeth? Would she benefit from a toothpick?
Give her a box/packet of Kleenex or a small washcloth and have her use it when she needs to "spit". Is the saliva clear? Does she have an odor coming from her mouth? Maybe a dental exam would be in order. You might want to place a disposable pad around the area where she's sitting to catch the fallout.
I think any unusual behavior can be from dementia because they can't think clearly.
Good luck.

Spitting as a symptom with Alzheimer's Disease. Why is this?

Why do some patient with Alzheimer's disease spit intermittently?

to me spitting could be one of the habits they have my husband does it all the time and he only do it when i;m not looking at him. i find that they make some kind of change every 5 or six months they have a new habit. i;ll keep you in my prayer and all the other people who are dealing with people or family who has this disease. may God keep blessing you.

There are a lot of different things people with dementia do. It varies from person to person. I highly recommend the book The 36-Hour Day. It's easy to read and has awealth of information. Good luck.

Llean, symptoms can vary so much among people with dementia. I have heard of spitting on two occasions that I remember. Both were spitting food out, however. It could be that your mother has a special tic of her own, so spits for now special reason. Another possibility is that something may be causing her to salivate too much. Is she taking Aricept or Risperdone? Both these medications, coupled with trouble swallowing, can cause buildup of saliva in the mouth.

If you watch your mother, you'll probably be able to figure out if it is a tic or too much saliva. If she isn't spitting out much fluid each time, I would guess it is a tic that may disappear with time. If each spit is pretty juicy, I'd guess that she is getting rid of excess saliva in her mouth.