What mental condition or drug can cause constant smiling and lack of blinking?

There is a woman I see occasionally in downtown, she approached me once when I was sitting in the park smoking a cig. I expected a request for a cig or money or something, but no she just talked to me, somewhat inappropriate but not outrageously so(I answered I was from the USA, she said her brother was killed there).

But she has the broadest craziest wide eyed smile the whole time, and she doesn’t blink!(much)

Everytime I see her she has the same crazy smile and beaming eyes without blinking, it is bizarre. I’ve almost got to believe it is drug induced, but I can only think of a strong stimulant.

Do her eyes seem functional? Sufficiently lubricated? Painted on?

Maybe back in 1992 someone rocked her world and she’s been that way ever since.

Functional yes, lubricated yea I guess, she maintains absolute eye contact when speaking to you. I imagine most people would find it threatening, but other than the facial expression nothing suggests hostility.

This is the closest match I found using GIS.

Imagine someone with that expression frozen on their face during chit chat, or any activity.

When I get to grimacing, sometimes I can’t stop it (much to my frustration). Certain neurological conditions are associated with grimacing. Off the top of my head some would be Tourette’s Syndrome, schizophrenia, Parkinson’s disease, and autistic disorders.

But I’m guessing it’s a drug thing.

Wilson’s disease, a copper metabolism abnormality, often causes excessive smiling and grimacing. Dysarthria, dystonia, and tremors are also common. Kayser-Fleischer rings may be seen in the irises. Mental changes and dementia are common.

Weird. I thought of Wilson’s disease (which is a very odd malady) when I saw the OP.
Certainly dementia is an issue here.

Some of her unusual facial tics could be the side effect of certain psych meds. One unpleasant side effect is tardive dyskenesia, and it can be permanent.

It might not necessarily be a “condition,” but rather conditioning. Some people get the idea that they always have to smile to make a good impression. As a result, they end up with a really disconcerting expression on their face, because they’re excessively concerned about looking right. (A lot of politicians do this when they’re in public.) It could be that she’s just trying too hard to be “friendly.”

Williams Syndrome perhaps?

Maybe she’s a victim of the Joker?

Maybe she’s related to that woman at my 50th reunion. In her 60s, and still trying to look like Laura Petrie. Lots of bounciness, giggling, and impromptu breaking-into-song.

Maybe she is in politics. From your description, she sounds like Nancy Pelosi or Michelle Bachmann.

Botox maybe

Sounds like a tweeker to me. Either some stimulant drug or perhaps she has mental issues.

Overly Attached Girlfrienditis?

She has found the Lord. And she’s about to spring it on you.

I had someone plop herself down at my table in a public cafeteria type place (where you can’t expect to keep a whole table to yourself) and talked on and on and on and on…

And then said she was a Moonie and invited me to her church.

That covers smiling, but not infrequent blinking.

A Joan Rivers quality horrible face lift?