just a stray here...with a twitch

So I know all you hardcore cat savers are dealing with ferals, but I'm struggling with my stray. I would love to help out ferals, but I haven't seen any in my area and I live in a one bedroom apartment with a recently adopted stray. Her name is Eva and she's the sweetest lady ever. She's been to the vet, been de-flead, no worms!, got all her shots and still loves me after the whole ordeal. My only worry is this tick she has... not like the parasite, like a flinching thing. She'll be sitting on my lap as comfortable as can be, purring, kneading, and her face with twitch. Sometimes the twitches are mild, but sometimes even her lips will twitch. Could this be because she was previously abused? Her twitches aren't triggered by the raising of a hand or anything, they are completely random. I even tested by raising my hand above her head and moving it down like I might hit her, but she didn't get scared or twitch. They seem to be random. Do some cats just have twitches??? or is there something wrong with my lady?? The vet told me she's probably 2 or 3 so she's no old lady. Any advice? What could it be? I've only had her for about a month (during which time she has almost completely socialized, but is still lagging at times). Thanks!

I wondered neurological issues.
http://www.vetinfo4cats.com/catneuro...ng%20in%20cats