BRAIN SHOCKS!!!

I don't remember when they started happening, maybe sometime like last summer. and have come more and more frequently since then. last night it was a twoforone deal. so the question is: what are they? it feels like my head is having an electrical current run through it, being shaken violently and compressed all at once. it has almost gotten to the point that i enjoy them, they give me a break from the real world. except the weird looks people get when your body convulses and shudders.
most things on the internet say that antidepressant withdrawal causes something similar. I've been off zoloft for three years. granted whenever i quit it i went cold turkey and two years before my therapist ever told me too. funny how you can think of all the right answers, and they all consist of affirmative and positive.
another website i found said it could be brought on by PTSD and stress nowadays. well i fit that description, but still it just seems like something is off. i know trauma supposedly alters your brain chemistry near permanently, but enough that something which seems akin to seizures happens?
thats the other options i've considered. but supposedly you can't feel them, which would rule these out. hurm, dunno......