Sorry, ran out of edit time.
My point is, you really should go to the ER and at least get the CT scan and blood work done. If there is a problem, the results will help you take steps to fix it. I was too tired to care at that point, but my husband took care of me and made sure I got my electrolytes back up (the IV didn’t hurt either). I have a young daughter and don’t want this to happen again. Next time I might fall out of bed and hurt myself. I think this was somebody up there telling me to slow down and take better care of my body.
You should definitely go see a medical professional.
It could be a seizure, but it could also be cataplexy.
The “extending and bending” isn’t something that usually happens, but you mentioned sleep paralysis and that’s something that goes along with cataplexy and/or narcolepsy.
One question, are you on any anti depressants and if so have the doses been modified recently or have they changed your medication in any way. My girlfriend has very similar reactions including arm jerking from her Zoloff.
This.
There’s a strong correlation between sleep paralysis and narcolepsy.
While the incident in the OP may “just” have been a bout of vasovagal syncope (that’s fancy-talk for “you nearly fainted”), and I gather that involuntary movements sometimes happen during a bout of that, it’s definitely something to get checked out.
In the meantime, try to keep some kind of diary of what’s been going on - unusual stress, unusual food, unusual temperature or activities, quanity, time and quality of sleep, etc. This will help you and the doctor figure out what might be going on.
You don’t have to have narcolepsy to experience cataplexy (although they are usually together), but sleep paralysis is part of the same inappropriate activation of the REM sleep muscular paralysis reflex that causes cataplexy.
You can experience cataplexy from SSRI discontinuation or from brain lesions that don’t produce the other narcolepsy symptoms.
This link talks about how the two (seizure, syncope) can resemble each other. It mentions the involuntary movements as well.
Were you confused after the incident or were you mentally aware (aside from the brief time when the attack was happening)?
Cataplexy (which is the condition that’s correlated with sleep paralysis and narcolepsy) could be the issue as well though Doctor Google suggests the circumstances weren’t quite right (usually triggered by something strong/sudden e.g. laughter or exertion).
What it all boils down to, is it could be anything from “whatever, just got dizzy that once” to “you’re going to wake up dead in the morning”. If you can see a doctor at least for an initial consult, it might put your mind at ease, especially if the doctor thinks that more involved testing can wait until the new year. My one bout of syncope, a couple years back, had me going to the doctor, who ran an EKG just to make sure nothing sinister showed up, and it really relieved me.