Convulsive pre-syncope and muscle spasms?

Hi I’m not diagnosed but I’m looking into POTS with doctors currently! I’ve been having episodes where I feel very close to fainting, I’m shaking a lot, I have severe twitching issues, and my right leg specifically gets really tight. There’s also the classic symptoms of feeling very dizzy, my heart racing, my vision being hard to focus, etc. Could this be convulsive pre-syncope?

I’m here asking about this because I just saw something about convulsive syncope and saw other people say they experience convulsive pre-syncope, but I can’t actually find anything about it online. I’ve only actually fainted once, but I come close to it rather often now. I have lots of episodes of heart racing, dizziness, and instability without the twitching and spasms. My episodes are becoming more severe and frequent, so I’m trying to find out as much as I can.