I have experienced 2 seizure like episodes. The 1st EEG they did, I did not get in to a good REM sleep during the test, which apparently you need to for a complete test. Therefore, the results came back normal. The 2nd test the insurance co. dragged their feet on and I never had it done. Both times, I was not allowed to drive until either after the test or 6 months of no more episodes.

I from time to time have experienced things similar to what you described - woken up in the middle of the night with my teeth clenched, bitten my cheek, and total body stiffness (only legs, back, and neck - never my arms and hands). Since my EEG was normal, I now just attribute this to spasms and/or some sort of tension.

It is rare, but MSers can have seizures. As mentioned, discuss your concerns with your neuro. I hope you start feeling better soon.