Hoshi,
I have been tested for seizures due to dissociating and my neuro recommended I quite driving because of "episodes" that would happen while I was driving.
My EEG came back just fine, I wasn't having seizures and my dissociating had nothing to do with MS.
You don't have a diagnosis of MS so I would not suspect MS as a cause. However, you really should talk to your doctor about what you are experiencing. I hope you get answers soon.
In case you don't fully understand Dissociative Disorders I have provided a link -
http://www.nami.org/Content/ContentG..._Disorders.htm