Brain Spasm - Really?

[RayRae1970]

I am sitting at work, like always, when all of a sudden.... inside my head (in the top, middle, and behind my forehead) I began to feel what seemed to be a muscle spasm.  What?  Rationalizing, I think... Our brains are muscles. Right?  So it could be a muscle spasm.  Whoa... I feel dizzy and lightheaded for a little bit.  Now, I feel like my head is full (stuffed full) of cotton or something. It isn't in my ears.  It wasn't my eyes.  It was "in my head".  WOW.

I experienced this sensation of by brain shaking that was followed by dizziness. The "brain shake" felt like a jolt and then vibration/spasm that lasted about 5 seconds.  I feel like the room is spinning and tilting and I was about to fall over (even though I was sitting down). The dizziness lasted about 2 minutes or so. The weird feeling of fullness in my head is still there.

This was a little scary and concerning. I would be grateful for any insight/input about what might be happening.  THANKS!