What Causes Numbness In The Mouth And Teeth?

My entire body and sometimes my brain feels like it is either being slammed into a brick wall, or being electrocuted. There is no pain. It happens almost constantly when I am awake. Sometimes, it knocks me off balance and causes my mouth and teeth to go numb. Each episode lasts only seconds, but they are continuous. I can carry on a conversation while having these episodes. No one else seems to notice, unless they are severe, except me. HELP!