I Lose Feeling In My Legs, Like I Don't Have

I lose feeling in my legs, like I don't have legs from my lower back to my feet, I fall down, and I can't get back up, this last for about 3 hours the last time, I had to call the ambulance and they took me to the hospital, I slur my words, it is just like I had a stroke, but they have cleared me of that, what can be going on with me,