What Causes Numbness Between The Back And Shoulder?

I AM EXPERIENCING THIS FUNNY SENSATION OF VIBRATION IN MY BODY. IT FIRST STARTED FROM THE TOP OF MY HEAD AND WENT DOWN THROUGHT MY BODY. IT CAUGHT ME BY SURPRISE AND I SHOOK IT OFF. RECENTLY I FELT IT IN MY RIGHT ARM. ALSO MY TOP BACK BETWEEN MY SHOULDER FEELS NUMB THROUGHOUT THE DAY. wHAT COULD THIS BE.