Suggest Treatment For Concussion Syndrome With Numbness In Face

3 months ago I was hit by a car from behind and propelled into the car in front of me while slowing down at a red light. I was diagnosed with a brain injury and concussion syndrome. Now I am feeling numbness on the right side of my face, tongue, chin, neck, and arm. What could it be. These symtoms occur when I move a lot, eat, speak often, but they are not constant and have only appeared since the accident. What should I be concerned about?