I had a concussion 6 months ago, since than i'm feeling that my sensations have weakened, i barley have a sense of smell or touch. before that happened i got a strong jolt in my left leg going to the right and than the sensations were gone, same happened in other areas. happened over night. if i overstrain my self mentally i get sick, and losing focus, and feeling like i'm shutting down. what could be the cause. thank you.