I had a cortisone injection in my rotator cuff on Wednesday., Two days went by, then on Saturday, the arm that was injected just went numb for a few minutes. First the lower part of my arm, then the upper part of my arm? I was able to vigorously shake my arm, and get the feeling back, but it happened later that night, briefly. Is this just coincidental, is it sign of something more serious, could the doctor have hit a nerve, was this a normal but rare side effect? It's the weekend so my doctor's office is closed. I will call him in the morning, but God, I don't want to think I'm having a prelude to a stroke or heart attack......