As a part of an endoscopic brow lift, the nerves that gives sensation to the scalp are identified and the tissue around the nerves is released in order to get the lift needed. It is not uncommon when doing this to bump up against the nerves. Occasionally, when the nerve is touched, it can stop working for a while (which is why you got the numbness). If the injury was bad enough, sensation through the nerve may be abnormal (the burning which you are experiencing). At this point there is not much you can do about it. Hopefully, as time goes on the burning sensation will resolve. Try and be patient. It's really your only option at this point. Good luck.