During a neurological exam for facial pain, twitching, numbness etc she noticed my eyebrows & mouth are asymmetric. what does that mean?

Normal: Asymmetrical means that the right and left sides of your head/face are not perfect mirror images. Don't worry about it though. This is normal for just about every human being on the planet.

Your human: Most people do not believe this but your face and body is asymmetrical and this is normal. Do not be alarmed as this is just your normal anatomy.

Normal: All faces have asymmetry. Likely means nothing.