Alternatively, numb face may be caused by neuropathy, a disorder in which the nerves that relay signals between the body and the brain do not function properly. Multiple sclerosis is an example of a chronic condition that can result in numbness of the face. Neuropathy or nerve damage can be due to a number of specific diseases and disorders. In many cases, neuropathy has no known cause. In rare cases, if the numb face is accompanied by numbness or weakness of the arms or legs on one side of the body, it can be a sign of stroke. Numbness of the face can also result from injury or, rarely, tumors of the brain or nerves.