Facial muscle contraction in response to mechanical stretch after severe facial nerve injury: Clapham's sign

Abstract

Following severe or complete denervation, contraction of the facial muscles following mechanical stretch provides evidence of preservation of activity in the facial muscle's excitation-contraction apparatus. Further research will investigate the clinical significance of this sign and whether it can be used as an early predicator of the development of synkinesis, as well as its relevance to facial nerve grafting and repair.