INVERSE MARCUS GUNN SYNDROME – A RARE FACIAL SYNKINESIS

Abstract

Marcus gunn syndrome is one of the most common variety of oculofacial synkinesis. It is seen in 4-6% of congenital ptosis patients. An aberrant neural misdirection appears to exist between motor branch of trigeminal (CN V3) nerve innervating the external pterygoid muscle and fibers of the superior division of oculomotor nerve (CN 3) that innervate the levator palpebrae superioris. Inverse Marcus Gunn syndrome, a very rare variant of synkinesis characterized by lid drooping on masticatory movement and opening of mouth due to the misfiring between 3rd and 5th cranial nerve. An 8-year-old male child presented with congenital ptosis with anomalous drooping of upper lid while eating or opening of mouth.