If left untreated, a hemifacial spasm can cause all muscles of the face to twitch and spasm. The facial nerve is the only cranial nerve that may show normal post-contrast enhancement, although this applies only to the labyrinthine segment up to the stylomastoid foramen. The facial nerve has six named segments facial nerve segments mnemonic:. Thank you for updating your details. The cell bodies for muscular efferent nerves are found in the facial motor nucleus whereas the cell bodies for the parasympathetic efferent nerves are found in the superior salivatory nucleus.
The temporal branch runs with the superficial musculoaponeurotic system SMAS over the zygomatic arch.
The Facial Nerve (CN VII)
Branches of the facial nerve are responsible for innervating many of the muscles of the head and neck. This information is intended for medical education, and does not create any doctor-patient relationship, and should not be used as a substitute for professional diagnosis and treatment. The motor part supplies somatic motor fibers to the muscles of the face, scalp, and auricle, the Buccinator and Platysma, the Stapedius, the Stylohyoideus, and posterior belly of the Digastricus; it also contains some sympathetic motor fibers which constitute the vasodilator nerves of the submaxillary and sublingual glands, and are conveyed through the chorda tympani nerve. At the bottom of the meatus, the facial nerve enters the facial canal, which it traverses to its termination at the stylomastoid foramen. The facial nerve also supplies preganglionic parasympathetic fibers to several head and neck ganglia. Hemifacial Spasm A hemifacial spasm is a neurological disorder in which blood vessels constrict the seventh cranial nerve, causing muscles on one side of the face to twitch or 'tic' involuntarily. The facial nerve then exits the facial canal and the cranium via the stylomastoid foramen.