Facial nerve

Facial nerve (nervus facialis) - VII pair cranial nerves, a mixed nerve.
A large part of the facial nerve - his motor serving originates in the kernel, located in the lid of the bridge. Fiber coming from the kernel, go first in the dorsal direction and follow the core of efferent nerve, then stretch in ventrally and leave the bridge in the cerebellopontine angle. Here facial nerve is located in the medial, from the auditory nerve in the form of more powerful spine itself L. N. and thin spine intermediate nerve [n. intermedins (Wrisbergi)]. Together with auditory nerve he is in the inner hearing the opening of the temporal bone. At the beginning of the channel L. N. (canalis facialis) he is bent at the right angle, forming the outer knee, and out of the skull through Shyla-mastoid bore (Fig). Then L. N. penetrates into the parotid gland, passes through it and forms ahead of the external ear canal plexus, by other branches to mimic muscles of the face. The largest branch of the facial nerve on the face - temporal, buccal, cheekbones, and a branch of the lower jaw; on the neck down a branch that Innervate the skin of the neck muscles.

Facial nerve and its kernel (schematically): and musculoskeletal fiber, b - sensitive fibres, - vegetative fibres; 1 - sphenopalatine ganglion; 2 - n. petrosus superficialis major; 3 - n. intermedins; 4 - nucleus n. facialis; 5 - genu internum; 6 - nucleus salivatorius sup.; 7 - nucleus tractus solitarii; 8 - genu externum; 9 - chorda tympani; VIII - n. acusticus; IX - n. glosscpharyngeus.

Directly to the facial nerve is adjacent intermediate nerve that anatomically is part of L. N. and contains the afferent and efferent fibres. At the outer knee L. N. sensitive part of the interim nerve forms thickening containing cells (ganglion genicyli). Sensitive its fibers are part of the drum strings (chorda tympani), which joins speaking branch of the trigeminal nerve that carries the taste pulses with anterior 2/3 of the tongue. The Central branch is directed to single beam in the brain stem.
Cortical centre L. N. is located in the lower quarter of the front of the Central gyrus. Axons of cortical cells centre, go down, go through the internal capsule. Partly not reaching the nuclei of the facial nerve in the bridge, in part, already at their level gorkovataya fiber cross stitch bridge and come to the cell nucleus L. N. opposite side. Part neprecteny fiber ends at the core of its part. In addition to arbitrary impellent innervation of the facial muscles, via L. N. implemented most of the reflexes of the face - sucking, blink, corneal, conjunctival, Cihelny, nasal.
Facial paralysis is one of the most frequent peripheral paralysis and is due for the most part hypothermia or infection. It develops mainly on one side. However, on the palsy half of the forehead without folds, eyebrow is below the upper eyelid becomes, the eyeball is wider and a bit forward. Eye slit always remains open (logiterm); if you try to close your eyes the eyeball goes up (symptom Bella), eyes constantly Zlatitsa. Nasolabial fold on the paralyzed side smoothed the corner of his mouth dropped. If grin corner of the mouth of drag in the healthy side. The food gets stuck between your teeth and cheek. Accession to the paralysis of the facial muscles disorders taste front 2/3 language indicates the defeat of the facial nerve in his bone canal and the involvement drum strings. The appearance of cold sores on the ear and ear canal points to defeat L. N. level ganglion geniculi.
The disease usually develops acutely. Sometimes the disease or in the first days of pain under jaw and behind the ear. In severe forms of paralysis lasts 6 weeks and more. The presence of electrical excitability of nerve and no reaction rebirth offer hope of recovery even in the long course of the disease. Some patients remain residual effects in the form of a contraction of the muscles on the side of the former paralysis.
From peripheral paralysis of the facial nerve must distinguish it Central or supranuclear, paralysis. At last only paralyzed the lower branch of L. N.; the muscles of the forehead and closing his eyes remain paralyzed, as they have bilateral innervation.
Defeat L. N. observed in many diseases: polio, polyneuritis, neurosyphilis, injuries of skull base and temporal bone, vascular diseases of the brain stem. Facial paralysis may occur at purulent lesion of the middle ear and the decay of the temporal bone. Purulent lesion of the parotid gland surgery on it often entail paralysis L. N. Isolated lesions of its individual branches are found in superficial wounds of the face. Rarely paralysis occurs in newborns when overlaying forceps or pressure on proizvedena person by the normal or pathologically altered pubic articulation of the mother.
Sometimes there are one or two - sided spasms of the muscles innervated by the facial nerve. Jerking or twitching muscles do not depend on willpower, distraction or emotions. Spasm is often limited to a part of the facial muscles (for example, muscle, gripping the eyelids) and gradually captures the entire half of the face. Each twitch starts with 1 spasmodic contractions of certain muscles and then it spreads to all facial muscles half of the face.
Treatment of facial paralysis is first of all to the therapy of the main disease (otitis, syphilis, tumors and other). When "rheumatic" paralysis L. N. shown salicylates (acetylsalicylic acid, amidopyrine, analgin 0.5 g three times a day), vitamin B1 (0.01 g intramuscularly once a day, just 20 to 30 injections), vitamin B12 (intramuscularly in a dose of 500-1000 mg in 7-10 days), neostigmine (0,05% 1 ml under the skin 1-2 times a day for 15-20 days). If signs of infection - penicillin (300 000 IU twice a day, only 6 000 000 UNITS). From the first days should appoint a massage of facial muscles. In the acute period - thermal procedures (UHF, quartz, paraffin). When logofftime need to frequently rinse the eyes with a weak solution of boric acid or sulfacetamide and instill 1-2 drops sterile vaseline or peach oil. After 2 weeks is recommended inegalitarian with iodide sodium. When signs of contraction electric treatments are contraindicated. In the recovery period - medical gymnastics. In case of failure, therapy can be recommended surgical treatment, but not earlier than in 6 months. after the onset of illness. Proposed different types of operations: stapling peripheral end of the facial nerve with the Central end hypoglossal nerve decompression of the nerve, muscle plastic.
Prevention of paralysis L. N. in individuals who already have suffered, is to protect a person from cooling.