This type of neuropathy among diseases of the peripheral nervous system takes the second place after its helicopterogenic syndromes. An average of 20 people per 100,000 are ill. Among them, only 20% of the suffering is due to otitis media, cerebellar arachnoiditis, fracture of the base of the skull, mumps, ischemia during hypertensive crisis, birth injuries or facial injuries. In the bulk, this is compression of the nerve, the so-called Bell’s idiopathic paralysis of the facial nerve. Some authors believe that cooling and infections can be not only provocative, but also direct etiological factors of the disease. However, in recent years, an increasing number of clinicians are inclined to believe that Bell paralysis is a tunnel syndrome caused by compression of the edematous nerve and its ischemia in the narrow fallopian canal. The conditions for compression are especially favorable in its lower part, where the epineural membrane at the level of the styloid process is thickened and very elastic.
The disease affects people of all ages. The level of nerve damage is more than in observations of the lower discharge of the drum string. The clinical manifestations of facial neuropathy are reduced mainly to paresis of facial muscles. On the sore side, the nasolabial fold is smoothed, the angle of the mouth is lowered and saliva flows from this side. The patient cannot blow out the candle, whistle. The eyelids on the side of paralysis are open – lagophthalmos (cleft eye) due to paresis of the circular muscle of the eye. When squinting through the open palpebral fissure, the sclera of the upwardly retracted eyeball is visible – synkinesia of the eyeball (Bell symptom). A tear constantly flows, the surface of the eye becomes dry. The patient can not wrinkle his forehead, frown at the affected side. A taste disorder is observed in the anterior 2/3 of the tongue, which does not happen if the process is not localized in the nerve trunk (in which the taste fibers pass), but in its motor core in the brain bridge. In the differential diagnosis, the stem symptoms observed in the neighborhood, cross paralysis, etc. are decisive.
Sensitivity disorders are inconsistent and insignificant. There are sensations of numbness in the lips, cheeks, sometimes dull, pressing, less often shooting pains behind the ear or in its circumference, in the cheek, neck, back of the head, along the edge of the lower jaw. Sometimes there is pain in the mastoid process in the zone of the maxillary fossa, in front of the tragus of the ear when the skin folds of the cheek are compressed. Less commonly, mild hypo – or hyperesthesia on the cheek is detected . Pain occurs 1-3 days before the onset of motor disorders, simultaneously with them or after a few days, sometimes weeks. They can hold for several days, weeks, sometimes they last months and years. All these disorders are associated with the involvement of sensitive fibers – the Vrisberg nerve. Most authors consider severe pain to be a poor prognostic sign.
In the absence of pain and a favorable course of the disease (on average in 60-70% of cases), the reverse development of symptoms begins quite quickly, especially with treatment started early. Sometimes there is a rough paresis of the facial muscles, a taste disorder, a feeling of numbness of the cheek, local hyperhidrosis . With slow regression, when lagophthalmos lasts for a long time , the development of keratitis, conjunctivitis is possible. Persistent paresis and paralysis are unfavorable with respect to the prognosis, especially in combination with the symptom of “crocodile tears” (lacrimation when eating and dry eyes when crying). An extremely unpleasant and frequent complication observed in every fourth patient is postneuropathic contracture of the facial muscles. In connection with the emerging shortening of facial muscles (data) gives the impression that the paretic are the muscles are not sick and the healthy side: wrinkles of the forehead on the affected side is more pronounced eye gap already; the nasolabial fold at rest is more pronounced, there are small fibrillations in the area of the chin, twitching of the eyelids. The mechanical excitability of the affected muscles is increased and pathological synkinesia is observed : centripetal – when closing the eyes, the angle of the mouth rises on the same side; eyelid – when closing the eyes, the forehead wrinkles. Contracture often develops in individuals with a non-severe damage to the nerve and with a relatively rapid restoration of facial muscle function, at a high rate of regeneration. In conditions of preserved nerve fibers, irrigation phenomena occur: contracture develops in people with a painful onset of the disease, often in patients with neurosis and hypertension. When kneading the muscles of the cheek between the thumb and forefinger of the doctor, a spasm of these muscles occurs (sign of Duchenne ). The development of contracture of the entire musculature of the cheek may be preceded by the formation of local painful nodules – the muscular nodules of Mueller – areas of compaction without clear boundaries. The timely finding of these painful muscle seals and their kneading often prevents the development of contracture. Thus, the prognosis for the development of contractures determines the consideration of signs of sensory and muscular-tonic irritation. The severity of paresis of the facial muscles is also important. If during the first weeks there are no noticeable signs of recovery, we can assume the presence of irreversible changes in the nerve. With the most profound loss of function of the facial muscles, the reaction of most muscle groups to nerve irritation is completely absent or appears only in individual muscles. In these cases, EMG shows a significant decrease in the amplitude of the oscillations of biopotentials or their absence, and fibrillation potentials often appear. The speed of the impulse along the nerve decreases markedly. On average, in 15% of cases, Bell paralysis recurs (from one to sin times) equally often on the affected (true relapses) and the opposite half of the face. Relapses worsen the prognosis, recovery occurs after a long time or does not occur at all. Recurrent neuropathy, facial nerve (one- or bilateral) and is an integral part of a syndrome Rossolimo- Melkersson -Rozentalya. This syndrome includes, along with Bell’s palsy, a folded tongue and swelling of the cheek. Swelling of the lips or other parts of the face is no different from edema of Meige ( trophadema ). In a limited area of the cheek for several hours or days, a sensation of heat or cold appears, and then dense swelling, over which the skin is reddish with a bluish tint. After repeated attacks, these seals (and deformation of the cheek) become resistant. Among patients with facial neuropathy , Rossolimo- Melkersson-Rosenthal syndrome is noted in less than 0.5% of cases.