What is facial nerve damage?
Facial nerve lesions are a common pathology in otolaryngology, maxillofacial surgery, sometimes evidence of infections.
Pathological conduction lesions, according to medical statistics, are:
- unilateral nature – 94% in patients with a problem of the facial nerve;
- bilateral character – 6% in patients with similar causes.
A predominantly unilateral lesion of the facial nerve is a feature of the peculiar (characteristic of the VII-pair) innervation of the facial nerve nucleus. The most vulnerable segment of the facial nerve is located in the narrow facial canal of the temporal bone. The facial nerve fills 70% of the diameter of the space of this canal. Disease in this area can result from even a slight swelling compressing the nerve.
Signs of diseases of the facial nerve always appear:
- motor disorders, in the form of changes in the motor activity of the muscles of the maxillofacial zone (paresis and paralysis of facial muscles);
- sensory disturbances, in the form of changes (increased, decreased) sensitivity of the skin and muscles of the maxillofacial zone in the form of a decrease or increase in the pain threshold;
- secretory disorders of the lacrimal and salivary glands;
- internal pain (neuralgia – pain along the nerve), not to be confused with sensitivity to external pain
The main indication of a violation of the facial nerve is paresis, and in severe cases of paralysis of facial muscles, their symptoms and cause disorders of the body systems are detected in all diseases of this nerve.
Facial nerve paresis
A partial decrease in motor activity (voluntary movements) of facial muscles is called paresis, in some cases the term prosoparesis is used to refer to it.
Slight paresis is manifested by minor changes in facial expressions during conversation, severe paresis is manifested by a mask-like face, severe difficulty in performing simple actions (puffing out the cheeks, closing the eyes, etc.).
Paresis of any depth always implies only partial dysfunction of the muscles. This is the most important difference from paralysis. Several options have been proposed for determining the depth of involvement of facial muscles in the pathogenesis and, accordingly, the depth of prosoparesis.
Most often, in the available literature, the variant of determining the degree of functional ability of facial muscles in disorders of the VII-pair of cranial nerves, proposed by American otolaryngologists House WF, Brackmann DE (1985), is mentioned. In 2009, the scale for determining paresis of the facial nerve was improved by them.
Haus-Brackmann six-point system for determining paresis of the facial nerve (1985)
Norm (1 degree)
Facial symmetry corresponds to the morphophysiological characteristics of the individual. There are no deviations in the functions of facial muscles at rest and during voluntary movements, pathological involuntary movements are excluded.
Light paresis (grade 2)
At rest, the face is symmetrical. Arbitrary movements:
- the skin of the forehead gathers in a fold;
- moderate effort when closing the eyes;
- asymmetry of the mouth while talking.
Moderate paresis (grade 3)
At rest, slight asymmetry of the face. Arbitrary movements:
- moderate forehead skin;
- the eyes are completely closed with difficulty;
- mouth, slight weakness with effort.
Medium paresis (grade 4)
At rest, there is an obvious asymmetry of the face and reduced muscle tone. Arbitrary movements:
- the skin of the forehead is motionless;
- the eyes cannot be closed completely;
- mouth, asymmetry, movement with difficulty.
Severe paresis (grade 5)
At rest, a deep degree of facial asymmetry. Arbitrary movements:
- forehead skin, motionless;
- the eyes do not close completely, when closing the pupil rises up;
- the mouth is asymmetrical, motionless.
Total paralysis (grade 6)
At rest, the patient has a motionless, mask-like face (usually one half). There are no arbitrary movements of the skin of the forehead, mouth, eyes.
In some cases, paresis is accompanied by pathological synkinesis – friendly voluntary and involuntary movements of different muscle groups, for example:
- drooping of the eyelid is accompanied by raising the angle of the mouth (eyelid-labial synkinesis);
- drooping of the eyelids is accompanied by wrinkling of the forehead (eyelid-frontal synkinesis);
- closing the eyes is accompanied by tension in the neck muscles (eyelid-platysmal synkinesis);
- winking is accompanied by tension in the wing of the nose of the same side (Guyet synkinesis);
Symptoms of paresis of the facial nerve
Partial impairment of the motor function of the facial nerve in the cortico-nuclear fibers of the cerebral cortex is central paresis.
Central paresis VII – pairs of cranial nerves
They occur with lesions of cortico-nuclear fibers. The consequence of injuries in the cerebral cortex – supranuclear paresis, have characteristic signs, a violation (to varying degrees) of the motor activity of the muscles of the maxillofacial zone, which are manifested by symptoms in the form of:
- paresis (weak mobility) of the tongue, develops on the opposite of the damage to the cerebral cortex simultaneously with muscle hemiparesis (paresis of half of the body);
- paresis of the facial muscles of the lower part of the face, muscles of the upper part of the face;
- all muscles of the face and body on the right or left side.
With minor injuries, facial asymmetry disappears during emotions. The muscles of the face contract involuntarily rhythmically (tic).
Lesions of the nerve fibers of the facial nerve in the peripheral part with partial loss of motor activity are peripheral paresis.
Peripheral paresis VII – pairs of cranial nerves
There are several types of damage along the bundles of the facial nerve (after the nerve nucleus, in the canal of the temporal bone pyramid, tissues of the maxillofacial zone).
Peripheral lesions of the facial nerve are manifested by symptoms:
- asymmetry of facial muscles with a sharp increase during emotions, absence of nasolabial and frontal folds, mask-like face on the affected side;
- decreased muscle tone of half of the face;
- a decrease in the corneal reflex – closing the cornea, conjunctival reflex – closing the conjunctiva, superciliary reflex (ankylosing spondylitis) – closing the eyes in response to their irritation;
- Bell’s symptom or “ hare’s eye ” symptom, when trying to close the eye, his apple moves up, the palpebral fissure does not close;
- the inability to wrinkle the forehead, close the eyes on the side of the lesion, other simple mimic actions;
- half of the face on the affected side is inactive;
- when opening the mouth, the affected half remains inactive;
- liquid food, saliva flows out of the corner of the lips of the affected side;
- possible pain in the ear and face (evidence of involvement in the pathogenesis of the V pair, passing next to the facial nerve in the fallopian canal.
Central and peripheral lesions do not always present with symptoms on the same side of the body or face. Sometimes it is the other way around: true nerve damage on the left side, and symptoms indicating damage on the opposite side.
Topical symptoms describe the involvement in the pathogenesis of specific areas of the facial nerve located at different segments of the nerve pathway (from the brain to terminal neurons – axons or dendrites).
Alternating Miyard-Gubler syndrome
This syndrome is evidence of lesions of the facial nerve nucleus at the level of the trunk and fibers of the pyramidal tract, which manifests itself:
- on the affected side – paresis of the facial nerve;
- on the opposite side – hemiparesis (paresis of half of the body), hemiplegia (paralysis of half of the body).
Fauville’s alternating syndrome
Fauville’s alternating syndrome is evidence of the involvement of the pyramidal pathway of the facial nerve and the abducens nerve (VI pair) in the pathogenesis, which is manifested by:
- on the side of the lesion, paresis (paralysis) of the abducens nerve (that is, the patient’s pupils are turned towards the lesion);
- paralysis of the facial nerve (facial asymmetry).
Involvement in the pathogenesis of the root of the facial nerve is manifested:
- paralysis of facial muscles;
- symptom of defeat of the V pair
- symptom of defeat of the VI pair
- symptom of defeat of the VIII pair
The pathogenesis of the facial nerve above the branch site of the large stony nerve is manifested:
- hypofunction of the lacrimal gland;
- dry eyes.
The pathogenesis of the facial nerve below the origin of the large stony nerve is manifested:
- hyperfunction of the lacrimal gland (lacrimation);
- hyperacusis (increased sensitivity to sounds);
- hypofunction of the salivary glands (submandibular and sublingual);
- paralysis of facial muscles on the same (ipsilateral) side of the lesion of the facial nerve.
The pathogenesis of the facial nerve at a level above the origin of the drum string appears as:
- paralysis of facial muscles;
- taste disturbances.
The pathogenesis of the facial nerve below the origin of the drum string is manifested in the form of:
- movement disorders;
- paralysis of facial muscles;
Causes of paresis of the facial nerve
The multiple etiology of the causes of paresis against the background of a single development of pathogenesis has been proven.
The most common causes of paresis of the facial nerve:
- mechanical damage or breakage of fibers;
- compression of the nerve, as a result:
- infectious, cold or post-traumatic inflammation;
- neuroma (a benign tumor of the vestibular cochlear nerve of the VIII pair of cranial nerves), located next to the facial nerve in the temporal canal;
- toxic ( diabetes mellitus );
- ischemia, cerebral vascular stroke ;
- idiopathic (of unknown etiology);
- medicinal (blockade of the facial nerve with novocaine or its analogs used for conduction anesthesia, in dentistry, otolaryngology, surgery).
Medication interruption of sensitivity is not a pathological cause of exposure to nerve pathways. Blockades are used in the pathogenetic therapy of some stages (pain symptoms) of neuritis.
Complete paralysis of the facial nerve
The total absence of voluntary motor activity of the facial muscles of the face on one or both sides of the head is called complete paralysis of the facial nerve. Unlike paresis, the signs of the disease are more obvious. Paralysis is often a consequence of the invasive development of paresis. Therefore, the central and peripheral disorders of the conduction of the facial nerve largely coincide with the conditions already described in paresis. Paralysis differs only in greater depth of lesions in comparison with paresis.
Symptoms of facial nerve palsy
The severity of symptoms depends on the number of nerve branches involved in the pathological process. Signs of paralysis of the facial nerve:
- asymmetry of the face;
- inability to close eyes;
- lacrimation or lack of tear fluid;
- problems with eating and swallowing saliva;
- inability to pronounce some letters, syllables.
Symptoms of total paralysis of the facial nerve, determined by physical methods:
- mask-like (gloomy) facial expression, ptosis of the corner of the mouth, eyelid, eyebrows on one side;
- not pronounced nasolabial fold, horizontal folds of the forehead;
- the wing of the nose is shifted down, and the tip of the nose is shifted to the opposite part of the face from the lesion;
- thickening of the cheeks, muscle turgor is absent, the texture of the skin is pasty, saggy;
- gaping palpebral fissure, most of the eye is the sclera.
Causes of paralysis of the facial nerve
Factors leading to total paralysis include:
- extensive damage to the facial nerve;
- proximal lesion of the facial nerve – perverted perception of sounds, dry eyes;
- prolonged (more than three weeks) pain syndrome in the mastoid region;
- the development of pathology in persons of the older age group;
- the patient has concomitant diseases (hypertension, diabetes, viral neurotropic diseases), as well as special physiological conditions (pregnancy).
- diseases of the facial nerve at the level of axons (determined by electrophysiological studies).
Neuropathy of the facial nerve
The combined name of the group of diseases of the facial nerve, different nosological groups and etiopathogenesis, accompanied by a violation of the motor, sensory functions of the tissues of the maxillofacial zone, manifested by paresis, paralysis, pain, impaired sensitivity on one or two sides of the face.
Neuropathies, have a negative impact on the patient’s quality of life, are manifested in the form of a combination of previously indicated symptoms:
- Paresis and paralysis :
- give the face asymmetry, violate facial expressions, a person is ashamed of this state, experiences can self-isolate the patient, take extreme forms;
- are manifested by the difficulty or inability of the patient to perform simple actions (movements of the eyes, eyebrows, nose, skin of the cheeks and forehead, etc.) of the right and / or left sides of the face, also cause experiences in a previously healthy person;
- Pain (neuralgia) and impaired sensitivity with damage to the VII pair of cranial nerves stimulate neuroses, dull attention, change the patient’s behavior.
- Violation of the secretory functions of the glands provoke diseases of the organs (eyes, digestion), for which their secrets play an important role.
- Damage to the facial nerve is accompanied by loss of taste, taste is not felt (sweet, salty, bitter).
Numerous symptoms and signs of neuropathies of the facial nerve, or rather its various departments, are described by the patient’s subjective sensations, simple physical research methods. For differential diagnosis, the following methods are used: computed tomography (CT), magnetic resonance imaging (MRI), electromyography, serological methods with the exclusion of infectious diseases, and other methods. The physician is required to know the topography of the nerve pathways, the patterns of nervous responses to stimulation of different parts of the facial nerve. From the patient – a clear description of the sensations.
Symptoms of facial nerve neuropathy
Paresis (paralysis), various changes in sensitivity, pain and other symptoms characteristic of lesions of the facial nerve are common to all diseases of the facial nerve.
Bell’s palsy or neuritis of the facial nerve
The disease is manifested by paralysis of the facial nerve. The reasons are unknown. Considered idiopathic neuritis.
Bell’s palsy symptoms:
- weakness that develops within two days to a maximum;
- pain behind the ear;
- lack of gustatory perception of food;
- hypersensitivity to sounds – hyperacusis;
- there are abnormally many lymphocytes in the spinal punctate – pleocytosis;
Paresis that develops during the first week, does not turn into paralysis, is a sign of a favorable outcome.
Inflammation of the knee node
The knee is a bend with a thickening of the facial (fallopian canal). The facial nerve passes through the canal for about 40 mm, occupying up to 70% of its diameter. Causes of inflammation of the facial nerve node:
- herpes zoster ;
- allergies ;
Symptoms of inflammation of the knee node (synonyms – ganglionitis (neuralgia) of the knee nodes) appear as:
- pain in the ear, radiating to the back of the head, face, neck;
- herpetic eruptions (Hunt’s syndrome) in the area of the tympanic membrane, auricle; other localization of the amygdala, face, head;
- hyperesthesia (increased sensitivity to sounds);
- hearing loss, ringing in the ears;
- nystagmus (involuntary rhythmic eye movements in a horizontal or vertical direction);
- dizziness ;
- disorders of taste;
The disease lasts for several weeks, the prognosis is favorable, and relapses are rare. Possible relapses are due to the lifelong localization of the herpes virus in the nervous tissue and their periodic activation.
The causes of the disease are not fully understood, hypotheses of the causes:
- sarcoidosis – systemic damage to many organs and tissues with the formation of granulomas;
- influenza infection;
- sore throats ;
- injuries (cracks) of the red border of the lips;
- drug intoxication;
- simple lichen ;
- functional disorders of peripheral and central fibers of the cranial nerves
Symptoms of Rossolimo-Melkersson syndrome :
- recurrent paresis of the facial nerve and facial muscles, smoothness of the nasolabial fold;
- edema (swelling) of the lips accompanied by the phenomenon of paresis, sometimes the face in the form of a “ lion’s mask ”;
- folded tongue, resembles the folding of a man’s scrotum, therefore another name is “ scrotal tongue ” from scrotum (scrotum);
- granulomatous cheilitis – granulomatous (autoimmune) inflammation of the red border of the lips;
- migraine pain ;
- neuritis of the facial nerve;
- glossitis – inflammation of the tongue.
The disease occurs in persons of both sexes from adolescence (from 17 years) of life to maturity (up to 60 years), characterized by long periods of the disease. Periods of exacerbations and remissions are characteristic.
Clonic hemifacial spasm
For a long time, the causes of the disease were unknown. Currently proven are:
- compression of the facial nerve by an adjacent artery or vein (neurovascular conflict) is a primary hemifacial spasm;
- tumors, aneurysms, multiple sclerosis, injuries of the lower jaw, hemangiomas (benign tumor) of the temporal bone, vascular malformations – a defect in the form of a fistula between an artery and a vein) is a secondary hemifacial spasm.
The disease is manifested by a painful contraction of the facial muscles of the face identical to the affected facial nerve (ipsilateral side is the same side). Disease symptoms:
- contractions of the circular muscles of the eyes begin rarely, then progress;
- due to the frequency of contractions, temporary loss of vision is possible;
- spontaneous attacks of hemifacial spasms are characteristic;
- contraction of the cheek muscles is an atypical sign;
- symptoms progress during periods of stress, overwork.
The prognosis of the disease depends on the strength of the neurovascular conflict; surgical treatment of the disease and drug therapy are possible.
Facial myokymia is characterized by constant or transient (periodic with a certain rhythm) contractions of facial muscles, which are the result of lesions of the cortico-nuclear pathways of the facial nerve. The reasons are:
- demyelinated plaques;
- malignant neoplasms of the brain;
- multiple sclerosis.
Facial myokymia symptoms:
- pulsation of facial muscles;
- tremor (trembling) of the cheeks.
Causes of facial nerve neuropathy
Neuropathies result from a variety of causes, obvious and idiopathic (non-obvious). Proven causes of facial nerve neuropathies include:
- viral, bacterial, fungal infections;
- compression of the facial nerve by a tumor or arteries (with hypertension)
- vascular malformations of the face;
- systemic diseases;
- hypothermia of the facial nerve;
- pinched nerve with injury to the temporal bone.
Pinched facial nerve
Pinching of the facial nerve is a partial or complete compression of a section of nerve tissue fibers without violating its integrity. Distinguish between temporary (chronic) or permanent (acute) infringement.
Symptoms of a pinched facial nerve
The localization of symptoms in adults and children is often different.
Symptoms of an entrapment of the facial nerve in adults often in the facial canal correspond to:
- Bell’s “ tunnel ” symptom of idiopathic palsy;
- inflammation of the knee node.
- clonic hemycephalic spasm.
All of these symptoms are described above in the text.
Symptoms of a facial nerve entrapment in newborns:
- on the damaged side, the nasolabial fold is smoothed, the eyelids do not close;
- crying is accompanied by pulling the mouth in a healthy direction;
- the search reflex is weakened (Kussmaul reflex): stroke the corner of the child’s mouth with a finger, not the lips, opening the mouth in response and turning the head towards irritation. The reflex will disappear by three months;
- other symptoms are possible (their visualization depends on the localization of the pinched nerve).
The prognosis with timely treatment is favorable. Delaying diagnosis and treatment is unacceptable.
Causes of a pinched facial nerve
Possible causes of pinched roots of the facial nerve in adults and newborns.
Causes of a pinched nerve in adults:
- swelling of the face;
- pathological growth (scarring) of the connective tissues of the face;
- spasms of the chewing muscles of the face;
- temporal bone injuries;
- displacement, dislocation, subluxation of the jaw joints;
- causes corresponding to nerve lesions in the facial canal and neurovascular conflict in clonic hemicephalic spasm.
Causes of a pinched nerve in newborns:
- the result of pathological childbirth, with inept obstetric assistance is possible with the imposition of forceps (cephalic presentation of the fetus);
- the result of physiological childbirth with an abnormally narrow pelvis in primiparous, unavailability of the birth canal, narrowness of the birth canal.
Chilled facial nerve
Neuralgia of the facial nerve (pain in the area of the nerve pathways). Primarily this is a seasonal (late autumn-winter) pathology. Newborns are most sensitive to facial nerve congestion. Chronic neuralgia occurs in the off-season, as well as in the summer, after the usual local cooling of the face (washing with cold water, working or visiting industrial refrigerators in summer and other reasons.
Local cooling of the area behind the ear, accompanied by edema of the tissues of this area. As a result of edema, narrowing ( stenosis ) of the facial canal through which the nerve passes. As a result of nerve compression, pain (neuralgia) of the facial nerve occurs.
The etiology of hypothermia and facial nerve entrapment is different, and the pathogenesis and symptoms generally coincide.
Symptoms of facial nerve congestion
The main (pathognomonic) and first symptom of facial nerve neuralgia is pain in the mastoid region. It is located behind the auricle, palpable (felt) in the form of a tubercle. The pain quickly turns into paresis, in severe cases, into paralysis of facial muscles.
Other symptoms are similar to those of neuropathies (Bell’s syndrome, inflammation of the knee of the facial canal, and others).
Facial nerve treatment
In the acute period of neuropathies of the facial nerve, therapeutic measures are shown with the aim of:
- enhancement of blood and lymph circulation – intramuscular or perineural injections of hormonal preparations of glucocorticoids (prednisolone, dexamethasone and others);
- removal of inflammatory edema – diuretics (furosemide and others) and antioxidants (lipoic acid and others);
- restoring the function of facial muscles, preventing the development of muscle contracture (muscle contraction) – ipidacrine and other cholinesterase inhibitors (neuromidine, amiridin).
During the period of convalescence (recovery) and the chronic course of the disease, therapeutic exercises, massage, physiotherapy, acupuncture, and applications are indicated.
Therapeutic exercises are performed mainly for the muscles of the healthy side:
- dosed tension and relaxation of facial muscles,
- mimic exercises imitating laughter, sadness, joy and others
- training of articulation of sounds (vowels, consonants)
Massage of the healthy side and neck area (stroking, rubbing, light kneading, vibration).
Physiotherapy – indicated during the chronic course of facial nerve neuropathies:
- infrared heat to the affected area (the exposure is determined by the doctor), but no more than 15 minutes per session and no more than 4 times a day. The general course is not more than 10 days.
- Ultra-high-frequency exposure (UHF) in the projection of the branching of the facial nerve in front of the tragus (the process in front of the ear opposite the ear opening), the mastoid process (behind the ear), the area near the outer corner of the eye (the crow’s feet area) Exposure no more than five minutes a day, the total number of procedures up to twelve.
- Low-frequency magnetotherapy, including:
- alternating magnetic field (AMF);
- pulsed magnetic field (PMP);
- running (BeMP);
- rotating (VrMP).
- UHF therapy on the area behind the ear (mastoid area).
- Acupuncture or acupuncture is performed by a trained physician.
All medical manipulations, including medication, have limitations and contraindications. Application is possible only after a thorough examination, obtaining the results of a differential diagnosis, based on the recommendations of a physiotherapist.
With protracted inflammatory processes of the facial nerve, especially at the onset of contractures (contractions) of facial muscles, phonophoresis with glucocorticoid (prednisolone) or detergent (Trilon-B), ozokerite, paraffin applications on the affected area of the facial skin, injections of therapeutic doses of the preparation of botulinum toxin are shown.
In some cases, operative surgical intervention is effective, for example, with a clonic hemifacial spasm.