Causes of pain in the face

The most frequent cause of pain in the face is trigeminal neuralgia. The prevalence of trigeminal neuralgia is quite high and amounts to 30-50 patients per 100 000 population, and the incidence according to WHO is in the range of 2-4 people per 100 000 population. More often neuralgia of the trigeminal nerve occurs in women 50-69 years old and has a right-lateral lateralization. The development of the disease contributes to various vascular, endocrine, allergic disorders, as well as psychogenic factors. It is believed that trigeminal neuralgia is an idiopathic disease. However, there are several theories explaining the pathogenesis of the disease. The most likely cause of neuralgia of the trigeminal nerve is the compression of the trigeminal nerve at the intra- or extracranial level, and therefore distinguish neuralgia of central and peripheral genesis.

Intracranial causes of compression may be a volumetric process in the posterior cranial fossa (tumors: neurinoma of the auditory nerve, meningioma, glioma of the bridge), dislocation and expansion of the crimped cerebellar arteries, veins, basilar artery aneurysm, meningitis, adhesions after trauma, infections. Among extracranial factors, there are: the formation of a tunnel syndrome (compression of the second and third branches in the bony canals - the infraorbital and mandible with their congenital narrowness and adherence of vascular diseases in old age), local odonto- or rhinogenic inflammatory process.

The role of compression of the trigeminal nerve became more understandable when a "portal theory of pain" appeared. Compression violates the axon, leads to activation of autoimmune processes and causes focal demyelination. Under the influence of prolonged pathological impulses from the periphery in the spinal cord of the trigeminal nerve, a "focus", similar to the epileptic one, is the generator of pathologically enhanced excitation (GPOO), whose existence no longer depends on afferent impulses. The pulses from the trigger points arrive at the driving neurons of the generator and cause it to be lightly activated. The GPOO activates reticular, mesencephalic formations, thalamus nuclei, cerebral cortex, involves the limbic system, thus forming a pathological algogenic system.

The disease can develop after removal of the tooth (the lunar nerve is affected) - odontogenic neuralgia; as a result of circulatory disorders in the brainstem, herpetic infection; rarely due to demyelination of the spine of the trigeminal nerve with multiple sclerosis. Provoking factors may serve as an infection (influenza, malaria, syphilis, etc.), hypothermia, intoxications (lead, alcohol, nicotine), metabolic disorders (diabetes).

Other causes of pain in the face

Less often, but with a marked pain syndrome, there are neuralgia of individual zones of the trigeminal nerve - Charlene syndrome, Frey syndrome, lingual nerve. The defeat of the system of the facial, intervening nerves, glossopharyngeal and vagus nerves, vegetative ganglia of the face is accompanied by an equally pronounced facial pain with characteristic clinical features and also require urgent adequate therapy in the early stages.

Neuralgia of the naso-ciliary nerve (Charlene syndrome). It is accompanied by severe pain in the medial angle of the eye with irradiation in the back of the nose, sometimes orbital and near-orbital pain. The duration of the attack is from a few hours to a day. Pain in the face is  accompanied by lacrimation, photophobia, flushing of the sclera and nasal mucosa, edema, hyperesthesia on the affected side and one-sided hypersecretion of the nasal mucosa. Treatment: non-narcotic analgesics and NSAIDs; Bury in the eye and nose 0.25% solution of dicaine 1 -2 drops, to enhance the effect - 0.1% solution of adrenaline (3-5 drops per 10 ml of dicain).

Neuralgia of the auriculotemporal nerve (Frey syndrome). It is characterized by the appearance on the side of the lesion of paroxysmal pain in the depth of the ear, in the area of the anterior wall, external auditory canal and temple, especially in the temporomandibular joint area, often with irradiation into the lower jaw. It is accompanied by reddening of the skin, increased sweating in this area, salivation, change in pupil size on the side of the lesion. Attacks are provoked by the reception of a certain food and even when it is presented, as well as by external stimuli. Treatment: analgesics in combination with antihistamines, tranquilizers, neuroleptics; NSAIDs, vegetotrophic (belloid, bellaspon).

Neuralgia of the lingual nerve. Diagnosis is based on clinical data: the presence of bouts of burning pain in the face, the front 2/3 of the half of the tongue, which appear spontaneously or provoked by taking rough, spicy food, movements of the tongue, infections (tonsillitis, tonsillitis, influenza), intoxications, etc. On the corresponding half of the tongue, there are often disorders of sensitivity, more often as hyperesthesia, with prolonged flow, loss of pain and taste sensitivity. Treatment: analgesics - analgin, cigans, on the tongue - 1% solution of lidocaine, anticonvulsants, vitamins of group B.

Neuralgia of the facial nerve. In the picture of facial nerve neuropathy, the pain syndrome is manifested by shooting or aching pain in the region of the external auditory canal, with irradiation into the homolateral half of the head, migration in the region of the eyebrow, cheeks, inner corner of the eye, nose and chin wing, which increases with emotional stress in the cold and is facilitated under the influence of heat. Pain in the face is accompanied by asymmetry of the face along with a peculiar defect in mimicry, pathological synkinesia and hyperkinesia, development of paresis and secondary contracture of facial muscles, occurs after hypothermia, less often against the background of acute respiratory viral infection. Complex treatment includes "drug decompression" of the nerve in the facial canal (prescription of prednisolone, diuretics), vasoactive therapy (euphyllin, nicotinic acid), vitamins of B group, physiotherapy treatment, curative gymnastics, massage.

Neuralgia of the pharyngeal nerve. Paroxysmal pains in the face, always beginning with the root of the tongue or with the tonsils and extending to the palatal curtain, the pharynx radiating into the ear, sometimes into the eye, the angle of the lower jaw on the cheek. They are accompanied by hypersalivation, reddening of half of face, dry cough. Painful attacks last from 1 to 3 minutes. During an attack, dry cough, a taste disorder, a one-sided increase in sensitivity in the posterior third of the tongue, rarely a decrease in blood pressure and a loss of consciousness are noted. Usually, an attack is provoked by talking, eating, coughing, yawning.

Neuralgia of the superior laryngeal nerve (branch of the vagus nerve). It is characterized by one-sided pain in the face of a paroxysmal character in the larynx that radiates into the ear region and along the lower jaw, occurs during eating or swallowing. Sometimes laryngospasm develops during a bout of pain, a cough appears, a general weakness.

Syndrome of the wing-palatal node (Slader's syndrome). Attacks of acute pain in the eye, nose, upper jaw. Pain can extend to the area of the temple, ear, neck, neck, shoulder blade, shoulder, forearm, hand. Paroxysms are accompanied by pronounced vegetative symptoms: redness of half of face, swelling of facial tissues, lacrimation, abundant secretion from one half of the nose (vegetative storm). The duration of the attack from several minutes to days.

Myofascial facial syndrome. The main clinical manifestation is the combination of neuralgia of one of the cranial nerves (pain in the face, tongue, mouth, pharynx, larynx), motor disorders from the chewing muscles, a violation of taste, dysfunction of the temporomandibular joint. Pain in the face has no clear boundaries, the duration and intensity of it is different (from the state of discomfort to severe painful pain). Increases pain in the face of emotional tension, compression of the jaws, overload of chewing muscles, fatigue. The pain depends on the state of activity and localization of trigger points. There may be vegetative symptoms: sweating, vasospasm, runny nose, tear and salivation, dizziness, tinnitus, burning sensation in the tongue, etc.

Treatment of these syndromes is carried out together with a neurologist.

Pain in the face and trigeminal neuralgia

Neuralgia of the trigeminal nerve (synonyms: trigeminal neuralgia, painful tic, Fosergill disease) is a chronic disease that occurs with remissions and exacerbations, characterized by attacks of extremely intense, shooting pain in the zones of innervation of II, III or extremely rarely I branch of the trigeminal nerve.

Terminology

Traditionally, the primary (idiopathic) and secondary (symptomatic) trigeminal neuralgia are isolated. Symptomatic neuralgia develops as one of the manifestations of other CNS diseases (multiple sclerosis, glioma of the brainstem, tumors of the bridge and cerebellar region, stroke, etc.).

It is now established that the primary neuralgia of the trigeminal nerve in the vast majority of cases is associated with compression of the spine of the trigeminal nerve in the region of its entry into the brain stem. Usually, compression is caused by pathologically convoluted loop of the upper cerebellar artery (over 80% of cases). Therefore, if a neurosurgical operation was performed in the patient, during which the compression of the nerve root by a pathologically convoluted blood vessel was detected, secondary neuralgia should be diagnosed. However, the vast majority of patients do not undergo surgery. In such cases, although the compression etiology of trigeminal neuralgia is assumed, nevertheless, the term "primary" (classical, idiopathic) is used for its designation, and the term "secondary neuralgia of the trigeminal nerve" is used in patients with neuroimaging (or neurosurgical surgery) processes other than vascular compression (tumors, demyelination, etc.).

Pathogenesis

The mechanism of development of trigeminal neuralgia (as well as lumbosacral neuralgia) is explained in terms of the theory of "collateral pain control" by Melzak and Wall (1965). The theory of "collar pain control" suggests that fast-conducting (antinociceptive), well-myelinated type A fibers and non-myelinated (nociceptive) C fibers are in a competitive relationship, and normally the impulse flux over the fibers of proprioceptive sensitivity predominates. In neuralgias of V and IX pairs of cranial nerves due to compression of their roots when entering the brain stem, demyelination of fibers A occurs with the appearance on the demyelinated sites of a variety of additional voltage-dependent sodium channels, as well as the formation of contacts of these sections with fibers of type C. All this leads to the formation of prolonged and high-amplitude activity of pathologically altered fibers A, which is manifested by painful paroxysms in the area of the face and oral cavity.

Epidemiology

A typical trigeminal neuralgia makes its debut in the 5th decade of life. Women are more often ill (5 per 100 000 population, men - 2.7 per 100 000). Neuralgia of the trigeminal nerve often appears on the right (70%), on the left - (28%), in rare cases it can be bilateral (2%).

[1], [2], [3], [4], [5], [6]

Clinical picture and diagnosis

An unfolded attack of classical trigeminal neuralgia is characterized by a typical clinical picture and usually presents no difficulties for diagnosis. The most characteristic features of the pain syndrome.

• The pain of a paroxysmal, extremely cruel, shooting character in the face, compared by patients with discharges of electric current.
• The duration of pain paroxysm never exceeds 2 min (usually 10-15 s).
• Between 2 separate attacks there is a "light" gap (refractory period), the duration of which depends on the severity of the exacerbation.
• Pain in the period of exacerbation has a certain localization within the zones of innervation of the trigeminal nerve that has not changed significantly over many years of the disease.
• The pain attack always has a certain direction - the pain comes from one part of the face and reaches another.
• Presence of trigger (trigger) zones, that is, areas on the skin of the face and in the oral cavity, a weak irritation of which causes a typical paroxysm. The most common location of trigger zones is nasolabial triangle and alveolar process.
• The presence of triggers - actions or conditions, in which typical pain attacks occur. Most often such factors are washing, brushing teeth, chewing, talking.
• Typical behavior during an attack. As a rule, patients do not cry, do not cry, do not move, but freeze in the position in which they are seized by an attack. Sometimes patients rub up the area of pain or make smacking movements.
• At the height of a painful attack, there are sometimes twitchings of mimic or chewing muscles (at present, this symptom is rarely observed due to the use of anticonvulsants for the treatment of trigeminal neuralgia of the trigeminal nerve).
• Absence of sensory defect (loss of surface sensitivity) in the zone of painful attacks. This symptom is not necessary, since after a nerve-eye disease, retroasserial thermizoritomy or ethanol blockade, hypostasis remains in the nerve exit points on the face for a long time.

A number of patients develop a secondary muscular-fascial prozopalgic syndrome over time. All patients with neuralgia of the trigeminal nerve, both during the period of exacerbation and during remission, use a healthy half of the mouth to chew. Therefore, in the muscles of the homolateral sides of the face, degenerative changes occur with the development of typical muscular densities (the internal pterygoids and the posterior abdomen of the digastric muscle are the most vulnerable). With auscultation of the temporomandibular joint, sometimes a typical crunch is heard.

With the long-term course of the disease, it is possible to develop a neuralgic-neuritic stage (dystrophic), in which there is a moderate atrophy of the chewing muscles and a decrease in sensitivity on the affected half of the face.

Symptomatic neuralgia of the trigeminal nerve according to clinical manifestations does not differ from classical idiopathic neuralgia, the symptomatic nature of which can be indicated by the gradually increasing sensory deficit of the innervation zone of the corresponding branch, the absence of a refractory period after pain paroxysm at the onset of the disease, and the appearance of other focal symptoms of brainstem or adjacent cranial nerves (nystagmus, ataxia, hearing loss). One of the most frequent causes of symptomatic neuralgia of the trigeminal nerve is multiple sclerosis. Especially suspicious for multiple sclerosis is the occurrence of trigeminal neuralgia in a young patient, as well as changes in the side of neuralgia.

[7], [8], [9], [10], [11], [12]

Neuralgia of individual branches of the trigeminal nerve

Nasociliary neuralgia

Nasociliary neuralgia (Charlene's neuralgia) is relatively rare. It is manifested by stabbing pain with irradiation into the central region of the forehead when it touches the external surface of the nostrils.

Supraorbital neuralgia

The disease is observed as rarely as nasociliary neuralgia. It is characterized by paroxysmal or permanent pain in the region of the supraorbital incision and the medial part of the forehead, that is, in the zone of innervation of the supraorbital nerve. When palpation is determined soreness in the area of supraorbital tenderloin.

Neuralgia of other branches of the trigeminal nerve

Damage or compression of the branches of the trigeminal nerve can cause pain in the zone of their innervation.

• Neuralgia (neuropathy) of the infraorbital nerve is usually symptomatic and is caused by inflammatory processes in the maxillary sinus or nerve damage in complex dental manipulations. Pain is usually of minor intensity, a feeling of numbness in the mucosa of the upper jaw and the infraorbital region predominates.
• Causes of neuralgia of the lingual nerve may be prolonged irritation of the tongue with a prosthesis, a sharp edge of the tooth, etc. Moderate pain in half of the tongue is of a permanent nature and at times intensifies with eating, talking, and sharp facial movements.
• Neuralgia (neuropathy) of the lower alveolar nerve occurs with injuries and inflammatory diseases of the lower jaw, when the filling material leaves the top of the tooth, with the simultaneous removal of several teeth. It is characterized by a moderate permanent pain in the teeth of the lower jaw, in the region of the chin and lower lip. In some cases, neuropathy of the terminal branch of the lower alveolar nerve - the chin nerve - is observed. It manifests itself as hypostasis or paresthesia in the region of the chin and lower lip.
• Neuropathy of the buccal nerve is usually combined with neuropathy of the lower alveolar nerve. Pain syndrome is absent, typical hypoesthesia of the mucous membrane of the cheek, as well as the skin of the corresponding angle of the mouth.
• The term "tick-neuralgia" refers to the combination of periodic migraine neuralgia and neuralgia of the first branch of the trigeminal nerve.

Postherpetic neuralgia of the trigeminal nerve

Postherpetic neuralgia of the trigeminal nerve (postherpetic neuropathy of the trigeminal nerve) is a persistent or recurring facial pain for at least 3 months after the onset of Herpes zoster infection  . Postherpetic neuralgia of the trigeminal nerve is observed much more often than classical trigeminal neuralgia (2 per 1000, and in individuals older than 75 years - Yuna 1000 population). The defeat of the trigeminal nerve is noted in 15% of herpes zoster, and in 80% of cases the eye nerve is involved in the process (which is related to its minimal myelination as compared to the II and III branches of the V pair of cranial nerves). The appearance of the disease predisposes a decrease in immunity in the elderly, contributing to the activation of a persistently persistent virus in the body of  Varicella-zoster. The development of the disease passes through several stages: a prodromal, previous rash (acute pain, itching); unilateral rash (vesicles, pustules, crusts); skin healing (2-4 weeks); postherpetic neuralgia. For a neurologist, the diagnosis of the prodromal phase is important, when there are no rashes yet, but the pain syndrome has already appeared. To suspect herpes zoster allows revealing pink spots on the skin, in the zone of which there are itching, burning, pain. After 3-5 days, the erythematous background disappears and bubbles appear on the healthy skin. After the appearance of the rash, the diagnosis is not difficult. In the case of the development of postherpetic neuralgia of the trigeminal nerve, after the crusts fall off and the skin heals with the scarring elements, the leading complaint becomes permanent pain that occurs within 1 month in 15% of cases, and within a year - in 25%. Risk factors for postherpetic neuralgia include elderly age, female gender, the presence of severe pain in the prodromal stage and acute period, as well as the presence of severe skin rashes and subsequent scarring of the skin. Clinical manifestations in the advanced stage of postherpetic neuralgia are very typical.

• Scars on the skin (against the background of its hyper- and hypopigmentation) in the forehead and scalp.
• Presence of trigger areas on the scalp (symptom of the comb), forehead, eyelids.
• A combination of permanent and paroxysmal pain syndromes.
• The presence of allodynia, hypoesthesia, dysesthesia, hyperalgesia, hyperpathy.

Hunt's syndrome

In the herpetic infection, in addition to the trigeminal nerve, III, IV, and / or VI pairs of cranial nerves may also be affected, and in infectious lesions of the geniculate ganglion, the function of the facial and / or pre-collar nerve can be disrupted.

• Hunt-1 syndrome (the neuralgia of the knee joint, the syndrome of the knee joint,  Herpes zoster oticus, Zoster oticus), described by the American neurologist J. Hunt in 1907, is one of the forms of herpes zoster that occurs with the involvement of the knee joint . In an acute period, the rashes are localized in the external auditory canal, on the auricle, soft palate, palatine tonsils. The clinical picture of postherpetic neuralgia of the knee joint consists of one-sided permanent or periodic pain in the ear area, in the ipsilateral half of the face, external auditory canal, impaired taste in the anterior 2/3 of the tongue, moderate peripheral paresis of the facial muscles.
• Hunt-2 syndrome is caused by the defeat of sensory nodes of several cranial nerves - pre-vertebral, coxaeopharyngeal, vagus, and second and third cervical spinal nerves. Herpetic eruptions appear in the external auditory canal, the front 2/3 of the tongue, on the scalp. Pain in the back of the oral cavity radiates into the ear, back of the neck, and is accompanied by a salivation disorder, horizontal nystagmus, dizziness.

Tholos-Hunt Syndrome

The Tholos-Hunt syndrome arises suddenly and is characterized by periodic pain in the orbit, its edema, and also the defeat of one or several cranial nerves (III, IV and / or VI), usually passing independently. In some cases, the disease occurs with an alternation of remissions and exacerbations. In some patients, there is a violation of sympathetic innervation of the pupil.

The defeat of the cranial nerves coincides with the appearance of pain or occurs within 2 weeks after it. The cause of the Tolosa-Hunt syndrome is the proliferation of granulomatous tissue in the cavernous sinus, the upper orbital fissure or the orbit cavity. Painful ophthalmoplegia is also possible with neoplastic lesions in the area of the upper orbital gap.

Neuralgia of the glossopharyngeal nerve

The classical neuralgia of the glossopharyngeal nerve in clinical manifestations resembles neuralgia of the trigeminal nerve (which often becomes the cause of diagnostic errors), but it develops significantly less often than the latter (0.5 per 100 000 population).

The disease occurs in the form of painful paroxysms starting in the root of the tongue or tonsil and extending to the palatine curtain, pharynx, ear. Pain sometimes radiates into the corner of the lower jaw, eye, neck. Attacks, as a rule, are short-lived (1-3 min), are provoked by movements of the tongue, especially in loud conversations, with the intake of hot or cold food, irritation of the root of the tongue or amygdala (trigger zones). Pain is always one-sided. During the attack, patients complain of dryness in the throat, and after an attack hypersalivation appears. The amount of saliva on the side of pain is always reduced, even during the period of salivation (in comparison with the healthy side). Saliva on the side of pain is more viscous, its specific gravity is increased due to an increase in the mucus content.

In some cases, during an attack, the patients develop presyncopal or syncopal conditions (short-term faintness, dizziness, falling of arterial pressure, loss of consciousness). Probably, the development of these conditions is associated with irritation of the  n.  Depressor  (branch of the IX pair of cranial nerves), as a result of which the depression of the vasomotor center and the drop in arterial pressure occur.

In an objective examination of patients with neuralgia of the glossopharyngeal nerve, no changes are usually detected. Only in a small part of cases is noted the painfulness at palpation of the angle of the mandible and some parts of the external auditory canal (mainly during an attack), a decrease in the pharyngeal reflex, a decrease in the mobility of the soft palate, a perversion of taste sensitivity in the posterior third of the tongue (all taste irritations are perceived as bitter) .

The disease, like the trigeminal neuralgia, proceeds with exacerbations and remissions. After several attacks, remissions of different duration are noted, sometimes up to 1 year. Nevertheless, as a rule, seizures gradually increase, and the intensity of the pain syndrome increases. In the future, there may appear permanent pains that increase under the influence of various factors (for example, when swallowing). Symptoms of prolapse corresponding to the innervation of the glossopharyngeal nerve (neuritic stage of the glossopharyngeal nerve neurasthenia) - hypesthesia in the posterior third of the tongue, the tonsil region, the palatine curtain and the upper part of the pharynx, the violation of taste on the root of the tongue, the reduction of salivation (due to the parotid salivary gland ).

The classical neuralgia of the glossopharyngeal nerve, like the trigeminal neuralgia, is most often due to the compression of the nerve by the branch of the vessel in the region of the medulla oblongata.

The symptomatic neuralgia of the glossopharyngeal nerve differs from the classical one by the frequent presence of constant aching pain in the interstitial period, as well as progressive impairment of sensitivity in the innervating zone of the glossopharyngeal nerve. The most frequent causes of symptomatic neuralgia of the glossopharyngeal nerve are intracranial tumors, vascular malformations, volumetric processes in the region of the styloid process.

Neuralgia of the tympanic plexus

Neuralgia of the tympanic plexus (Reichert's syndrome) manifests itself as a symptom complex similar to that of the knee joint (although the tympanic nerve is a branch of the glossopharyngeal). This is a rare form of facial pain, the etiology and pathogenesis of which are still unclear. There are suggestions about the role of infection and vascular factors.

Typical acute shooting pains in the area of the external auditory canal, appearing paroxysmally and gradually subsiding. Pain occurs without apparent external causes. At the onset of the disease, the frequency of seizures does not exceed 5-6 times a day. The disease occurs with exacerbations, which last for several months, and then are replaced by remissions (lasting also several months).

In some patients, the development of the disease can be preceded by unpleasant sensations in the area of the external auditory canal, which sometimes spread to the entire face. When examining objective signs are usually not detected, only in some cases, note the soreness in palpation of the auditory canal.

Neuralgia of the nerve

Neuralgia of the intervening nerve is a rare disorder characterized by short paroxysms of pain in the depth of the ear passage. The main diagnostic criteria are periodic paroxysms of pain in the depth of the ear passage lasting from several seconds to several minutes, mainly on the back wall of the ear passage, where there is a trigger zone. Sometimes pain can be accompanied by violations of tear, salivation and / or taste disorders, often a connection with  Herpes zoster is found.

Neuralgia of the superior nerve of the larynx

Neuralgia of the upper nerve of the larynx is a fairly rare disorder, manifested by intense pain (paroxysms of pain lasting from several seconds to several minutes) in the region of the lateral wall of the pharynx, submandibular region and below the ear, provoked by swallowing movements, loud conversation or head turns. Trigger zone is located on the lateral wall of the pharynx above the membrane of the thyroid gland. With idiopathic form, pain is not associated with other causes.

Freya Syndrome

Frey's syndrome (neuropathy of the ear-temporal nerve, ear-temporal hyperhidrosis) is a rare disease, manifested by insignificant unstable pains in the parotid region, as well as hyperhidrosis and hyperemia of the skin in the parotid region when eating. Usually the cause of the disease is trauma or surgery in this area.

Musculoskeletal prozochrialygia

Skeletal-muscular prosocranialgia are most often associated with dysfunction of the temporomandibular joint and myofascial pain syndrome.

For the first time, the term "painful dysfunctional syndrome of the temporomandibular joint" was introduced by Schwartz (1955), describing its main manifestations - a violation of the coordination of masticatory muscles, a painful spasm of the chewing musculature, and restriction of the movements of the lower jaw. Subsequently, Laskin (1969) proposed another term - "myofascial painful dysfunctional face syndrome" with the identification of 4 main symptoms: pain in the face, soreness in the study of masticatory muscles, restriction of opening of the mouth, clicks when moving in the temporo-jaw joint. In the development of the syndrome, two periods are distinguished - the period of dysfunction and the period of painful spasm of the chewing musculature. At the same time, the beginning of this or that period depends on various factors affecting chewing muscles, of which psychoemotional disorders, leading to reflex spasm of the masticatory muscles, are considered the main ones. With muscle spasm, painful areas arise - trigger (trigger) zones, from which the pain irradiates into neighboring areas of the face and neck.

The characteristic diagnostic signs of myofascial pain syndrome are now considered to be the pain in the chewing muscles that increase with the movements of the lower jaw, the limitation of its mobility (opening the mouth to 15-25 mm between the incisors instead of 46-56 mm in norm), clicks and crepitation in the joint, S-shaped deflection of the lower jaw toward or forward when opening the mouth, pain during palpation of the muscles lifting the lower jaw. When palpation of the chewing musculature, painful seals are found (muscle trigger points). Stretching or squeezing these areas causes the appearance of pain that spreads to the neighboring areas of the face, head, neck (the so-called painful muscle pattern). The pain pattern corresponds not to neural innervation, but to a certain part of the sclerotome.

The development of myofascial pain dysfunctional syndrome is associated with prolonged stress of the masticatory muscles without their subsequent relaxation. First, a residual stress arises in the muscle, then in the intercellular space local seals are formed due to the transformation of the intercellular fluid into myogloidal nodules. These nodules also serve as a source of pathological impulses. The most common muscular trigger points are formed in the pterygoid muscles.

It was revealed that musculoskeletal prozopalgia often occurs in middle-aged people with asymmetric adentia, as well as with some behavioral habits (jaw clenching in stressful situations, support of the chin by the hand, extension of the lower jaw to the side or forward). X-ray changes in this case may be absent. In many cases, psychological causes (depression, hypochondria, neuroses) are of paramount importance in the formation of the disease.

Cervical-prosocarcinialgia

Cervical-lingual syndrome is manifested by pains in the occipital or upper cervical region that arise when the head turns sharply and accompanied by unpleasant sensations in the middle of the tongue (dysesthesia, numbness and pain).

Pain in the language is reflected and is caused by the pathology of the cervical spine, most often a subluxation of the atlanto-occipital articulation. The development of this syndrome is due to the fact that proprioceptive fibers from the tongue enter the spinal cord in the second dorsal cervical root and have connections with the lingual and sublingual nerves. This fact explains the appearance of unpleasant sensations in the language with compression of C ₂  (which is often observed with the subluxation of the atlantoaxial junction).

The syndrome of the styloid process is manifested by pains of mild or moderate intensity in the posterior part of the oral cavity that arise when swallowing, lowering the lower jaw, turning the head to the side, and palpating the projection of the area of the awl-hyoid ligament. The syndrome is caused by the calcification of the awl-hyoid ligament, but it can also develop with a neck or lower jaw injury. To protect themselves from the appearance of seizures, patients try to keep their head straight, with a slightly raised chin (hence one of the names of the disease - "eagle syndrome").

[13], [14]

Central pain in the face

The central facial pains include painful anesthesia  (anaesthesia  dolorosa)  and central pain after a stroke.

• Painful anesthesia of the face is manifested by burning, permanent pains, hyperpathy in the zone of innervation of the trigeminal nerve, which usually arise after the nervesector of the peripheral branches of the V pair of cranial nerves or the thermocoagulation of the semilunar node.
• Central facial pain after a stroke is most often combined with hemidizesthesia on the opposite side of the body.

[15], [16], [17]

Glossalgia

The incidence of the disease in the population is 0.7-2.6%, and in 85% of cases it develops in women in menopause. Often combined with the pathology of the gastrointestinal tract. Unpleasant sensations can be limited only to the front 2/3 of the tongue or spread to the front sections of the hard palate, the mucosa of the lower lip. Characteristic are the symptoms of the "mirror." (Daily examination of the tongue in the mirror to detect any changes), the "food dominant" (pain decreases or stops during eating), impaired salivation (usually xerostomia), taste changes (bitterness or metallic taste), psychological problems (irritability, fear, depression). The disease is characterized by a prolonged course.

Psychogenic pain in the face

Psychogenic facial pains in the practice of a neurologist are observed quite often, usually within the framework of a depressive syndrome or neuroses (hysteria).

• Hallucinogenic pain accompanies mental illnesses, such as schizophrenia, manic-depressive psychosis. They differ in the complexity and inaccessibility of understanding verbal characteristics and clearly pronounced sensopathic component ("snakes devour the brain", "worms move along the jaw", etc.).
• Hysterical facial pains are usually symmetrical, often combined with headaches, their intensity varies throughout the day. Patients describe them as "terrible, intolerable", but they have little effect on daily activity.
• Facial pains with depressions are more often bilateral, usually combined with headaches, often mark sensiopathies, expressed by simple verbal characteristics. Combine with the main symptoms of depression (motor retardation, bradyphrenia, mimic markers of depression, such as the lowered corners of the mouth, the crease of Werhaut, etc.).

Atypical pain in the face

Pain that does not fit into the description of neurogenic, vegetative, musculoskeletal skeletal muscle is attributed to atypical facial pains. As a rule, their atypicity is associated with the simultaneous presence of signs characteristic of several types of pain syndromes, but the psychopathological component is usually dominant.

One of the variants of atypical facial pain is a persistent idiopathic facial pain. Pain can be triggered by surgical intervention on the face, facial trauma, teeth or gums, but its permanence can not be explained by any local cause. The pain does not correspond to the diagnostic criteria of any of the described forms of cranial neuralgia and is not associated with any other pathology. Initially, pain occurs in a limited area on one side of the face, for example, in the area of the nasolabial fold or one side of the chin. In some cases, patients generally can not precisely localize their feelings. In the area of pain, no disorders of sensitivity or other organic disturbances are detected. Additional methods of investigation do not reveal any clinically significant pathology.

Another form of atypical facial pain is atypical odontalgia. This term is used to refer to prolonged pain in the teeth or bed after tooth extraction in the absence of any objective pathology. This syndrome is close to the so-called "dental plexalgia". Among the patients, menopausal women predominate (9: 1). Typical constant burning pains in the area of teeth and gums, often with repercussion on the opposite side. Objective signs of dental or neurological disorders are usually absent, although in some patients the syndrome develops after dental manipulations (simultaneous removal of several teeth or the emergence of the filling material behind the apex of the tooth). In some cases, there is a decrease in pain during food intake and enhancement - under the influence of emotions, unfavorable meteorological factors and hypothermia.

With the defeat of the upper dental plexus, the pain can irradiate along the course of the second branch of the trigeminal nerve and be accompanied by vegetative symptoms, which are probably due to the connections of the plexus to the autonomic ganglia (the winged node and the upper cervical sympathetic node). As a rule, there are no painful tendencies at the exit points of the branches of the trigeminal nerve and marked sensitivity disorders in the zones of innervation of its II and III branches.

Two-sided dental plexalgia develops almost exclusively in women after the age of 40, is characterized by a prolonged course. Burning pains usually appear on one side, but soon appear on the opposite side. Almost all patients have pain on both sides within 1 year. It is possible and simultaneous development of bilateral pain. As with unilateral dental plexalgia, the upper dental plexus is affected 2 times more often than the lower one.

To the possible etiological factors of bilateral dental plexalgia include complex removals of wisdom teeth, premolars and molars, conductive anesthesia, osteomyelitis of the holes, surgical interventions on the jaws, ingress of the filling material into the mandibular canal through the root canals of the teeth, removal of a large number of teeth for a short time during preparation of the oral cavity for prosthetics, infection, intoxication, trauma, etc.

[18], [19], [20]