Atypical facial pain is a chronic pain in the face that does not meet the criteria of other cranial neuralgias, is not associated with somatic pathologies. According to modern diagnostic criteria, atypical pain should be observed daily for at least two hours a day for three months or longer. The diagnostic program involves consultation with a psychiatrist and neurologist, dental examination, X-ray examination of the bones of the facial skull. Treatment includes psychotropic medications (antidepressants, anticonvulsants), cognitive behavioral psychotherapy, hardware methods of exposure.
G50.1 Atypical facial pain
The term “atypical facial pain” has existed since 1924, when it was proposed by doctors S. Fraser and I. Russell to describe atypical trigeminal neuralgia. Since 2001, the name has been replaced by the modern term “persistent idiopathic facial pain” (PIFP), which more accurately describes the nature of the pathology. The prevalence of facial pain in the general population is 17-26%, and in 6% of cases the malaise is caused by PIFP. Up to 60-70% of those suffering from atypical pain are middle-aged women.
Atypical facial pain is the least studied variant of prosopalgia (facial pain), since several mechanisms are involved in its development, and the psychogenic component is considered the main one. The disease is most often associated with depression, anxiety disorders, and other mental illnesses. To date, other predisposing and provoking factors of pathology have been established:
- Chronic stress. Psychoemotional tension triggers disturbances in the interaction of mediators, as a result of which the balance between the nociceptive and antinociceptive systems of the central nervous system disappears. Stress factors have a particularly negative effect on people with a passive coping strategy (a passive approach to countering stress).
- Surgical manipulations. Dental treatment, maxillofacial surgery, plastic surgery may be accompanied by damage to peripheral nerve fibers, which triggers a process of phantom soreness.
- Facial injuries. If PIFP was observed before the injury, then after the injury it usually worsens, and patients mistakenly consider an accident to be the main cause of the disease.
Tension of the masticatory muscles. In most patients, there is an asymmetry of muscle tension, a diffuse increase in muscle strength, excessive compression of the natural bite.
The mechanism of occurrence of atypical facial pain still remains undisclosed. It is assumed that the main role is played by disorders of neurotransmitter regulation in the central nervous system. At the same time, the sensitization of nociceptive fibers increases, the phenotype of afferent neurons changes, nerve cells are cross-activated, as a result of which signals can be transmitted without the participation of neurotransmitters.
An important mechanism of PIFP is considered to be springing — excessive growth of axons of afferent fibers in the direction of nociceptive neurons. Such synaptic springing enhances the flow of pain impulses entering the brain. In modern neurology, atypical morbidity is considered as psychogenic, in its appearance and development, great importance is given to the central mechanisms associated with depression.
Atypical pain and psychogenic factors are characterized by complex causal relationships. On the one hand, a long-term pain syndrome reduces the quality of life, provokes negative emotions, causes the formation of anxiety, depression. On the other hand, changes in the exchange of neurotransmitters in mental disorders can cause chronic painful sensations in the face.
The main complaint of patients is facial pain, which varies significantly in nature and intensity. Patients describe it as dull, aching, deep, exhausting. Some people describe the sensations as painful or unbearable, but most note the average intensity of the pain syndrome. Atypical pain in the face has a chronic course, increases under the influence of triggers, but does not have the character of attacks, unlike trigeminal neuralgia.
Atypical soreness becomes stronger under the influence of cold, stress, dental manipulations. Sometimes it migrates from one part of the face to another, in 40% of cases it appears bilaterally. Cases of discomfort spreading to the neck and shoulder girdle are described. Facial pain persists all day, periodically weakens or intensifies. At night, most of the patients do not have it. However, up to 70% of people suffering from PIFP are concerned about sleep disorders.
More than 65% of patients experience a feeling of numbness in the facial area, “crawling goosebumps”, hot flashes, and other unpleasant non-painful sensations. Often there is a subjective feeling of puffiness or asymmetry of the face, although an objective examination does not detect this. A characteristic feature of atypical pain is the absence of sensory disturbances when assessing the neurological status of the patient.
Chronic pain syndromes in most cases have several localizations. In addition to atypical prosopalgia, patients are concerned about back and lower back pain, unexplained myalgia, migraines. Many women face moderate or severe premenstrual syndrome, dysmenorrhea. Somatoform disorders are represented by irritable bowel syndrome, neurodermatitis, hyperventilation syndrome.
Psychiatric diseases are more common among patients with idiopathic facial pain than in the population. 16% of people are diagnosed with affective disorders, 15% — signs of somatoform disorders, 5% — psychosis. Hypochondria develops against the background of atypical prosopalgia, which is why people turn to many specialists, recognize themselves as seriously ill, and require various, often unnecessary treatment from doctors.
Patients with atypical facial soreness demonstrate a subjective decrease in the quality of life. In the standardized assessment, the physical and mental components of health averaged 47 and 35 points, respectively, while in the control group the values were an order of magnitude higher — 75 and 68 points. Constant dissatisfaction with one’s own well-being results in problems in family relationships, a decrease in working capacity.
Taking into account the polymorphism of symptoms, diagnosis is difficult. Before atypical facial pain is detected, patients are diagnosed and treated by at least 3-6 specialists. When examining patients, up to 48% of doctors practice the “diagnosis-exclusion” approach, 22% use the official criteria of the International Classification of Headache (3rd revision), the rest of the specialists combine both methods. The following research methods are used to diagnose PIFP:
- Neurological examination. Atypical type of pain is localized in any areas of the face, regardless of the areas of innervation of the trigeminal nerve. Often the pain is felt in the mouth area. In the study of sensitivity, deviations are not detected, although patients complain of various sensory disorders. There are no trigger points on the face.
- Dental examination. To exclude the odontogenic nature of soreness, a standard examination is recommended. If affected teeth are found, their treatment is necessary, after which in some cases prosopalgia disappears. However, true PIFP has a persistent character, continues to bother the patient even after thorough sanitation of the oral cavity.
- Radiography of the bones of the facial skeleton. The study is necessary if damage to the temporomandibular joint is suspected. Additionally, an orthopantomogram, CT of the skull bones is prescribed. The presence of volumetric neoplasms, other organic lesions of the central nervous system is excluded during brain MRI.
- Consultation of a psychiatrist. Since atypical facial pain often has a psychogenic cause, a full examination is mandatory. During the conversation and testing, it is possible to establish the mental status of the patient, to identify both the prerequisites and complications of a long-existing PIFP.
In practice, the criteria of the beta version of the International Classification of Disorders Accompanied by Headache (ICGB-3) are applied. According to them, PIFP worries daily for at least 2 hours for 3 months or more, is poorly localized, does not spread along the nerves. The criteria of ICGB-3 include normal neurological status, absence of dental diseases and grounds for an alternative diagnosis.
Clear principles of therapy for atypical facial pain have not yet been developed. The generally accepted tactic is to minimize unjustified dental and surgical manipulations, even if the patient insists on carrying out such. This is necessary to exclude the typical traumatic triggers of pain syndrome. The medical treatment of the disease is empirical. The following groups of drugs are used:
- Antidepressants. Tricyclic antidepressants have the best effect, which normalize the level of neurotransmitters in the brain, stimulate the antinociceptive system of the central nervous system.
- Anticonvulsants. Benzodiazepines and GABA analogues are shown, which have an additional analgesic effect. The combination of anticonvulsant medications with antidepressants shows good effectiveness.
- Botulinum toxin. With severe facial soreness, it is possible to achieve a temporary analgesic effect by injecting botulinum toxin type A into the gums, palate, upper lip.
- Antibodies to the S100 protein. The innovative drug normalizes the processes of transmission of impulses between neurons, reduces the level of anxiety, increases the resistance of the nervous system to stress.
To enhance the effect of the drugs, non-drug treatment is prescribed: low-energy diode laser, transcranial magnetic stimulation, biofeedback, pulse radiofrequency therapy. Cognitive behavioral, rational psychotherapy is recommended to reduce anxiety, to help the patient overcome pain. In resistant cases, hypnotherapy can be used.
Prognosis and prevention
Atypical facial pain is a difficult-to-treat disease due to the lack of clinical recommendations, ambiguity of etiopathogenetic features. The treatment reduces the intensity of pain, however, as a rule, atypical discomfort persists or disappears for a short time and reappears under the influence of provoking factors. Taking into account the psychogenic prerequisites of pathology, the basis of prevention is mental health care.