Bogorad syndrome is a pathology based on the development of which is the germination of the fibers of the facial or excretory nerves into the lacrimal and salivary glands. The main manifestations of the disease are increased lacrimation during meals, which can be combined with hypersalivation, photophobia, irritation of the skin of the face. MRI of the head, Schirmer’s test, electromyography, electroneurography, biomicroscopy of the eye are used for diagnosis. The treatment program includes blocking of parasympathetic innervation, facial nerve plasty and administration of vitamins of groups B, P, C.
G51.8 Other facial nerve lesions
Bogorad syndrome (crocodile tears disease, paroxysmal lacrimation syndrome) was first described in 1928 by the Belarusian neurologist F. A. Bogorad. The scientist compared lacrimation in this disease with the release of tears by a crocodile when devouring a victim. The prevalence of pathology in the general structure of ophthalmic diseases is 5:10,000 of the population. The ratio of the occurrence of the congenital form in relation to the acquired one is 1:5. The disease is observed in 6-30% of patients with facial neuralgia. In 30% of cases, the etiology of the disease cannot be established. Male and female individuals suffer with the same frequency. The disease is widespread everywhere.
The etiology of the disease is not fully understood. Cases are described when involuntary discharge of tears occurred after the defeat of the facial, less often – paresis of the abductor nerve. The main causes of Bogorad syndrome are:
- Taking medications. The congenital form of pathology develops in the case of the mother taking contraceptive drugs in the first trimester of pregnancy.
- Teratogenic effect. The occurrence of the disease in the neonatal period is often caused by the action of teratogenic factors during pregnancy, which include ultraviolet radiation, alcohol and drug use.
- Traumatic injury. Paroxysmal lacrimation occurs in patients after trauma with a violation of the integrity of the facial, upper salivary or excretory nerve.
- Iatrogenic effects. The cause of the disease may be intraoperative damage to nerve fibers. The clinical picture of the syndrome develops in the early, less often late postoperative period.
The appearance of symptoms in this pathology is preceded by a meal or strong odors. It has been proven that chewing movements without a specific stimulus or emotional lability do not cause symptoms. With facial nerve paralysis, lacrimation provokes the germination of the fibers of the drum string along the secretory nerve pathways of the lacrimal gland. The affected area is localized above the knee node. According to another pathogenetic theory, the development of the syndrome is caused by the germination of nerve fibers into the parenchyma of the lacrimal gland. Scientists believe that the basis of pathogenesis is the regeneration of nerve fibers after paralysis or traumatic injuries. In the congenital variant, pathological connections are formed in the nuclei of not only the facial, but also the diverting and upper salivary nerves. In neurology, the syndrome is considered as a “shower-lacrimal” reflex.
Regardless of the form of the syndrome, in most cases, symptoms occur on one side. Patients complain of increased lacrimation, which is often combined with excessive salivation. The development of symptoms provokes eating. Hard, hot and spicy foods cause more intense tear production. Less often, clinical manifestations are provoked by a strong smell. With a severe course of the syndrome, patients note the development of photophobia, irritation of the skin of the face. When the facial nerve is damaged, a violation of the functioning of the facial muscles on the side of the lesion is revealed, manifested by lowering the eyebrow, the corner of the mouth, smoothing the folds on the forehead, incomplete closing of the eye.
With a congenital form, the first signs of the disease are detected by parents even in the newborn period. Symptoms develop during the feeding of the baby. This leads to increased nervous excitability of the child, which is manifested by crying, irritability. Pathology is often combined with other anomalies (lagophthalmos, microphthalmos). If the disease is caused by paresis of the abductor nerve, in addition to increased lacrimation, hearing loss occurs, deformation of the auricles. In most patients, facial asymmetry is determined, which progresses with the growth of children. The disease significantly reduces the quality of life of patients.
Pathology can be complicated by a secondary inversion of the eyelid (ectropion). Due to increased tear production, there is a high probability of dacryocystitis. Patients are more at risk of developing bacterial bacterial keratitis, degenerative-dystrophic changes of the cornea. Severe course of the disease is accompanied by secondary conjunctivitis. In persons with a congenital form, a violation of the innervation of the upper eyelid leads to the appearance of lagophthalmos. Cases of hyperkeratosis caused by constant skin irritation are described. Less often, the pathological process spreads to the eyelids with the subsequent development of blepharitis.
Diagnosis of the syndrome usually does not cause difficulties. The diagnosis is based on anamnestic information, the results of visual examination and instrumental studies. The complex of special methods of examination includes:
- MRI of the head. Magnetic resonance imaging makes it possible to visualize the level and nature of damage to the abductor or facial nerve, to identify pathological synechiae. The study is used to determine further therapeutic tactics.
- Schirmer’s test. The sample allows you to determine the intensity of the production of tear fluid. Normal lacrimation in the absence of irritants and increased in response to food intake gives grounds to suspect paroxysmal lacrimation in the patient.
- Electromyography. The method is used to study information about the functional state of the pathways by evaluating the activity of individual muscle fibers that are innervated by them.
- Electroneurography. With this technique, it is possible to study the nature of damage to nerve fibers, the degree and localization of the affected area. The study is conducted in dynamics to assess the effectiveness of treatment.
- Biomicroscopy of the eye. The diagnostic procedure is used to identify secondary changes from the anterior part of the visual organ. With a prolonged course of pathology, hyperemia of the orbital conjunctiva, areas of corneal ulceration are visualized.
Differential diagnosis is carried out with increased tear production in dry eye syndrome. With xerophthalmia, the symptoms develop compensatorily due to the high dryness of the conjunctiva. Instillation of artificial tear preparations can eliminate clinical manifestations.
Patients are treated by a neurologist, but in all cases, an ophthalmologist and a neurosurgeon should be consulted. The management tactics of patients with Bogorad syndrome depends on the severity of clinical manifestations and the form of the disease. Etiotropic therapy has not been developed. The main methods of treatment include:
- Blocking of parasympathetic innervation. For therapeutic purposes, patients are injected with a small amount of botulinum toxin type A directly into the lacrimal gland. The technique allows to eliminate lacrimation under the action of the aroma or taste of food.
- Facial nerve plastic surgery. In Bogorad syndrome, removal of pathological branches of the facial nerve is indicated. Additionally, autotransplantation of nerve fibers is carried out in patients with a violation of their integrity in certain areas.
- Vitamin therapy. It is a mandatory part of complex therapy. Patients are shown taking vitamins of group C, B and R.
Treatment of the acquired form involves therapy of the underlying disease. In order to prevent the development of secondary complications, muscle relaxants, facial muscles massage are used. In the absence of an effect, the administration of drugs from the group of tranquilizers is indicated.
Prognosis and prevention
The prognosis for life and visual functions is favorable. In patients with an acquired form of pathology, the effectiveness of treatment is higher than in people with congenital syndrome. Specific preventive measures have not been developed. Non-specific prevention of the congenital variant is reduced to the exclusion of the effects of teratogenic factors and the use of contraceptives throughout the entire period of pregnancy. In adulthood, for preventive purposes, it is necessary to use personal protective equipment when working at work (helmets, masks, glasses), observe safety regulations.