Neurobrucellosis is a pathology of the nervous system that occurs against the background of brucellosis infection. The clinical picture is polymorphic, depending on the localization of the pathological process, it is represented by neuritis, radiculitis, meningitis, encephalitis, myelitis. Neurobrucellosis is diagnosed on the basis of an epidemiological history, neurological examination, bacteriological, serological studies, analysis of cerebrospinal fluid, neuroimaging, ENMG. Treatment includes antibiotic therapy, symptomatic agents (diuretics, steroids, vascular, anticholinesterase, psychotropic drugs), physiotherapy.
General information
Brucellosis is a zoonotic infectious disease that is relevant for livestock regions. In 80% of cases, the acute form of infection takes a chronic course due to intracellular persistence of brucella. Neurobrucellosis occurs in 3-5% of patients with brucellosis, often develops against the background of a chronic form of the disease, sometimes it is the first clinical manifestation. Mainly the peripheral and autonomic nervous system (NS) are affected. Neurobrucellosis is common in areas where livestock farms are located. The peak incidence falls on the most able—bodied age – 25-45 years.
Causes
The pathological process in the nervous system is part of a generalized infectious lesion of the body with brucella. The latter are gram-positive bacteria resistant in the environment. The reservoir of brucella are domestic animals: sheep, cattle, goats, pigs. The penetration of pathogens into the human body occurs in the following ways:
- Alimentary. Water and food products can be contaminated with brucelles. Milk, fermented milk products from unpasteurized raw materials (cheese, kefir, cream), thermally poorly processed meat are particularly dangerous. Getting brucella into food is possible from contaminated hands, clothes.
- Contact. When caring for animals, processing raw materials, bacteria can penetrate through microcracks, wounds on the skin. Getting into the blood, they spread throughout the body. The contact mechanism of infection is implemented much less often than alimentary.
- Air-dust. Brucella is carried through the air by dust particles, which are particles of earth, wool, animal feces. Human infection occurs when inhaling air containing dust particles seeded with brucella.
The brucella that have penetrated the body are attacked by protective immune agents and can be destroyed. The development of the infectious process occurs when infected with a large number of bacteria, reduced immunity, hypovitaminosis, weakened condition due to frequent acute respiratory infections, chronic diseases, fatigue.
Pathogenesis
Neurobrucellosis occurs due to hematogenic, lymphogenic introduction of pathogens into nerve tissues. Due to the anti-lysozyme activity, brucella is able to persist in nerve cells for a long time. The perineural spread of bacteria causes a gradual progression of the lesion. The infectious process is accompanied by sensitization, which triggers autoimmune mechanisms. In the acute period, serous infectious autoimmune inflammation dominates in the affected nerve trunks and tissues of the central nervous system. Involvement in the inflammatory process of blood vessels with the development of vasculitis causes a hemorrhagic component — petechial hemorrhages due to increased permeability of the vascular wall. In the chronic phase, degenerative changes prevail. Microscopically, pathology of the cytoplasm of neurons (vacuolization, tigrolysis), swelling and fragmentation of nerve fibers are noted.
Classification
Neurobrucellosis has no generally accepted classification. American specialists in the field of neurology prefer to use clinical and topographic separation of various forms of the disease. According to this approach, there are 4 main variants of neurobrucellosis.
- Lesions of peripheral NS. The most typical variant of the disease. Includes neuritis, polyneuropathy, plexitis, radiculitis. The first place in frequency of occurrence is occupied by sciatic nerve neuritis, lumbosacral plexitis.
- Brucellosis lesions of the central nervous system. The following clinical forms are possible: meningitis, encephalitis, meningoencephalitis, myelitis, encephalomyelitis. Neurobrucellosis of the central nervous system occurs in 1.6% of cases of brucellosis infection.
- Vascular lesions of the central nervous system. Occur as a result of cerebral vasculitis. These include subarachnoid hemorrhages, vasomotor disorders (PNMC, TIA), ischemic strokes, parenchymal hemorrhages.
- Lesions of vegetative NS. They are observed in 90% of patients. Hyperhidrosis, dry skin, vegetative pain, vegetative-vascular dystonia, disorders of the secretory and motor functions of the gastrointestinal tract are possible.
Symptoms
The incubation period lasts 1-4 weeks. There may be a primary latent course of infection lasting several months, which may be accompanied by vegetative disorders. In the acute septic period, neurobrucellosis occurs in the form of meningitis, vascular lesions. Brucellosis meningitis is manifested by meningeal syndrome, the appearance of trigger points on the head, neck. In some cases, meningitis has a latent course, it is diagnosed only by analyzing the cerebrospinal fluid. Vasomotor brain disorders are characterized by the transient nature of focal symptoms (paresis, speech disorders, visual function). Subarachnoid hemorrhage occurs with intense headache, shell symptoms, dysfunction of cranial nerves. Strokes are characterized by a typical clinical picture.
Neurobrucellosis with peripheral nerve damage debuts after a decrease in fever in the acute phase of infection or at the stage of chronic course. Mono- and polyneuritis, neuralgia, plexitis, radicular syndromes are noted, more often with inflammation of the sciatic nerve, plexuses and roots of lumbar localization. A distinctive feature of brucellosis lumbar plexitis and sciatica is a diffuse pain syndrome covering the entire gluteal region. Polyneuritis can be asymmetric, not necessarily spread to all limbs, accompanied by vegetative symptoms: cold, cyanosis, sweating, swelling of the distal extremities.
Neurobrucellosis can occur with damage to the cranial nerves. Most often, inflammation affects the optic and vestibular-cochlear nerves. In the first case, there is a decrease in visual acuity, a feeling of “fog in front of the eyes”, in the second — hearing loss. Hearing loss is bilateral in nature, may be the only symptom of neurobrucellosis after an acute period of infection.
Brucellosis inflammation of cerebral tissues (encephalitis) is characterized by polymorphic symptoms. There are spastic paresis, conduction disorders of sensitivity, cerebellar syndrome, vestibular ataxia, speech disorders. Myoclonia, extrapyramidal disorders (choreic hyperkinesis, parkinsonism), mental disorders (psychomotor agitation, hallucinatory syndrome, euphoric states, delirium) occur less frequently.
Neurobrucellosis in the form of myelitis is characterized by motor disorders, moderate severity of sensory and pelvic disorders. Transverse myelitis of thoracic localization with lower central paraparesis is more common. There may be a combined lesion of the spinal cord and optic nerve — brucellosis opticomyelitis.
Complications
In the absence of timely treatment, inflammatory changes in nerve trunks lead to irreversible impairment of the function of the affected nerve: the development of paresis, persistent visual and hearing disorders. The most severe residual phenomena (paresis, paralysis, joint contractures) accompany cerebral and spinal neurobrucellosis. A formidable complication is cerebral edema, which develops as a result of diffuse inflammatory changes in cerebral tissues, intracranial hemorrhage, and extensive ischemic stroke. The displacement of brain structures that occurs as a result of pronounced edema is dangerous by infringement of the medulla oblongata with suppression of the vital centers localized in it.
Diagnostics
An important diagnostic point is the collection of anamnestic data: epidemiological (professional activity, place of residence, contact with animals), clinical (previous wave fever, arthralgia, myalgia, lymphadenopathy, hepatosplenomegaly). The examination of the patient includes consultations with related specialists: an infectious disease specialist, a neurologist, an ophthalmologist, a rheumatologist. The list of diagnostic studies includes:
- Clinical tests: general blood and urine analysis, biochemical blood test. To exclude rheumatism, the level of rheumatoid factor, C-reactive protein, is determined.
- Bacteriological diagnostics. In order to identify an infectious agent, blood, cerebrospinal fluid, lymph node punctate (with adenopathy), synovial fluid (with arthritis) are pumped.
- Serological studies. Express diagnostics is carried out using the agglutination reaction on the Heddelson glass. Wright’s agglutination reaction is more reliable. Both tests give a positive result in previously ill people vaccinated against brucellosis patients.
- The Burne test. A specific skin allergy test with brucellin is positive by the end of the first month of the disease in 70-85% of patients.
- Examination of cerebrospinal fluid. Neurobrucellosis with CNS damage is accompanied by an increase in protein concentration, lymphocytic pleocytosis. The transparency of the cerebrospinal fluid indicates the serous nature of inflammation, the presence of blood indicates subarachnoid hemorrhage.
- Methods of neuroimaging. CT, MRI, MSCT of the brain reveal diffuse nonspecific changes in the white matter. They allow to diagnose stroke, intracranial hemorrhages, exclude focal pathology of the brain (tumor, cyst).
- Electromyoneirography. It reveals a decrease in the conductive ability of the affected nerves. Helps to establish the nature and level of peripheral NS lesion.
Neurobrucellosis should be differentiated with a number of diseases. Differential diagnosis is carried out with neurorheumatism, neurosyphilis, tularemia, encephalitis, meningitis, myelitis of viral etiology. Brucellosis lesions of nerves, spinal roots and plexuses must be distinguished from vertebrogenic syndromes, nerve tumors, dysmetabolic complications (for example, diabetic neuropathy).
Treatment
Therapy is aimed at eliminating the pathogen, preventing complications, restoring lost nerve functions. Neurobrucellosis of the acute and subacute phases requires inpatient treatment with follow-up treatment on an outpatient basis. Treatment is carried out for a long time (for several months), includes the following components:
- Antibacterial therapy. It is carried out by a combination of two antibiotics, a combination of rifampicin with gentamicin, doxycycline is widely used. With meningitis, encephalitis, parenteral administration of drugs is carried out, followed by a transition to oral administration. The chronic form is an indication for the introduction of an anti-brucellosis vaccine.
- Symptomatic treatment. Prevention of brain edema is carried out by diuretics, osmodiuretics. In severe cases, glucocorticosteroids are prescribed. Anticholinesterase pharmaceuticals (neostigmine) contribute to the restoration of the motor sphere. Vascular disorders are corrected by vasoactive, antiplatelet agents; mental abnormalities are corrected by psychotropic drugs.
- Physical therapy. It is effective in the treatment of peripheral NS pathology. UHF, electrophoresis, paraffin therapy, mud therapy are used. In the rehabilitation period, massage, physical therapy, reflexotherapy are used to restore the volume of movements.
Prognosis and prevention
The outcome of the disease depends on its form. With encephalitis, cerebral vascular pathology, the prognosis is serious. Timely etiotropic therapy contributes to the recovery of most patients. In some cases, neurobrucellosis survivors have persistent residual effects: visual disorders, hearing loss, paresis, etc. Persistence of brucella causes the possibility of relapses. Preventive measures are identical to the prevention of brucellosis, include: veterinary control, regular inspections of livestock breeders, control of food products. Specific prophylaxis is carried out with a brucellosis vaccine, which is administered to animals as planned. People are vaccinated against brucellosis according to epidemic indications.