Meningitis - inflammation of the membranes of the brain and spinal cord, usually of infectious origin. Meningitis is classified according to etiology (bacterial, viral, fungal, etc.), the nature of the inflammatory process (purulent, serous), course (acute, subacute, chronic), origin (primary and secondary, arising from another disease - otitis media, sinusitis , traumatic brain injury, etc.).
The clinical picture of meningitis is composed of intense diffuse headache , nausea , vomiting , confusion or depression of consciousness, including coma, fever , malaise, tachycardia , myalgia, and meningeal syndrome. Meningeal syndrome includes stiff neck that prevents passive bending of the head, Kernig symptom (inability to fully extend the leg in the knee joint, previously bent at right angles in the hip and knee joints), Brudzinski’s upper symptom (flexion of the thigh and lower leg when checking stiff neck) and Brudzinsky’s lower symptom (flexion of the thigh and lower leg when checking the Kernig symptom on the other leg), general hyperesthesia (intolerance to bright light, loud noises, touching the skin). Meningeal symptoms can often be detected even in a coma, but in the first hours of the disease, as well as in children and the elderly, they are sometimes absent. In elderly patients, meningitis can be manifested by a combination of fever with confusion or increasing depression of consciousness. On the other hand, stiff neck muscle in the elderly may not be due to meningitis, but to cervical osteochondrosis or parkinsonism. In contrast to these conditions, only neck flexion is difficult in meningitis, but not its rotation or extension. In young children, the symptom of hanging Lessage is determined (a child raised by the armpits presses his legs to his stomach and throws his head back). In infants, it is possible to identify the bulging of the large fontanel and the cessation of its pulsation caused by an increase in intracranial pressure. In addition to meningitis, meningeal symptoms ("meningism") can be detected with subarachnoid hemorrhage, intracranial hypertension, volume lesions of the posterior cranial fossa (hematoma or cerebellar abscess ), intoxication, head injury, malignant neuroleptic syndrome.
The development of meningitis is often preceded by an infection of the upper respiratory tract. Preliminary use of antibiotics often smooths the meningitis clinic. In immunocompromised patients, meningitis occurs either as a mild infection with a headache and moderate fever, or as a rapidly growing coma .
Crucial in the diagnosis of meningitis is the study of cerebrospinal fluid. The danger of lumbar puncture is associated with the possibility of wedging (see. Intracranial hypertension). In the absence of congestive optic nerve disks or other signs of a sharp increase in intracranial pressure or volumetric process, lumbar puncture is mandatory at the slightest suspicion of meningitis. The pressure of the cerebrospinal fluid with meningitis is usually increased. With purulent meningitis, the cerebrospinal fluid is cloudy, contains a large number of neutrophils, and the total number of cells (cytosis) exceeds 1000 in 1 μl. With serous meningitis, the cerebrospinal fluid is transparent and opalescent, it contains mainly lymphocytes, and cytosis usually amounts to several hundred cells in 1 μl. However, at an early stage with purulent meningitis, cytosis can be low, with a predominance of lymphocytes, while with serous meningitis in the cerebrospinal fluid (CSF) neutrophils can predominate, and only repeated puncture will avoid a diagnostic error in this case.
Purulent meningitis. The causative agents are usually bacteria (hemophilic bacillus, pneumococcus, meningococcus) that penetrate the central nervous system through the hematogenous route (with septicemia or metastasis from infectious foci in the heart, lungs) or by contact (with sinusitis, mastoiditis, osteomyelitis, traumatic brain injury, abscess ) Most cases of hemophilic bacillus meningitis occur in children under 6 years of age, but rarely occur at an older age, usually against the background of predisposing factors (sinusitis, pneumonia, otitis media, traumatic brain injury with cerebrospinal fluid, diabetes mellitus, alcoholism, splenectomy )
Meningococcal meningitis (see. Meningococcal infection). In severe cases of meningococcal meningitis occurring with meningococcemia, a characteristic hemorrhagic rash occurs. At first, the rash can be erythematous or spotty, but then it quickly transforms into a petechial. It often takes the form of stars of various sizes and shapes and is localized on the trunk and lower extremities (in the buttocks, thighs, legs). Petechiae can also be on the mucous membranes, conjunctiva, sometimes on the palms and soles. A similar rash can be observed with meningitis caused by enteroviruses, hemophilic bacillus, staphylococcus, listeria, pneumococcus, as well as bacterial endocarditis, rickettsiosis, vasculitis.
Pneumococcal meningitis is the most common variant of meningitis V chip older than 30 years. Pneumococcal meningitis often develops as a result of the spread of infection from distant foci. Pneumonia is detected in 25 - 50% of patients (pneumonia, otitis media, mastoiditis, sinusitis, endocarditis). The infection is especially severe in patients with reduced reactivity (with alcoholism, diabetes mellitus, after splenectomy, myeloma, with corticosteroid therapy, hemodialysis, cirrhosis). Pneumococcus often serves as the causative agent of post-traumatic meningitis in patients with fracture of the base of the skull and cerebrospinal fluid. Pneumococcal meningitis is difficult, often causes depression of consciousness and focal symptomatology (hemiparesis, paresis of the eye, damage to the cranial nerves), epileptic seizures, can recur and often result in death.
Relapse of bacterial meningitis is usually caused by an anatomical defect that violates the isolation of the subarachnoid space and is often a complication of traumatic brain injury (pneumococcus is often the causative agent in this case), or immunodeficiency. To detect cerebrospinal fluid fistula, a nasal discharge test is performed (high glucose is typical for CSF).
Focal neurological symptoms in meningitis are associated with the involvement of the cranial and spinal nerves, less commonly the brain substance itself. The oculomotor nerves are most often affected, but, as a rule, the movements of the eyeballs are restored within a few days or weeks. The defeat of the auditory nerve occurs less frequently, but more often is irreversible. Inflammation or thrombosis of the vessels at the base of the skull can lead to the development of a stroke. Increased intracranial pressure due to cerebral edema and hydrocephalus is accompanied by depression of consciousness, persistent vomiting, hiccups, epileptic seizures, oculomotor disorders, arterial hypertension and bradycardia.
Shock (usually occurring against the background of bacteremia or meningococcemia), blood clotting disorder (from mild thrombocytopenia to advanced DIC), endocarditis , suppurative arthritis , and adult respiratory distress syndrome can also complicate bacterial meningitis. Often complications are pneumonia , deep vein thrombosis of the lower leg, pulmonary thromboembolism , electrolyte disorders.
The diagnosis . At the slightest suspicion of purulent meningitis, lumbar puncture is indicated. If its implementation is not possible, a bacteriological examination of the blood, separated by skin rashes is carried out and antibiotic therapy is started. Bacterioscopic and bacteriological studies of cerebrospinal fluid are required to identify the pathogen and determine its sensitivity to antibiotics. The examination includes Gram stain, acid-resistant bacteria, and mascara staining (to detect cryptococci). In addition, during the study, it is necessary to find out whether there are foci of para-meningeal infection (for example, inflammation of the sinuses, middle ear, mastoiditis) or distant foci of infection (for example, pneumonia), as well as cerebrospinal fluid fistula.
Treatment . 1) After taking a sample of CSF and blood, antibiotics are immediately prescribed for bacteriological examination. To obtain the results of bacteriological studies, empirical antibacterial therapy is carried out. In newborns, a combination of cefotaxime and ampicillin (or ampicillin and gentamicin) is recommended, in children older than 2 months, third-generation cephalosporin (cefotaxime or ceftriaxoy) or a combination of ampicillin and chloramphenicol. In adults with normal immunity, the use of penicillin or ampicillin is indicated, however, taking into account the appearance of penicillin-resistant pneumococci and meningococci strains, III generation cephalosporins have been increasingly prescribed in recent years. For allergies to penicillin or cephalosporins, chloramphenicol is used. In the elderly, as well as in patients with reduced immunity, a combination of third-generation cephalosporin with ampicillin is advisable. If you are allergic to penicillins, trimethoprim-sulfamethoxazole (biseptol) is parenterally administered instead.
After obtaining the results of a bacteriological study of CSF, the antibiotic can be changed taking into account the sensitivity of the isolated strain and the clinical effect. All drugs should be administered intravenously, the doses are shown in the table. Intramuscular administration is allowed in mild cases.
Usually, significant improvement and normalization of temperature can be achieved within the first two days. After normalizing the temperature, antibiotic therapy should be continued for 10-14 days. With parameningeal infection, as well as with meningitis caused by gram-negative bacteria and listeria, the duration of treatment should be increased to 3-4 weeks. Before discontinuation of antibiotics, in order to verify the sanitation of CSF, a control puncture is performed. Antibiotics are canceled if CSF is sterile, contains less than 100 cells, of which lymphocytes make up at least 75%. If the fever persists despite antibacterial therapy for more than 2 - 5 days or reappears, then you should consider the possibility of complications, inadequate therapy, phlebitis, metastatic infection (septic arthritis, pericarditis, endocarditis, etc.) or the toxic effect of antibiotics. In the absence of effect, a second study of CSF should be done after 24-48 hours.