Meningitis is an 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), the course (acute, subacute, chronic), origin (primary and secondary, occurring against the background of another disease - otitis, sinusitis , traumatic brain injury, etc.).
The clinical picture of meningitis is an intense diffuse headache , nausea , vomiting , confusion or depression of consciousness, even coma, fever , malaise, tachycardia , myalgia and meningeal syndrome. Meningeal syndrome includes stiff neck, which prevents passive flexion of the head, Kernig's symptom (the inability to fully flex the knee joint leg, previously bent at right angles to the hip and knee joints), the upper Brudzinsky symptom (hip and lower leg flexion when checking the rigidity of the neck muscles of the neck muscles, checking the rigidity of the neck muscles of the neck muscles, flexing the hip and lower leg when checking the rigidity of the neck muscles and knees). lower Brudzinsky symptom (flexion of the hip and lower leg when checking Kernig's symptom on the other leg), general hyperesthesia (intolerance of bright light, loud sounds, touching the skin). Meningeal symptoms can often be detected even in a coma, but they are sometimes absent in the early hours of the disease, as well as in children and the elderly. In elderly patients, meningitis may be manifested by a combination of fever with confusion or increasing depression of consciousness. On the other hand, rigidity of the neck muscles in the elderly may be the result not of meningitis, but of cervical osteochondrosis or parkinsonism. In contrast to these conditions, meningitis is complicated only by flexing the neck, but not its rotation or extension. In young children determine the symptom of suspension of the Lessage (raised armpit, the child presses his legs to his stomach and throws back his head). In infants, it is possible to detect the bulging of a 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 abscess of the cerebellum), intoxication, craniocerebral trauma, and malignant neuroleptic syndrome.
The development of meningitis is often preceded by an infection of the upper respiratory tract. Prior antibiotic use often smoothes 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 importance in the diagnosis of meningitis is the study of liquor. The danger of lumbar puncture is associated with the possibility of a wedge (see Intracranial hypertension). In the absence of stagnant disks of the optic nerves or other signs of a sharp increase in intracranial pressure or volume process, lumbar puncture is required at the slightest suspicion of meningitis. Liver pressure in meningitis is usually elevated. In purulent meningitis, the CSF is cloudy, contains a large number of neutrophils, and the total number of cells (cytosis) exceeds 1000 in 1 μl. With serous meningitis, CSF is transparent and opalescent, contains mostly lymphocytes, and cytosis is usually several hundred cells per 1 μl. However, at an early stage, with purulent meningitis, cytosis can be low, with a predominance of lymphocytes, whereas with serous meningitis in the cerebrospinal fluid (CSF), neutrophils may prevail, and only in this case will the diagnostic error be avoided.
Purulent meningitis. Activators usually serve bacteria (Haemophilus influenzae, pneumococcus, meningococcus) that penetrate the CNS hematogenous route (for septicemia or metastasis of infectious foci in the heart, the lungs) or by contact (for sinusitis, mastoiditis, osteomyelitis, traumatic brain injury, brain abscess ). Most cases of meningitis caused by Hemophilus bacillus occur in children under 6 years of age, but occasionally occur in older age, usually against the background of predisposing factors (sinusitis, pneumonia, otitis media, brain injury, diabetes mellitus, alcoholism, splenectomy ).
Meningococcal meningitis (see Meningococcal infection). In severe cases of meningococcal meningitis, occurring with meningococcemia, a characteristic hemorrhagic rash occurs. Initially, the rash may be erythematous or spotted, but then it quickly transforms into a petechial rash. It often looks like asterisks of various sizes and shapes and is localized on the body and lower extremities (in the area of the buttocks, thighs, and legs). Petechiae can also be on the mucous membranes, conjunctiva, sometimes on the palms and soles. A similar rash can be observed in meningitis caused by enteroviruses, hemophilus bacilli, staphylococcus, listeria, pneumococcus, as well as with bacterial endocarditis, rickettsiosis, and vasculitis.
Pneumococcal meningitis is the most common variant of meningitis V chip over 30 years old. 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). Especially severe infection occurs in patients with reduced reactivity (in alcoholism, diabetes, after splenectomy, multiple myeloma, with corticosteroid therapy, hemodialysis, cirrhosis of the liver). Pneumococcus is often the causative agent of post-traumatic meningitis in patients with a fracture of the skull base and liquorrhea. Pneumococcal meningitis is severe, often causes depression of consciousness and focal symmatics (hemiparesis, paresis of the eye, lesion of cranial nerves), epileptic seizures, can recur, and often ends in death.
Recurrence of bacterial meningitis is usually caused by an anatomical defect that breaks the isolation of the subarachnoid space and is often a complication of traumatic brain injury (the causative agent in this case often serves as pneumococcus), or immunodeficiency. For detection of cerebrospinal fluid fistula, a study of discharge from the nose (high glucose content is characteristic of CSF).
Focal neurological symptoms in meningitis are associated with the involvement of the cranial and spinal nerves, less often - the very substance of the brain. Especially often the oculomotor nerves are 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 on the base of the skull can lead to the development of a stroke. The increase in ICP due to cerebral edema and hydrocephalus is accompanied by depression of consciousness, persistent vomiting, hiccups, epileptic seizures, oculomotor disorders, arterial hypertension and bradycardia.
Complications of bacterial meningitis can also include shock (usually occurring on the background of bacteremia or meningococcemia), bleeding disorders (from mild thrombocytopenia to expanded DIC), endocarditis , purulent arthritis , and respiratory distress syndrome in adults. Often the complications are pneumonia , deep vein thrombosis of the lower leg, pulmonary thromboembolism , electrolyte disorders.
The diagnosis . At the slightest suspicion of purulent meningitis, a lumbar puncture is indicated. If it is not possible to conduct it, conduct a bacteriological examination of the blood, discharge of skin rashes, and initiate antibiotic therapy. Bacterioscopic and bacteriological studies of cerebrospinal fluid are necessary in order to identify the pathogen and determine its sensitivity to antibiotics. The examination includes Gram stain, a study on acid-resistant bacteria, and ink for mascara (to detect cryptococci). In addition, during the study, it is necessary to find out whether there are foci of parameningeal infection (for example, inflammation of the paranasal sinuses, middle ear, mastoiditis) or distant foci of infection (for example, pneumonia), as well as the cerebrospinal fluid fistula.
Treatment . 1) After taking a sample of CSF and blood, antibiotics are immediately prescribed for bacteriological examination. Prior to obtaining the results of bacteriological research, empirical antibiotic therapy is carried out. In newborns, a combination of cefotaxime and ampicillin (or ampicillin and gentamicin) is recommended, in children over 2 months old - third generation cephalosporin (cefotaxime or ceftriaxo) or a combination of ampicillin and levomycetin. In adults with normal immunity, penicillin or ampicillin is indicated, however, taking into account the appearance of penicillin-resistant strains of pneumococci and meningococci, III generation cephalosporins have been increasingly prescribed in recent years. If you are allergic to penicillin or cephalosporins, levomycetin 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, in this case, trimethoprim-sulfamethoxazole (Biseptol) is administered parenterally instead.
After obtaining the results of bacteriological examination of the 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 injection is allowed in mild cases.
Usually a significant improvement and normalization of temperature can be achieved within the first two days. After the temperature is normalized, antibiotic therapy should be continued for 10–14 days. In cases of parameningeal infections, as well as meningitis caused by Gram-negative bacteria and Listeria, the duration of treatment should be increased to 3-4 weeks. Before the abolition of antibiotics, to ensure the rehabilitation of CSF, conduct a control puncture. Antibiotics cancel, if CSF is sterile, contains less than 100 cells, of which lymphocytes are at least 75%. If the fever persists despite antibiotic 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, repeated CSF testing should be performed in 24–48 hours.