Subacute and chronic meningitis: causes, symptoms, diagnosis, treatment

Inflammation of the meninges lasting more than 2 weeks (subacute meningitis) or more than 1 month (chronic meningitis) of an infectious or non-infectious nature (for example, with cancer).

The diagnosis is based on the results of the CSF study, usually after a preliminary CT scan or MRI. Treatment is aimed at the root cause of the disease.

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What causes subacute and chronic meningitis?

Subacute or chronic meningitis may be infectious or non-infectious in nature and may be aseptic meningitis. Among infectious causes, fungal infections are most likely (primarily Cryptococcus neoformans), tuberculosis, Lyme disease, AIDS, actinomycetosis and syphilis; noninfectious causes of subacute or chronic meningitis include a variety of diseases, including sarcoidosis, vasculitis, Behcet's disease, malignant tumors such as lymphomas, leukemias, melanomas, certain carcinomas and gliomas (in particular, glioblastoma, ependymoma and medulloblastoma). Non-infectious causes also include chemical reactions to the endolumbal administration of certain drugs.

The widespread use of immunosuppressants and the AIDS epidemic have led to an increase in the incidence of fungal meningitis. Representatives of Cryptococcus spp., While representatives of the genera Coccidioides, Candida, Actinomyces, Histoplasma and Aspergillus are most likely to be the most likely pathogens in AIDS patients, Hodgkin's lymphoma or lymphosarcoma, as well as in individuals receiving long doses of glucocorticoids .

Symptoms of subacute and chronic meningitis

In most cases, the clinical manifestations are the same as in acute meningitis, but the course of the disease is slower with the gradual development of symptoms within a few weeks. Fever can be minimal, with almost always present headache, back pain, symptoms of cranial nerves and peripheral nerves. Complication in the form of a communicating hydrocephalus is fraught with the development of dementia. Increased intracranial pressure induces a persistent headache, vomiting and decreases the ability to work in the range of several days to several weeks. Without treatment, it is possible as a lethal outcome in a few weeks or months (for example, with tuberculosis or a tumor), and the chronicization of symptoms for many years (for example, with Lyme disease).

Diagnosis and treatment of subacute and chronic meningitis

The presence of acute or chronic meningitis in a patient should be suspected for a prolonged (> 2 weeks) development of symptoms, including meningeal, as well as focal neurological symptoms (not necessarily), especially if the patient has a disease that can be a potential cause of meningitis (for example, active form of tuberculosis, cancer). To confirm the diagnosis, examine CSF. CT or MRI is necessary to exclude the volume formation responsible for focal neurological symptoms (ie, tumors, abscess, subdural effusions) and to confirm the safety of the lumbar puncture. CSF pressure is often increased, but may be normal, pleocytosis characterized by a predominance of lymphocytes, glucose concentration is slightly reduced, the level of protein is high.

The need for an additional study of CSF (specific staining, planting on selective culture media for fungal cultures and acid-fast bacilli) is determined on the basis of clinical and anamnestic data and available risk factors. In particular, people who abuse alcohol, HIV-infected or from endemic regions have a reason to suspect tuberculosis. For bacterioscopic identification of the pathogen, special staining for acid resistance or use of immunofluorescent dyes is required, as well as more laborious and thorough bacterioscopy of 30-50 ml of CSF, which requires 3-5 lumbar punctures. The gold standard of diagnosis is the production of a culture with subsequent identification, which requires an additional 30-50 ml of CSF, as well as 2 to 6 weeks of time. One of the specific methods for diagnosing tuberculosis infection is the detection of tubulostearic acid in CSF by gas-liquid chromatography, but due to its technical complexity, this method has limited application. PCR is the most promising method for rapid diagnosis of tuberculosis, but it can give a false positive or false-negative result, in part because of differences in standards in laboratories.

Bacterioscopic diagnosis of Cryptococcus fungi is carried out in a wet preparation or after staining with mascara. In the CSF crops, Cryptococcus and Candida cultures grow for several days, cultures of other less common pathogens of fungal infections grow for several weeks. A highly sensitive and specific method for the diagnosis of cryptococcal infection is the definition of cryptococcal antigen in CSF. To detect non-pyrolysis, a non-treponemal reaction is performed with CSF (VDRL test - research laboratories of venereal diseases). The detection of antibodies to Borrelia burgdorferi in cerebrospinal fluid confirms the diagnosis of Lyme disease.

For the verification of neoplastic meningitis, tumor cells should be found in the CSF. The probability of detection depends on the amount of CSF available, the frequency of withdrawal of the liquor (malignant cells may enter the liquor circulation in an episodic manner, so repeated punctures increase the likelihood of detection), the places of withdrawal of liquor (in the liquor from the tanks, the probability of detection is higher), and also the immediate fixation sample for the preservation of cell morphology. 95% of the sensitivity of the analysis is provided by a CSF fence in the amount of 30 to 50 ml (which requires 5 lumbar punctures) with immediate delivery to the laboratory. If suspicion of neurosarcoidosis is determined by the level of ACE in CSF, it is usually increased in half of the subjects. To diagnose and monitor the activity of certain types of tumors, tumor markers are used (for example, soluble CD27 in lymphoid tumors - acute lymphoblastic leukemia and non-Hodgkin's lymphoma). However, the diagnosis of Behcet's disease is made only on the basis of clinical symptoms and is not confirmed by specific changes in cerebrospinal fluid.

Treatment is aimed at the underlying disease that caused subacute or chronic meningitis.

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