Chronic meningitis

Chronic meningitis is an inflammatory disease that, unlike the acute form, develops gradually over several weeks (sometimes more than one month). Symptoms of the disease are similar to those of acute meningitis: patients have headache, high fever, and sometimes neurological disorders. There are also characteristic pathological changes in the cerebrospinal fluid.[1]

Epidemiology

One of the most pronounced outbreaks of meningitis occurred in 2009 in the epidemically dangerous zones of West Africa - in the region of the "meningitis belt" located south of the Sahara, between Senegal and Ethiopia. The surge affected countries such as Nigeria, Mali, Niger: almost 15 thousand cases were registered. Similar outbreaks in these regions occur regularly, approximately every 6 years, and the causative agent of the disease is most often meningococcal infection.

Meningitis, including chronic, is characterized by a rather high risk of death. Complications often develop, immediate and remote.

In European countries, the disease is recorded much less often - about 1 case per hundred thousand of the population. Children are more likely to get sick (about 85% of cases), although in general people of any age can get sick. Meningitis is especially common in infants.

Pathology was first described by Hippocrates. The first officially recorded meningitis outbreaks occurred in the 19th century in Switzerland, North America, then in Africa and Russia. At that time, the lethality of the disease was more than 90%. This figure dropped significantly only after the invention and introduction into practice of a specific vaccine. The discovery of antibiotics also contributed to the reduction in mortality. By the 20th century, epidemic outbreaks were recorded less and less. But even now, acute and chronic meningitis are considered deadly diseases that require immediate diagnosis and treatment.

Causes of the chronic meningitis

[11]

the causative agent of Lyme disease (Borrelia Burgdorferi);

fungal infection (including Cryptococcus neoformans, Cryptococcus gatti [3]

protozoa (for example, Toxoplasma gondii);

viruses (in particular, enteroviruses).

Chronic meningitis is often diagnosed in HIV-infected patients, especially against the background of the addition of a bacterial and fungal infection. [4]In addition, the disease may have a non-infectious etiology. So, chronic meningitis is sometimes found in patients with sarcoidosis, [5]systemic lupus erythematosus, [6]rheumatoid arthritis, Sjögren's syndrome, Behcet's disease, lymphoma, leukemia.[7]

Fungal chronic meningitis can develop after injection of corticosteroid drugs into the epidural space in violation of the rules of asepsis: such injections are practiced to relieve pain in patients with sciatica. In this case, signs of the disease occur for several months after the introduction.[8], [9]

Cerebral aspergillosis occurs in approximately 10-20% of patients with invasive disease and is the result of hematogenous spread of the organism or direct spread of rhinosinusitis.[10]

In some cases, people are diagnosed with chronic meningitis, but no infection is found during the studies. In such a situation, one speaks of idiopathic chronic meningitis. It is noteworthy that this type of disease does not respond well to treatment, but often goes away on its own - self-healing occurs.

Risk factors

Provoking factors in the development of chronic meningitis can be almost any infectious pathology that causes an inflammatory process. A weakened immune system further increases the risk.

A person can become infected with an infectious disease from a patient or a bacteriocarrier (virus carrier) - an outwardly healthy person who is contagious to others. The infection can be transmitted by airborne droplets, or by household contact in the usual daily conditions - for example, when using shared cutlery, kissing, as well as during cohabitation (camp, barracks, hostel, etc.).

The risk of developing chronic meningitis increases significantly in children with immature immune protection (infancy), in people traveling to epidemically dangerous regions, in patients with immunodeficiency states. Smoking and alcohol abuse also have an adverse effect.

Pathogenesis

In the pathogenetic mechanism of the development of chronic meningitis, infectious-toxic processes play a leading role. They are caused by large-scale bacteremia with a pronounced decay of bacteria and the release of toxic products into the blood. Endotoxin exposure is due to the release of toxins from the cell walls of the pathogen, which entails a violation of hemodynamics, microcirculation, leads to intense metabolic disorders: oxygen deficiency and acidosis gradually increase, hypokalemia is aggravated. The coagulation and anticoagulation systems of the blood suffer. At the first stage of the pathological process, hypercoagulation is observed with an increase in the level of fibrinogen and other coagulation factors, and at the second stage, fibrin falls out in small vessels, and blood clots form. With a further decrease in the level of fibrinogen in the blood, the likelihood of hemorrhages, bleeding into various organs and tissues of the body increases.

The entry of the pathogen into the membranes of the brain becomes the start for the development of symptoms and pathomorphological picture of chronic meningitis. First, the inflammatory process affects the soft and arachnoid membrane, then it can move to the substance of the brain. The type of inflammation is predominantly serous, and if left untreated, it turns into a purulent form. A characteristic feature of chronic meningitis is a gradually increasing lesion of the spinal roots and cranial nerves.

Symptoms of the chronic meningitis

The main symptoms in chronic meningitis are persistent headache (possibly in combination with tension of the occipital muscles and hydrocephalus), radiculopathy with cranial nerve neuropathy, personality disorders, memory and mental performance impairment, as well as other cognitive impairment. These manifestations can occur simultaneously or separately from each other.

Due to the excitation of the nerve endings of the membranes of the brain, severe pain in the head is complemented by pain in the neck and back. Hydrocephalus and increased intracranial pressure may develop, which, in turn, causes increased headache, vomiting, apathy, drowsiness, irritability. Edema of the optic nerves, deterioration of visual function, paresis of the upward gaze are noted. There may be damage to the facial nerve.

With the addition of vascular disorders, cognitive problems, behavioral disorders, and convulsions appear. Acute cerebrovascular accidents and myelopathy may develop.

With the development of basal meningitis against the background of deterioration of vision, weakness of the mimic muscles, deterioration of hearing and smell, impaired sensitivity, weakness of the masticatory muscles are found.

With the aggravation of the inflammatory process, complications can develop in the form of edema and swelling of the brain, infectious-toxic shock with the development of DIC.

First signs

Since chronic meningitis progresses slowly, the first signs of pathology do not immediately make themselves felt. The infectious process is manifested by a gradual increase in temperature, headache, general weakness, loss of appetite, as well as symptoms of an inflammatory reaction outside the central nervous system. In immunocompromised individuals, body temperature may be within the normal range.

Chronic meningitis should be ruled out first if the patient has persistent persistent headache, hydrocephalus, progressive cognitive impairment, radicular syndrome, cranial neuropathy. With these signs, a lumbar puncture should be performed, or at least an MRI or computed tomography should be performed.

The most likely initial symptoms of chronic meningitis are:

• temperature increase (stable indicators within 38-39 ° C);
• headache;
• psychomotor disorders;
• deterioration in gait;
• double vision;
• convulsive muscle twitching;
• visual, auditory, olfactory problems;
• meningeal signs of varying intensity;
• violations of the mimic muscles, tendon and periosteal reflexes, the appearance of spastic themes and paraparesis, rarely - paralysis with hyper or hypoesthesia, coordination disorders;
• cortical disorders in the form of mental disorders, partial or complete amnesia, auditory or visual hallucinations, euphoric or depressive states.

Symptoms of chronic meningitis can last for months or even years. In some cases, patients may notice a visible improvement, after which a relapse occurs again.

Complications and consequences

The consequences of chronic meningitis are almost impossible to predict. In most cases, they develop in the long term, and can be expressed in the following disorders:

• neurological complications: epilepsy, dementia, focal neurological defects;
• systemic complications: endocarditis, thrombosis and thromboembolism, arthritis;
• neuralgia, paralysis of cranial nerves, contralateral hemiparesis, damage to the organs of vision;
• hearing loss, migraine.

In many cases, the likelihood of developing complications depends both on the underlying cause of chronic meningitis and on the state of the person's immune system. Meningitis provoked by a parasitic or fungal infection is more difficult to cure, has a tendency to re-develop (especially in HIV-infected patients). Chronic meningitis, which developed against the background of leukemia, lymphoma, or cancer, has a particularly unfavorable prognosis.

Diagnostics of the chronic meningitis

If there is a suspicion of chronic meningitis, it is necessary to conduct a complete blood count and perform a lumbar puncture to study the cerebrospinal fluid (if there are no contraindications). After the lumbar puncture, the blood is examined to assess the level of glucose.

Additional tests:

• blood chemistry;
• determination of the leukocyte formula;
• cultural study of blood with PCR.

In the absence of contraindications, lumbar puncture is performed as soon as possible. A CSF sample is sent to the laboratory: this procedure is fundamental for the diagnosis of chronic meningitis. The standard defines:

• the number of cells, protein, glucose;
• Gram stain, culture, PCR.

The following signs may indicate the presence of meningitis:

• increased pressure;
• turbidity of the cerebrospinal fluid;
• increased number of leukocytes (mainly polymorphonuclear neutrophils);
• increased protein levels;
• low value of the ratio of glucose in the cerebrospinal fluid and blood.

Other biological materials, such as urine or sputum samples, may be collected for bacterial culture.

Instrumental diagnostics may include magnetic resonance and computed tomography, a biopsy of altered skin (with cryptococcosis, systemic lupus erythematosus, Lyme disease, trypanosomiasis) or enlarged lymph nodes (with lymphoma, tuberculosis, sarcoidosis, secondary syphilis or HIV infection).

A thorough examination by an ophthalmologist is carried out. It is possible to identify uveitis, dry keratoconjunctivitis, iridocyclitis, deterioration of visual function due to hydrocephalus.

General examination reveals aphthous stomatitis, hypopyon, or ulcerative lesions - in particular, characteristic of Behcet's disease.

Enlargement of the liver and spleen may indicate the presence of lymphoma, sarcoidosis, tuberculosis, brucellosis. In addition, chronic meningitis can be suspected if there are additional sources of infection in the form of purulent otitis media, sinusitis, chronic pulmonary pathologies, or provoking factors in the form of intrapulmonary blood shunting.

It is very important to correctly and fully collect epidemiological information. The most important anamnestic data are:

• the presence of tuberculosis or contact with a tuberculosis patient;
• travel to epidemiologically unfavorable regions;
• the presence of immunodeficiency states or a sharp weakening of immunity.[12]

Differential diagnosis

Differential diagnostics is carried out with various types of meningitis (viral, tuberculous, borreliosis, fungal, provoked by protozoa), as well as:

• with aseptic meningitis associated with systemic pathologies, neoplastic processes, chemotherapy;
• with viral encephalitis;
• with brain abscess, subarachnoid hemorrhage;
• with neoblastoses of the central nervous system.

When making a diagnosis of chronic meningitis, they are based on the results of a study of cerebrospinal fluid, as well as information obtained during the etiological diagnosis (seeding, polymerase chain reaction).[13]

Treatment of the chronic meningitis

Depending on the origin of chronic meningitis, the doctor prescribes the appropriate treatment:

• if tuberculosis, syphilis, Lyme disease, or another bacterial process is diagnosed, antibiotic therapy is prescribed according to the sensitivity of specific microorganisms;
• if there is a fungal infection, antifungal agents are prescribed, mainly Amphotericin B, Flucytosine, Fluconazole, Voriconazole (by mouth or by injection);
• if the non-infectious nature of chronic meningitis is diagnosed - in particular, sarcoidosis, Behcet's syndrome - corticosteroid drugs or immunosuppressants are prescribed for a long time;
• if cancerous metastases are found in the membranes of the brain, radiation therapy of the head area and chemotherapy are combined.

In chronic meningitis provoked by cryptococcosis, Amphotericin B is prescribed together with Flucytosine or Fluconazole.

In addition, symptomatic treatment is used: according to indications, analgesics, non-steroidal anti-inflammatory drugs, diuretics and detoxification drugs are used.[14]

Prevention

Preventive measures to prevent the development of chronic meningitis include the following recommendations:

• compliance with the rules of personal hygiene;
• avoiding close contact with sick people;
• inclusion in the diet of food rich in vitamins and minerals;
• during periods of a surge in seasonal incidence, avoiding staying in crowded areas (especially indoors);
• drinking only boiled or bottled water;
• the use of thermally processed meat, dairy and fish products;
• avoiding swimming in stagnant water;
• carrying out wet cleaning of residential premises at least 2-3 times a week;
• general hardening of the body;
• avoidance of stress, hypothermia;
• maintaining an active lifestyle, supporting physical activity;
• timely treatment of various diseases, especially infectious origin;
• quitting smoking, drinking alcohol and drugs;
• refusal to self-medicate.

In many cases, chronic meningitis can be prevented by timely diagnosis and treatment of systemic diseases.