Tuberculous meningitis: causes, symptoms, treatment, prognosis

What is tuberculous meningitis?

Tuberculous meningitis (TBM) is a form meningitischaracterized by inflammation of the membranes around the brain (meninges) or spinal cord caused by a specific bacterium known as Mycobacterium tuberculosis (Koch's bacillus).

Tuberculous meningitis is the most common form tuberculosis (TB) of the central nervous system and is characterized by very high morbidity and mortality. TBM is usually a subacute illness with symptoms that may persist for several weeks before being diagnosed.

Antibiotics and other medications are usually prescribed to treat the infection.

Despite great advances in immunology, microbiology and drug development, tuberculosis remains one of the most pressing public health problems. Poverty; lack of a functioning public health infrastructure; lack of funding to support basic research aimed at developing new drugs, diagnostics and vaccines; and the HIV co-epidemic continues to fuel the ongoing tuberculosis epidemic.

With late diagnosis, tuberculosis of the meninges and the central nervous system proceeds unfavorably, often ends lethal or leaves serious complications, often leading to disability (paralysis, decreased intelligence, blindness, epileptic syndromes).

Signs and symptoms

Tuberculous meningitis affects the central nervous system. Mild headaches and behavioral changes may be noticed at first. Fever, severe headache, stiff neck, and vomiting may also occur. Symptoms in older children and adults can progress from irritability to confusion, drowsiness, and stupor, which can lead to coma.

If left untreated, this disorder can lead to epilepsy, hydrocephalus (accumulation of fluid in the brain cavity), deafness, mental retardation, paralysis of one side of the body (hemiparesis), blindness and other neurological disorders.

Clinical classification

• Basilar tuberculous meningitis (occurs most often - up to 90%), distinguish between tuberculous meningoencephalitis and the spinal form of tuberculous meningitis. In basilar meningitis, the meningeal syndrome and damage to the cranial nerves come to the fore without any other complications. This group also includes erased forms of meningitis, as well as those forms in which there is no damage to the cranial nerves.
• Meningoencephalitic, or meningovascular form - clinically characterized by a combination of meningeal syndrome with manifestations of focal lesions of the brain substance (aphasia, hemiparalysis and hemiparesis).
• Spinal shape - in the forefront in the clinical picture are the phenomena that indicate the defeat of the substance, membranes or roots of the spinal cord, mainly of the lower extremities, and disorders of the pelvic function organs.

With uncomplicated basilar meningitis, the cure can be complete, without residual effects or with residual effects of a functional nature associated with the drug-toxic effect of streptomycin in its subarachnoid administered. In meningoencephalitic meningitis, severe lesions of the locomotor system, which recover over a long time, may come to the fore as residual effects. Residual effects in spinal meningitis require longer treatment times and may cause irreversible or difficult reverse development of movement disorders in the form of paraplegia or paraparesis associated with adhesive processes in the region of the spinal roots brain.

Causes and risk factors

Tuberculous meningitis is a rare complication that occurs in some patients with tuberculosis (TB), especially miliary tuberculosis. It can also occur in people who have been exposed to the bacteria that cause tuberculosis. This form of meningitis is caused by a specific bacteria known as Mycobacterium tuberculosis.

Risk factors for developing tuberculous meningitis include a history of:

• HIV /AIDS;
• excessive alcohol consumption;
• a weakened immune system;
• diabetes.

Tuberculous meningitis is rare in Russia due to high vaccination rates. In low-income countries, the disease most often develops in children between the ages of 4 and 4.

Affected populations

Tuberculous meningitis is the seventh leading cause of death and disability worldwide. In 1997, TBM was the fifth most common form of extrapulmonary tuberculosis. TBM accounts for 5.2% (186) of all cases of exclusively extrapulmonary disease and 0.7% of all reported cases of tuberculosis.

TB meningitis is usually found in children between the ages of 1 and 5, although it can occur at any age.

- International statistics.

WHO estimates that one third of the world's population is infected with tuberculosis (TB). A 2003 WHO publication states that there are 8 million new cases of tuberculosis annually and 2 million deaths annually. An estimated 8.8 million new cases of TB were reported worldwide in 2005, and 7.4 million in Asia and sub-Saharan Africa. A total of 1.6 million people have died from tuberculosis, including 195,000 HIV-infected patients.

In 2005 the incidence of tuberculosis has been stable or declining in all 6 WHO regions. However, the total number of new cases of tuberculosis was still growing slowly; the load continues to grow in the regions of Africa, the Eastern Mediterranean and Southeast Asia. In many parts of Africa and Asia, the annual incidence of tuberculosis for all ages is approximately 2%, which could result in approximately 200 cases of tuberculosis per 10,000 people in year. About 15-20% of these cases occur in children under 15 years of age.

The prevalence of TB among children worldwide is difficult to estimate because data are scarce and poorly organized. The available reports grossly underestimate the true incidence. The lack of follow-up testing in most parts of the world limits the ability to estimate the prevalence of the disease. In developing countries, there are 1.3 million TB cases and 40,000 TB deaths in children under 15 years of age each year. In developing countries, 10–20% of people who die from tuberculosis are children. TB meningitis complicates about 1 in every 300 untreated primary TB infections.

Symptomatic disorders

Symptoms of the following disorders may mimic those of tuberculous meningitis. Comparisons can be useful for differential diagnosis:

• In general, any meningitis characterized by inflammation of the membranes around the brain or spinal cord. This inflammation can be caused by various types of bacteria, viruses, fungi, cancers, or reactions to certain injections into the spinal canal.
• Encephalitis - a brain infection caused by one of several different types of viruses. Encephalitis can also be caused by hypersensitivity caused by certain other non-viral foreign proteins. Many of the symptoms are similar to those of tuberculous meningitis, such as a stiff neck, altered reflexes, confusion, speech disorders, epilepsy, paralysis, and coma.

Diagnostics

Diagnostic measures are carried out jointly by phthisiatricians and neurologists. The main stage in the diagnostic process is the examination of the spinal cord fluid, a sample of which is obtained using a lumbar puncture.

Liquor in tuberculous meningitis is excreted with increased pressure up to 500 mm of water. Art. There is the presence of cytosis, which in the early stages of pathology has a neutrophilic-lymphocytic character, but later tends more to lymphocytic. The quantitative indicators of chlorides and glucose decrease.

The lower the glucose concentration values, the more difficult the forthcoming treatment is. Based on this, doctors choose the appropriate therapy method. Differential diagnosis of tuberculous meningitis is carried out using computed tomography (CT) and magnetic resonance imaging (MRI) of the brain.

Prophylaxis

The best way to prevent TB meningitis is to prevent infection with Koch's bacillus. In communities where tuberculosis is common, BCG (Bacillus Calmette-Guérin) vaccination can help control the spread of the disease. This vaccine is effective in fighting tuberculosis infections in young children.

Treating people with inactive or dormant TB infections can also help control the spread of the disease. Inactive or dormant infections are when a person tests positive for TB but has no symptoms of the disease. People with dormant infections are still able to spread the disease.

Standard treatments

Treatment of TB patients of the meninges and central nervous system is complex and is carried out in specialized institutions. Treatment in the intensive phase is carried out in a hospital setting and in the support phase - on an outpatient basis.

- Bed rest.

One of the main components of treatment is strict bed rest until the cerebrospinal fluid is sanitized and disappears. meningeal signs, with a gradual step-by-step expansion of the regime: transfer to a sitting position, transfer to half-bed mode. Each stage should start with a minimum load and a gradual increase in time. The transfer of the patient from one stage to the next stage of the expansion of the regimen is carried out with the permission of a neuropathologist, ophthalmologist.

- Medical treatment.

Four drugs are commonly used to treat tuberculosis:

• isoniazid;
• rifampicin;
• pyrazinamide;
• ethambutol.

Treatment for tuberculous meningitis includes the same medications except ethambutol. Ethambutol does not penetrate well through the mucous membrane of the brain. Fluoroquinolones such as moxifloxacin or levofloxacin are usually used instead.

The doctor may also prescribe systemic steroids (corticosteroids). Steroids will reduce the complications associated with the disease.

Depending on the severity of the infection, treatment can take up to 12 months.

Forecast

The outcome of tuberculous meningitis depends on the stage of the disease at which the disease is diagnosed, the severity of the patient's condition and complications. In stage I of the disease, cure occurs in all patients, and residual changes are minimal. With treatment started in stage II of the disease, half of the survivors remain severely impaired. Treatment, begun in stage III of tuberculous meningitis, saves the lives of only 50% of patients, and they, as a rule, experience complications and remain severely disabled.

Possible complications

Complications of tuberculous meningitis are significant and in some cases life-threatening. They include:

• epileptic seizures;
• hearing loss;
• increased pressure in the brain;
• brain damage;
• stroke;
• death.

Increased pressure in the brain can lead to permanent brain damage. If the patient's vision changes and there are headaches at the same time, you should immediately consult a doctor. This could be a sign of increased pressure in the brain.