Meningeal tuberculosis also known as tubercular meningitis is caused by mycobacterium tuberculosis, the same bacterium that is responsible for tuberculosis of lung and elsewhere in the body. Meningeal tuberculosis is a disease of central nervous system. It is the most serious and dangerous form of tuberculosis infection.
Tuberculosis is a contagious disease typically spreading through cough droplets and sputum. It primarily infects the lung, but in some cases it may enter into the bloodstream infecting other organs of the body such as the intestine and membrane surrounding the brain called meninges. Adults as well as children both can suffer from TB meningitis.Its incidence is high in developing countries.
In the beginning the symptoms are vague, but gradually the symptoms become more obvious which include severe vomiting, fever, severe headache, neck rigidity, and mental confusion. Seizures may develop in some patients. Timely treatment improves the outcome of TB meningitis without causing complications.
What Causes Tuberculous Meningitis?
Meningeal tuberculosis is caused by bacteria known as mycobacterium tuberculosis. Tuberculosis infection is contagious infection and it can occur in different organs in the body. Lungs are the primary site in majority of cases. The bacilli then travels through the bloodstream to infect other organs such as the intestine, meninges of brain and spinal cord, skin etc.
When the bacilli travel into the brain, it develops small tubercles. The tubercles can burst leading to TB meningitis. It can occur abruptly or may take several months or years after the initial primary infection. The infection causes rise in the pressure causing damage to the brain cells.
Meningeal tuberculosis is much more prevalent in developing countries Asia and Africa. Anyone can develop tubercular meningitis; however, the risk is proportionately increased in people suffering from HIV infection, diabetes, and weak immunity.
Symptoms And Complications Of Meningeal Tuberculosis
The symptoms of meningeal tuberculosis are slow in onset. It may take weeks for the severe and more obvious symptoms to appear. During the early stage of infection patient may complain of tiredness, weakness, mild grade fever, loss of appetite.
With progression of the disease patient may present with other classical symptoms of TB meningitis such as fever, projectile vomiting, severe headache, neck rigidity, sensitivity to light, confusion and altered mental status, seizures, increased irritability and unconsciousness. Seizures are commonly observed in children. Without treatment the disease progresses rapidly which may lead to coma and death of the patient.
Complication Of Tuberculous Meningitis
Since archaic age, humans are known to get infected with tuberculosis. Although, tubercular meningitis is not a common manifestation of extra pulmonary tuberculosis, it is most dangerous form in terms of morbidity and fatality. Some patients may suffer from complications of meningeal tuberculosis which may be life threatening.
TB meningitis causes damage to the brain as there is increased pressure in the brain. Children may suffer from mental retardation while young adults may suffer from other neurological sequelae such as hearing loss, stroke, seizure, paralysis of facial muscles etc. These damages often are permanent and irreversible.
Diagnosis And Treatment For Meningitis Tuberculosis
Diagnosis of tuberculosis is sometime difficult and it is mainly based on the clinical symptoms, examination and abnormal finding of cerebrospinal fluid. Cerebrospinal fluid is removed through a procedure called lumbar puncture. The sample of cerebrospinal fluid is also sent to detect acid fast bacilli, although the result may vary if the volume collected is less. More specific tests such as PCR for blood and CSF are helpful to exactly diagnose the disease. Patient is also recommended by the treating doctor for CT scan of brain and X-ray chest examination.
TB meningitis is a life threatening disease. Thus early and timely treatment is essential for preventing the complications. Normally patient is prescribed 4 antibacterial drugs to kill the germs. These drugs are called anti tubercular drugs. They have excellent penetrating and bactericidal action. After two months of treatment, patient has to take 3 anti tubercular drugs for 7 to 10 months. Thus the treatment may last for 12 months.
The time period of treatment may depend on the response of drugs on the patient. It is essential for the patient to complete the full course of treatment as prescribed by the doctor or else there is always a risk of recurrence of the disease. Moreover the bacteria become resistant to many of the drugs if the disease repeats.