What is Tuberculous Meningitis?

Tuberculous meningitis is a complication that develops from an active case of tuberculosis. When tuberculosis bacteria colonize the tissue of the central nervous system, they can cause meningitis. An uncommon condition in developed nations, tuberculosis and tuberculous meningitis are still serious health concerns in many nations. Left untreated, the disease is fatal.

Tuberculous meningitis develops in two phases. In the first phase of the infection, tuberculosis bacilli invade the body through the respiratory system. Exposure to the saliva of an infected person, through direct contact or through the air can cause a tuberculosis infection. The infection usually starts out in the lungs but can spread to other organs as the disease progresses.

Once the tuberculosis infection takes hold, a complication called tuberculous meningitis can develop. If the meninges or brain parenchyma become infected with tuberculosis, lesions can form around the central nervous system. These legions grow in size and can rupture. If these legions rupture into the subarachnoid space, which is a small cavity on the surface of the brain, the condition develops into meningitis.

Symptoms of tuberculous meningitis, which come on gradually, include fever, nausea, headache, stiffness in the neck, sensitivity to light and changes in mental states. This condition can cause seizures, hearing loss, a buildup of fluid in the brain or skull and brain damage. Left untreated, the disease is fatal.

Though tuberculous meningitis is a serious condition, there are effective treatments available. Patients are given a number of antitubercular drugs at once and continue to take the medications for at least 12 months. The disease can relapse, so frequent follow-ups are necessary. Early treatment of tuberculosis usually will prevent the development of meningitis.

Tuberculous meningitis can be positively identified through the use of a spinal tap. Collecting spinal fluids allows healthcare professionals to determine whether a patient is suffering from any form of meningitis. Tuberculosis can be identified through blood tests, chest x-rays and skin tests. The results for many of these tests may take a while, so some doctors may begin treatment if tuberculous meningitis is suspected. Patients have a better chance of both surviving the disease and not having complications if they are treated early.

This disease is relatively uncommon in developed nations. In countries with poor sanitation where many people do not have access to healthcare, tuberculosis and tuberculous meningitis are more common. The fatality rates for these diseases are also much higher in developing nations. Both tuberculosis and tuberculous meningitis are considered to be series health threats in the developing world.