Tuberculosis (TB) is a contagious airborne disease that typically affects the lungs. TB is caused by a bacterium called Mycobacterium tuberculosis. If a TB infection is not treated promptly, the bacterium can travel through the bloodstream. It can infect other organs and tissues in the body.
Sometimes, the bacterium will travel to the membranes surrounding the brain and spinal cord (the meninges). Infection of the meninges can result in the development of a life-threatening condition known as meningeal tuberculosis. Meningeal tuberculosis is also known as tubercular meningitis or TB meningitis.
What Are the Risk Factors for Developing Meningeal Tuberculosis?
TB and TB meningitis can develop in children and adults of all ages. However, patients with specific health problems are at greater risk for developing these conditions. Risk factors for TB meningitis include having a history of:
- excessive alcohol use
- weakened immune system
- diabetes mellitus (several disorders in which your blood sugar is high either because your pancreas doesn’t produce enough insulin, or your cells are resistant to insulin)
TB meningitis is rarely found in the United States. In developing countries, children between birth and 4 years of age are most likely to develop this condition.
What Are the Symptoms of Meningeal Tuberculosis?
Symptoms of TB meningitis typically begin slowly at first. They become more severe over a period of weeks. During the early stages of the infection, symptoms typically include:
- low-grade fever
As the disease progresses, the symptoms will become more serious. Classic symptoms of meningitis (e.g., stiff neck, headache, light sensitivity) are not always present. The following symptoms are frequently seen:
- changes in mental status (confusion)
- nausea and vomiting
How Is Meningeal Tuberculosis Diagnosed?
To diagnose TB meningitis, your doctor will perform a physical exam. Your doctor will check for symptoms of the condition. These include:
- rapid heart rate
- stiff neck
- changes in mental status
If you have symptoms of TB meningitis, your doctor may order additional tests to confirm a diagnosis. This may include a lumbar puncture (spinal tap). The spinal tap will require your doctor to collect fluid from your spinal column. The fluid will be sent to a laboratory for analysis to confirm your condition.
Your doctor may also order other tests to evaluate your health. These tests include:
- biopsy of the meninges
- blood culture
- chest X-ray
- CT scan of the head
- skin test for tuberculosis (PPD)
What Complications Are Associated with Meningeal Tuberculosis?
The complications of TB meningitis are significant and life-threatening. They include:
- hearing loss
- increased pressure in the brain (intracranial pressure)
- brain damage
Increased pressure in the brain can cause permanent and irreversible brain damage.
How Is Meningeal Tuberculosis Treated?
If you have TB meningitis your doctor will prescribe medications called anti-TB drugs. These include:
These drugs will treat both the TB meningitis and TB infection. Your doctor may also prescribe systemic steroids. Steroids will reduce complications associated with the condition. Depending on the severity of the infection, treatment may last as long as 12 months. In some cases, you may need to receive treatment in the hospital.
How Can Meningeal Tuberculosis be Prevented?
To prevent the development of TB meningitis, TB infections must be controlled. In communities where TB is common, the BCG (Bacillus Calmette-Guérin) vaccine can be used to control the spread of the disease. This vaccine is effective for controlling TB infections in young children.
Treatment of patients with non-active or dormant TB infections can also help control the spread of the disease. Non-active or dormant infections occur when a person tests positive for TB but does not have any symptoms of the disease. Patients with dormant infections are still capable of spreading the disease.
What Is the Outlook for Patients with Meningeal Tuberculosis?
If you are diagnosed with TB meningitis, your outlook will depend on the severity of your symptoms. Your outlook will also depend on how quickly you seek treatment. Early diagnosis of your infection will enable your doctor to provide treatment. If treatment is received before complications develop, the outlook will be good.
Outlook for patients with TB meningitis that develop brain damage or stroke is not as good. For these patients, brain damage will be permanent and will impact health over the long-term. The development of increased intracranial pressure is a strong indication of a poor outlook for the patient.
You will need to be monitored by your doctor after being treated for TB meningitis. If you have had this infection, it is more likely to develop again. Your doctor can monitor your health to detect the infection early.