Meningitis - Tuberculous

Tuberculous meningitis is an infection of the meninges (the membranes covering the brain and spinal cord). It is caused by Mycobacterium tuberculosis, the bacteria that causes tuberculosis.

Alternative Names

Tubercular meningitis; TB meningitis

Causes

Tuberculous meningitis is caused by the spread of Mycobacterium tuberculosis to the brain, from another site in the body. The symptoms usually begin gradually. Risk factors include a history of pulmonary tuberculosis, excessive alcohol use, AIDS, or other disorders that compromise the immune system.

Tuberculous meningitis is a very rare disorder.

Symptoms

• Seizures
• Fever
• Listlessness
• Loss of appetite
• Severe headache
• Nausea and vomiting
• Stiff neck
• Sensitivity to light (photophobia)
• Loss of consciousness

Signs and Tests

For any patient with meningitis, it is important to perform a lumbar puncture (spinal tap), where doctors take a sample of spinal fluid (known as cerebrospinal fluid, or CSF) and send it for lab tests. The following tests help diagnose tuberculous meningitis:

• CSF stain positive for mycobacterium
• CSF with high level of protein, low glucose (sugar) level, and increased number of lymphocytes
• CSF culture growing M. tuberculosis
• Polymerase chain reaction (PCR) shows CSF positive for M. tuberculosis
• Positive skin test for tuberculosis (PPD)
• Brain or meningeal biopsy showing M. tuberculosis

Treatment

Treatment involves use of several antitubercular drugs at the same time, as it does for pulmonary tuberculosis. Treatment usually lasts for at least 12 months. Systemic steroids may also be used.

Expectations (prognosis)

Tuberculous meningitis is fatal if untreated. Long-term follow up is necessary to detect recurrences (repeated infections).

Complications

Brain damage resulting from the infection may cause motor paralysis, seizures, mental impairment, and abnormal behavior.

Calling Your Health Care Provider

Go to the emergency room or call 911 if you suspect you or your child may have any form of meningitis. This condition can rapidly cause disability or death.

Call your health care provider if symptoms worsen or do not improve with treatment, or if new symptoms develop.

Prevention

In areas where tuberculosis is more common, the BCG vaccine may help prevent severe forms of tuberculosis, such as meningitis, in very young children. Otherwise, the spread of tuberculosis can be prevented by treating people who have evidence of a dormant (not-active) tuberculosis infection. A dormant infection can be detected by a positive PPD.