Meningitis - tuberculous

Definition

Tuberculous meningitis is an infection of the the membranes covering the brain and spinal cord (meninges).

See also:

• Meningitis
• Meningitis - cryptococcal
• Meningitis - gram-negative
• Meningitis -
• Meningitis - meningococcal
• Meningitis - pneumococcal
• Meningitis - staphylococcal

Alternative Names

Tubercular meningitis; TB meningitis

Causes, incidence, and risk factors

Tuberculous meningitis is caused by Mycobacterium tuberculosis, the bacteria that causes tuberculosis. The bacteria spreads to the brain from another site in the body.

Risk factors include a history of:

• AIDS
• Excessive alcohol use
• Other disorders that compromise the immune system
• Pulmonary tuberculosis

Tuberculous meningitis is a very rare disorder.

Symptoms

The symptoms usually begin gradually, and may include:

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

Signs and tests

For any patient with meningitis, it is important to perform a lumbar puncture ("spinal tap"), in which doctors take a sample of spinal fluid (known as cerebrospinal fluid, or CSF) and send it for lab tests.

When the health care provider suspects tuberculosis, there may be a need to get many CSF samples over time to increase the chance of a diagnosis. This may require many lumbar punctures.

The following tests help diagnose tuberculous meningitis:

• Biopsy of the brain or meninges
• CSF culture
• CSF stain
• CSF test of protein, glucose (sugar) level, and lymphocytes
• Polymerase chain reaction (PCR)
• Skin test for tuberculosis (PPD)

Treatment

Treatment involves 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 life-threatening if untreated. Long-term follow-up is needed to detect repeated infections (recurrences).

Complications

Brain damage resulting from the infection may cause:

• Abnormal behavior
• Mental impairment
• Motor paralysis
• Seizures

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.

Treating people who have evidence of a non-active (dormant) tuberculosis infection can prevent the spread of tuberculosis. A dormant infection can be detected by a positive PPD.

References

Swartz MN. Meningitis: bacterial, viral, and other. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007: chap 437.