Meningitis - tuberculous

Alternative names

Tubercular meningitis, TB meningitis

Definition

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

Causes, incidence, and risk factors

Tuberculous meningitis is caused by spread of Mycobacterium tuberculosis from another site in the body. The onset of symptoms is usually gradual. Risk factors include a history of pulmonary tuberculosis, excessive alcohol use, AIDS, and/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 a needle is inserted into the back of the patient and spinal fluid (known as cerebrospinal fluid, or CSF) is sampled. The following tests help diagnose tuberculous meningitis:

• Spinal fluid (CSF) stain positive for mycobacterium
  
• CSF with high protein, low glucose and increased lymphocytes
  
• CSF culture growing M. Tuberculosis
  
• CSF positive for M. tuberculosis PCR
  
• Positive skin test for Tuberculosis
  
• Brain or meningeal biopsy showing M. tuberculosis
  

Treatment
Treatment involves use of antitubercular drugs as for pulmonary tuberculosis. Systemic steroids may also be used.

Expectations (prognosis)