Tuberculous Meningitis (TBM)

Question 1

What is TBM?

Answer 1

Is Mycobacterium tuberculosis infection of the meninges.

In TBM, Bacilli seed to the meninges, resulting in the formation of small focu called “Rich foci”.

The incidence of TBM mirrors TB in the community, and is still the most common type of chronic CNS infection in developing countries.

In Children there is no gender, in adults 2x as common in males.

Worldwide, however TBM is most common in the first 5 years od life

Question 2

Presentation of TBM?

Answer 2

TBM usually takes the form of meningitis that causes an acute to subacute illness characterised by fever, headache, drowsiness, meningitis, & confusion over a period of approximately 2-3 weeks.

• Focal neurologic deficits, including monoplegia, hemiplegia, aphasia, & tetraparesis, have been reported.
• Visual symptoms include visual impairment or blindness & occasionally painful ophthalmoplegia.
• TREMOR IS THE MOST COMMON MOVEMENT DISORDER SEEN.

Question 3

What is the investigation for TBM?

Answer 3

CSF culture for M.Tuberculosis will yield positive results in up to 80%
CT & MRI reveal hydrocephalus, basilar meningeal thickening, infracts, oedema & tuberculomas.

• On CT scans, tuberculomas appear as low- or high density round or lobulated masses.

Question 4

Treatment for TBM?

Answer 4

Anti-tuberculosis regimen is started after confirmation of diagnosis.

The best antimicrobial agents in the treatment of TBM include isoniazide, rifampicin, pyrazinamide, & streptomycin all of which enter CSF readily in the presence of meningeal inflammation.

• Ethambutol is less effective in meningeal disease unless used in high doses.
• Treatment of complications (eg Drainage of hydrocephalus) may also be performed.