Please refer to the article on rhombencephalitis for a general discussion of that entity.
Studies have shown that in the USA ~5% of all TB cases involve CNS, and this percentage rises to ~25% (range 15-40%) in patients with AIDS 2. Brainstem involvement is rare, corresponding only to ~5% (range 2.5-8%) of CNS tuberculomas 1.
Brainstem tuberculomas are usually focal lesions causing focal neurological symptoms related to the involvement of a cranial nerve nuclei.
Tubercular meningitis is commonly associated in a tuberculous rhombencephalitis.
Hydrocephalus could be present when it causes obstruction to CSF flow.
CSF study 2:
- increased leukocyte count
- increased protein
- normal or low glucose levels
Diagnosis sometimes is challenging and made by the combination of clinical presentation, imaging, laboratory and treatment response.
Mycobacterium tuberculosis, also know as Koch's bacillus.
Beam-hardening artifacts limit the visualization of the brainstem on CT images and MRI is the imaging modality of choice for the assessment of patients with suspected pathology in that anatomic location. Protocols, both on CT as on MRI, should include contrast.
As systemic tuberculosis is present in ~ 55% of brainstem tuberculomas 1, further investigation such as chest radiography should be considered.
Tuberculomas are usually presented as ring-enhancing lesions with a central hypointense area (necrotic center: solid caseous, fibrotic material, and macrophages).
- isointense to grey-matter 3
- may have central region of hyperintensity representing caseation
- isointense to grey-matter
- may have central region of hypointensity representing gliosis and abundant monocyte infiltration 3
- lesions are surrounded by vasogenic oedema
T1 C+ (Gd)
- usually appears as ring-enhancement
- may appear as a conglomerate enhancing mass
- decrease in NAA/Cr
- slight decrease in NAA/Cho
- lipid-lactate peaks are usually elevated (86%) 4
Treatment and prognosis
Treatment of CNS tuberculosis is based on an anti-tubercular treatment regimen. However, multi-drug resistant tuberculosis remains a major hurdle in treatment.
- causative agent
- tuberculoma (tuberculous granuloma)
- tuberculous abscess
- miliary tuberculosis
- pulmonary tuberculosis
- cardiac tuberculosis
- intracranial tuberculosis
- tuberculous otomastoiditis
- gastrointestinal tuberculosis
- genitourinary tuberculosis
- skeletal tuberculosis
- tuberculous mastitis
- tuberculous lymphadenopathy
- tuberculous adrenalitis
- 1. Talamás O, Del Brutto OH, García-Ramos G. Brain-stem tuberculoma. An analysis of 11 patients. Arch. Neurol. 1989;46 (5): 529-35. Pubmed citation
- 2. Sahaiu-Srivastava S, Jones B. Brainstem tuberculoma in the immunocompetent: case report and literature review. Clin Neurol Neurosurg. 2008;110 (3): 302-4. doi:10.1016/j.clineuro.2007.11.002 - Pubmed citation
- 3. Kim TK, Chang KH, Kim CJ et-al. Intracranial tuberculoma: comparison of MR with pathologic findings. AJNR Am J Neuroradiol. 1995;16 (9): 1903-8. AJNR Am J Neuroradiol (abstract) - Pubmed citation
- 4. Khanna PC, Godinho S, Patkar DP et-al. MR spectroscopy-aided differentiation: "giant" extra-axial tuberculoma masquerading as meningioma. AJNR Am J Neuroradiol. 2006;27 (7): 1438-40. AJNR Am J Neuroradiol (full text) - Pubmed citation