Methods: We prospectively enrolled adult patients (≥16 years) with suspected TBM admitted to our hospital from April 2008 to March 2014. We evaluated the utility of the uniform case definition for differentiating definite TBM, VM, and BM. Patients with TBM were categorized as definite TBM (AFB seen on CSF microscopy, positive CSF M. tuberculosis culture, or positive CSF M. tuberculosis PCR), probable TBM (diagnostic score ≥12), and possible TBM (diagnostic score 6–11) according to the uniform case definition. A diagnosis of definite VM or BM was made if the pathogens were identified by PCR or culture in the CSF or blood.
Results: 93 adult patients were treated for TBM; 27 (29%) were classified as definite TBM, 25 (27%) as probable TBM, and 41 (44%) as possible TBM. Of these 93 patients with TBM, the 27 patients with definite TBM were finally analyzed. We also identified 23 PCR-confirmed VM and 20 culture-confirmed BM. When we calculated diagnostic score independent of culture and CSF PCR in patients with the 27 patients with definite TB, 22 (81%) were scored as probable TBM and 5 (19%) as possible TBM. Overall, ‘probable TBM’ criteria differentiated definite TBM from both VM and BM with a sensitivity of 81% (22/27) and specificity of 98% (42/43), while the ‘possible TBM’ criteria identified definite TBM with a sensitivity of 100% (27/27) and specificity of 60% (26/43). Among the 23 patients with definite VM, 13 (57%) were scored as unlikely TBM and 10 (43%) as possible TBM. For 20 patient diagnosed with definite BM, 13 (65%) were scored as unlikely TBM, 1 (5%) as probable TBM and 6 (30%) as possible TBM.
Conclusion: These results indicate that some cases of VM or BM could masquerade as TBM, especially severe case of VM or indolent case of BM. Our data suggest that case definition may be useful for differentiating TBM from VM or BM, but there was substantial overlap in clinical and laboratory features. To avoid fatalities due to delayed treatment and unnecessary exposure to anti-TB drug toxicity, a rapid and accurate tool for diagnosing TBM is required.
Y. R. Jang,
K. H. Park, None
M. S. Lee, None
J. K. Kang, None
S. A. Lee, None
S. H. Kim, None