| Tuberculous meningitis accounts for 7-12% of extrapulmonary tuberculosis. The mortality and disability rate of TBM is more than 50%. It is extremely important to treat TBM patients as early as possible to improve the prognosis. TBM cases in specialized hospitals are usually associated with active pulmonary tuberculosis, and anti TB treatment will not be delayed in general. The majority of TBM cases in comprehensive hospitals usually have no evidence of tuberculosis outside the CNS. In addition, the sensitivity of pathogenic examination is low and the symptoms of early stage TBM are often nonspecific. Therefore, the TBM cases in comprehensive hospitals are easily misdiagnosis and delayed treatment. In order to avoid misdiagnosis, Lancet scoring system has been widely used in the diagnosis of non-definite meningitis patients. Lancet scoring system standards and relative weight distribution based on the review of literature and the expert consensus, its accuracy has not yet been evaluated. Therefore, it is necessary to describe the clinical features of TBM in comprehensive hospitals and evaluate the diagnosis effect of Lancet scoring system.Objective: We have designed a multicenter, retrospective and descriptive study to analysis the clinical characteristics of patients with TBM and the other infectious meningitis in comprehensive hospitals. The diagnostic efficacy of Lancet TBM scoring system, which is widely used in clinical diagnosis, is assessed for distinguishing between TBM and the other infectious meningitis.Method: This study was divided into two parts. First, we describe the demographic characteristics, clinical manifestation, laboratory examinations and neuroimaging examinations of TBM cases in comprehensive hospitals by the methods of retrospective analysis. Secondly, we compared the clinical features of TBM and the other common infectious meningitis in comprehensive hospitals. Then the diagnosis efficacy of Lancet TBM scoring system was evaluated by ROC curve. All data were compared using epidemiological software Open Epi and statistical analysis software SPSS 19.0.Results:1. More than 85% of definite TBM cases in comprehensive hospitals had not detected the presence of tuberculosis outside the central nervous system. The vast majority of cases showed only nonspecific symptoms and the frequency of systemic symptoms of tuberculosis was lower than 5%. 67.4% of cases had no characteristic changes in neuroimaging examination. According to the CSF criteria of Lancet scoring system, the results of CSF examination were not typical in 20-60% of definite cases. The duration of symptoms of definite cases was 12(7, 26.5) days, which had a negative impact on the prognosis.2. Patients aged 15-36 years had stronger immune response to M.tuberculosis than patients over 36 years of age, and were more likely to be complicated with pulmonary tuberculosis. Therefore, it is more important to start corticosteroids adjuvant therapy and exclude pulmonary tuberculosis in patients aged 15-36 years. The incidence of cerebral infarction in patients over 36 years of age(30.7%) was about 2.5 times higher than that in patients aged 15-36 years(12.6%). Therefore, patients over 36 years of age should consider using aspirin to improve the prognosis.3. The duration of symptoms of MRC2 patients was 15(7, 30) days, longer than the other two groups of patients. The low rate of meningeal irritation sign may be the cause of delay in diagnosis. Therefore, attention should be given to the focal neurological deficit patients to prevent misdiagnosis.4. The duration of symptoms of non-definite TBM patients was 20(10, 32.5) days, which was significantly longer than definite TBM patients. The proportion of MRC3 in non-definite TBM patients was lower than that in definite TBM patients. The reason for microbiology undiagnosed may be that the number of M.tuberculosis in the CSF was low. It is necessary to repeat microbiological examination and increase the volume of CSF samples.5. The AUC of Lancet scoring system was 0.76. The specificity and sensitivity of probable TBM criterion were 98.8% and 14.3% to identify TBM and the other common infectious meningitis. Anti TB and corticosteroids adjuvant therapy should be started immediately. The specificity and sensitivity of possible TBM criterion were 26.8% and 94.0%. Each available microbiological diagnosis method should be used to exclude other possible diagnosis before the start of anti tuberculosis therapy. Because 6% of TBM cases may be misdiagnosised, it should be assessed regularly in order to avoid misdiagnosis the patients whose diagnostic score was less than 6 points.Conclusion:Most of definite TBM cases in comprehensive hospitals had not detected the presence of tuberculosis outside the central nervous system. The vast majority of cases showed only nonspecific symptoms. More than half of definite TBM cases were not typical in neuroimaging examination and CSF examination. It is more important to start corticosteroids adjuvant therapy and exclude pulmonary tuberculosis in patients aged 15-36 years. Patients over 36 years of age should consider using aspirin to improve the prognosis. For suspected TBM patients in comprehensive hospitals. Such as Lancet diagnostic score is probable TBM, anti tuberculosis therapy and corticosteroids adjuvant therapy should be started immediately. Such as Lancet diagnostic score is possible TBM, each available microbiological diagnosis method should be used to exclude other possible diagnosis before the start of anti tuberculosis therapy. It should be assessed regularly to avoid missed diagnosis for the patients whose diagnostic score was less than 6 points. |
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