Etiology Of Aseptic Meningitis With Special Reference To Tuberculous Meningitis.

¹Darwish ES, ¹Tohami SA, ¹Azmy WM, and ²El-Feky MA.

Departments of ¹Neurology and ²Microbiology, Faculty of Medicine, Assiut University, Egypt.

One hundred and seven patients with a preliminary clinical diagnosis of aseptic meningitis were subjected to the following: full neurological history and examination, routine CSF examination, CSF direct smear stained with Gram & Ziehl-Neelsen stains and india ink preparation, CSF culture for mycobacteria and fungi, detection of IgG and IgM antibodies against TB and brucella in CSF and serum samples (as a ratio between CSF/serum) by ELISA, determination of adenosine deaminase activity (ADA) in CSF and detection of TB by polymerase chain reaction (PCR) in CSF. The value of these techniques in the diagnosis of aseptic meningitis was analyzed with special reference to TB meningitis (TBM). Twenty three (21.5%) out of 107 cases were diagnosed as TBM by more than one method, 20 of them were ELISA positive as the ratio of antibodies (CSF/serum) was more than one. Seventeen cases were PCR positive, seven cases were culture positive, while only one case showed positive CSF for acid fast bacilli microscopically. Seven cases (6.5%) were diagnosed as brucella induced subacute meningitis by ELISA against LPS antigen. CNS fungal infection was diagnosed in three cases (2.8%). No specific etiological factors could be detected in the rest of the samples (74 cases), and viral study is still going on. It is concluded that ELISA is more specific if CSF/serum antibodies ratio is used for diagnosis and that PCR for TB detection in CSF is more specific technique for the diagnosis of TBM, despite being less sensitive compared to ELISA.