Characteristics of cerebrospinal fluid in tuberculous meningitis.

A retrospective study of 84 cases of tuberculous meningitis from a ten-year period is presented. Lumbar punctures had been performed, and the dynamics of cytologic changes in the cerebrospinal fluid (CSF) had been followed weekly during the course of the disease. The typical clinical picture, the course of the disease and cytologic characteristics of the CSF are noted. Of particular interest were some cases presenting atypical cytologic, as well as clinical, pictures of tuberculous meningitis. These patients had pleocytosis lasting as long as two years. In the first ten days, neutrophils predominated (60% to 80%); then mononuclear cells, such as lymphocytes, lymphoid cells, monocytoid cells and macrophages, became predominant. From the third week of the disease, plasmocytes (20%) were found in 30% of these cases. The presence of reticulomonocytes and reticulohistiocytic cells that could hardly be classified was also noted. By detailed analysis of the cytologic changes in the CSF, the suggestion of a diagnosis of tuberculous meningitis can be made before Koch's bacilli are found, even when the clinical picture and course of the disease are atypical.