Comparison of cryptococcal and tuberculous meningitis.

Twenty-six patients had cryptococcal meningitis and 16 patients had tuberculous meningitis. Underlying conditions were mostly immunosuppressive diseases in patients with cryptococcosis and chronic debilitating diseases in patients with tuberculosis. There were few distinguishing charact eristics between the two infections with regard to symptoms and signs. The presence of a miliary pattern on chest roentgenogram and inappropriate secretion of antidiuretic hormone were nonspecific but helpful signs supporting a diagnosis of tuberculous meningitis; the presence of cryptococcal antigen was both a specific and sensitive indicator of cryptococcal meningitis. Acid-fast smears of CSF and the tuberculin skin test were of little help diagnostically, being positive in only 18% and 31%, respectively, of patients with tuberculous meningitis. Substantial delays in diagnosis and treatment were associated with increased mortality.