Post-neurosurgical and spontaneous gram-negative bacillary meningitis in adults.

In order to evaluate the clinical aspects of gram-negative bacillary meningitis (GNBM) we reviewed the charts of 20 adult patients with the discharge diagnosis of meningitis caused by gram-negative bacilli (bacteriologically proved) seen between 1973 and 1984. Nine patients had post-neurosurgical (post-NS) GNBM and 11 patients spontaneous (S) GNBM; the mean age of the former was 42 +/- 16 years and of the latter 56 +/- 14 years (p less than 0.05).