Molecular pathophysiology of bacterial meningitis: current concepts and therapeutic implications

Bacterial meningitis, an infection of the membranes covering the brain and spinal cord, is a condition which in children is fatal in 3 to 7 percent of patients. This mortality rises to 30 percent among adults and newborns. One third of the patients surviving bacterial meningitis develop neurologic complications. These neurologic complications of meningitis may be caused by abnormal changes in molecular function. The currently identified elements of the meningeal inflammatory network, as well as experimental models and possible treatments are described. In addition, the results of clinical trials using dexamethasone to treat bacterial meningitis are reported. There are three components of bacteria which affect the strength of the organism: the capsule which surrounds the cell, the wall of the cell, and the lipopolysaccharide attached to the outer membrane of the cell. Recently, cytokines, chemicals secreted in response to the presence of bacteria, have been implicated as mediators in the inflammatory process. Interleukin-1, a cytokine, may be responsible for the body's response to bacterial infection, such as elevation of body temperature and white blood cell count. This new understanding of the role of mediators in infection may provide a new approach to treatment. Recent clinical trials of dexamethasone have shown that neurological complications occurred significantly less often in patients treated with dexamethasone than those receiving a placebo. Side effects of dexamethasone are infrequent. It is suggested that dexamethasone be considered to treat bacterial meningitis in children over the age of 2 months. Also, this treatment should be begun prior to or at the same time as the initial dose of intravenous antibiotic. (Consumer Summary produced by Reliance Medical Information, Inc.)