Infections and other inflammatory conditions.

The etiology of cerebral palsy and other related perinatal brain injuries is poorly understood. Infections of the central nervous system are rare but important causes of neurodisability. Recent evidence suggests that infections and other inflammatory conditions apparently limited to the placenta are also associated with an increased risk of neurologic impairment. A major hypothesis to explain this connection is that cytokines, activated inflammatory cells, and other mediators of the innate immune response are released into the fetal circulation where they can directly or indirectly affect the development or integrity of the central nervous system. This review surveys the organisms, mediators, and placental lesions that have been associated with perinatal brain injury.