化脓性脑膜炎(英文)初步.pptVIP

Circulation of cerebrospinal fluid(CSF) * * Purulent Meningitis in Children Jiang Li Department of Neurology Children’s Hospital Chongqing University of Medical Sciences Acute infection of central nervous system(CNS). 90% of cases occur in the age of 1mo-5yr. The inflammation of meninges caused by various bacteria.Common features in clinical practices include: fever, increased intracranial pressure, meningeal irritation. ? One of the most potentially serious infections, associated with high mortality (about 10%) and morbidity. Purulent Meningitis Etiology 1.1 Pathogens: Main pathogens: Neissria meningitidis, streptoccus pneumoniae, Haemophilus influenzae. (2/3 of purulent meningitis are caused by these pathogens) Pathogens in special populations (neonate 3mo infants , malnutrition, immunodeficiency): gramnegative enteric bacilli, group B streptococci, staphlococcus aureus 1.2 Major risk factors for meningitis Immature immunologic function and attenuated immunologic response to pathogens ? Low level of immunoglobulin, defects of complement and properdin system ? Immature or impaired blood-brain-barrier (BBB) ? Immature BBB function: maturation at about 1yr ? Impaired BBB: Congenial or acquired defects across mucocutaneous barrier 1.3 Access of bacteria invasion ? Typical access---hematogenous dissemination ? Bacteria colonizing the mucous membranes of the nasopharynx ?invasion into local tissue ? bacteremia ? hematogenous seeding to the subarachnoid space ? Mode of transmission: Person to person contact through respiratory tract secretions or droplets Bacteria spread to the meninges directly: through anatomic defects in the skull or head trauma Invasion from parameningeal organs: such as paranasal sinuses or middle ear Access of bacteria invasion 2. Pathology Structure of meninges Characterized by leptomeningeal and