化脓性脑膜炎60566 PPT.ppt

Purulent Meningitis Purpose and demand: To familiarize the pathogeny of purulent meningitis. To understand the mechanism and pathology change. To grasp the clinical manifestation,diagnosis,differential diagnosis and treatment. To self-study the accessory examination of neural system. Contents Induction Etiology pathogenesis Manifestations Complications Laboratory findings Diagnosis differential diagnosis Treatment prevention Introduction Acute infection of central nervous system(CNS). 75% of cases occur in the age of 2yr. The inflammation of meninges caused by various bacteria.Common features in clinical practices include: fever,headache,vomit, convulsions, disturbance of consciousness,increased intracranial pressure, meningeal irritation. One of the most potentially serious infections, associated with high mortality (about 10%) and morbidity. Etiology 1. Pathogens: Main pathogens: Neissria meningitidis, streptoccus pneumoniae, Haemophilus influenzae. 2/3 of purulent meningitis are caused by these pathogens Access of bacteria invasion Typical access---hematogenous dissemination ? Bacteria colonizing the mucous membranes of the nasopharynx ?invasion into local tissue ? bacteremia ? through BBS ?mainly effect on arachnoid and leptomeninges ? Mode of transmission: Person to person contact through respiratory tract secretions or droplets Access of bacteria invasion Invasion from parameningeal organs:such as paranasal sinuses or middle ear Bacteria spread to the meninges directly: through anatomic defects in the skull or head trauma Structure of meninges Pathology Characterized by leptomeningeal and perivascular infiltration with polymorphonuclear leukocytes and an inflammatory exudate. Exudate which may be distributed from convexity of brain to basal region of cranium. Exudate is more thickness due to streptococcus pneumoniae than other pathogens. Cli