Pathology o 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 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. Pathology