The Pathogenesis of Meningitis

EVIDENCE has accumulated which suggests that gram-negative endotoxin may act on elements of the nervous system to produce significant systemic pathology.¹⁻⁷Penner and Bernheim⁴demonstrated that ulcerative lesions of the gastrointestinal tract, which are present in systemic canine endotoxin shock, appear after the introduction of very small doses ofShigellaendotoxin into the third ventricle. Such doses would be completely ineffective if given systemically.⁴Palmerio et al⁵have confirmed these observations in the dog and rabbit withEscherichia coliendotoxin. Kass et al⁷observed that the lethal dose ofE coliendotoxin is smaller when injected into the carotid artery of rats and that endotoxin lethality can be eliminated by posterior hypothalamic ablation. We have previously demonstrated that small doses ofE coliendotoxin placed into the cisterna magna or lateral ventricle of dogs can produce a variety of systemic pathologic lesions associated