The effect of streptomycin on the lesions of tuberculous meningitis.

The extensive therapeutic use of streptomycin in tuberculous meningitis has necessitated the study of the effects of this antibiotic on the pathological processes of this disease. The conclusions of investigators concerning the alterations in the pathological picture in treated cases vary. Smith, Vollum and Cairns’ found prolongation of the clinical course of the meningitis, but several of their cases exhibited complications In the form of hydrocephalus, old cerebral infarcts secondary to obstruction of small vessels, hypothalamic disturbances, and spinal fluid block. Of the 10 cases reported by Chiarl,2 some presented the lesions typical of untreated meningitis, others showed heavy white thickening of the meninges, and in one there was nodular meningeal calcification; severe hydrocephalus was usual. Organization of the exudate with meningeal scarring was typical, and obliterative endarteritis was an important finding. The observations of Cornil and collaborators3 were similar. The case of Varga and Blasi4 showed a fibroplastic basal exudate and hydrocephalus. Renth5 noted arteritic lesions, including overgrowth of endothelium and obstruction of the lumen. Doniach6 compared the vessels of 20 treated cases with those of untreated ones and consistently found productive arterial changes in those patients who had had a clinical course which was prolonged by the use of streptomycin. Fazio7 ascribed the productive vascular reaction to the evolution of a chronic form of the disease. Baggenstoss, Feldman and Hinshawt believed that streptomycin exerted an inhibitory or curative effect in meningeal tuberculosis. On the other hand, each of the three cases reported by Wright and Rees9 showed hydrocephalus and a thick soft basal exudate that contained tubercie bacilli. Montgomery,’#{176} in a study of six cases, observed the persistence of progressive meningeal lesions while systemic tuberculous foci gave evidence of regression. Bornsteln” believed that streptomycin was without effect on meningitis, but was responsible for healing of coexistent miliary tuberculosis. We have had the opportunity to examine the brains from 10 fatal cases of tuberculous meningitis. Streptomycin had been ad-