It is not surprising that, when so fatal a disease as syphilis of the central nervous system is attacked with a drug so powerful as arsenic, serious results should now and then occur. The gravity of the disease and its general tendency toward fatality, however, fully justify the risk in view of the beneficial results so commonly observed. Only a few cases of myelitis have been so far recorded, although it is probable that a considerable number of unrecognized cases have occurred or been reported under more general captions. Perhaps the most common neurotoxicologic result of the administration of salvarsan has been a hemorrhagic encephalitis. In some cases this has been verified by necropsy and histologic examination. In some of the cases, however, which clinically looked like encephalitis nothing was found histologically in the central nervous system.
The following reports are brief outlines of the few cases recorded, together with
McCASKEY GW. SALVARSAN AND NEOSALVARSAN MYELITISREPORT OF A FATAL CASE. JAMA. 1917;LXIX(23):1960–1962. doi:10.1001/jama.1917.02590500042010