CerebrospinalFluid lgG and 1gMIndexesas Indicatorsof Active Neurosyphilis

Serological and non-serological tests were performed in matched samples of cerebrospinalfluidand serum from236 syphilitic patients. An increased lgG or lgM index, or both, was found about70 times more often in symptomatic neurosyphilis than in latent syphilis without involvement of the central nervous system. An increased Ig index, together with a cell count >5/4., was only found in symptomatic neurosyphilis. Although the numbers of data are small, we conclude that the igG and 1gM indexes are valuable tests in the diagnosis of syphiliticinvolvement of the central nervous system.