Neurosyphilis has several forms: Asymptomatic neurosyphilis Meningovascular neurosyphilis Parenchymatous neurosyphilis Tabes dorsalis Asymptomatic neurosyphilis causes mild meningitis in about 15% of patients originally diagnosed as having latent syphilis, in 25 to 40% of those with secondary syphilis, in 12% of those with cardiovascular syphilis, and in 5% of those with benign tertiary syphilis.