<unk>  refers to infection of the central nervous system in a patient with syphilis. In the era of modern antibiotics the majority of<unk>  cases have been reported in HIV-infected patients. Meningitis is the most common neurological presentation in early syphilis. Tertiary syphilis symptoms are exclusively<unk> , though<unk>  may occur at any stage of infection. To diagnose<unk> , patients undergo a lumbar puncture to obtain cerebrospinal fluid (CSF) for analysis. The CSF is tested for antibodies for specific Treponema pallidum antigens. The preferred test is the VDRL test, which is sometimes supplemented by fluorescent treponemal antibody absorption test (FTA-ABS). Historically, the disease was studied under the Tuskegee study, a notable example of unethical human experimentation. The study was done on approximately 400 African-American men with untreated syphilis who were followed from 1932 to 1972 and compared to approximately 200 men without syphilis. The study began without informed consent of the subjects and was continued by the United States Public Health Service until 1972. The researchers failed to notify and withheld treatment for patients despite knowing penicillin was found as an effective cure for<unk> . After four years of follow up,<unk>  was identified in 26.1% of patients vs. 2.5% of controls. After 20 years of followup, 14% showed signs of<unk>  and 40% had died from other causes.
Neurosyphilis
Syphilis
Mumps
Chickenpox
Leprosy
Smallpox
Rubella
Rickettsialpox