A clinical study of new cases of parenchymal neurosyphilis: has tabes dorsalis disappeared or been missed?

Tabes dorsalis (TD) was documented as the most common parenchymal neurosyphilis, but its incidence dramatically declined in the antibiotic era. Syphilis has resurged on the China mainland since the 1980s. In recent years, physicians have been reporting parenchymal neurosyphilis, and the overwhelming majority was general paresis, but this was not the case in the authors' hospital. To make clear the real situation of parenchymal neurosyphilis in the authors' hospital, a retrospective review was carried out of the records of patients during 2009-2012. Overrepresented clinical new cases of tabetic and paretic parenchymal neurosyphilis were collected. Clinical characteristics, neuroimaging, laboratory data, and responses to penicillin were analyzed in two groups. The efficiency of two current criteria based on CSF antibodies tests was inspected. In the 43 cases with positive serum rapid plasma reagin (RPR) and TPPA tests, 18 patients met the criteria of this study: 11 presented with symptoms of general paresis, and seven had typical presentations of TD. There were statistical differences in serum RPR titers, CSF RPR, white blood cell count, and TP between the paretic and tabetic groups. The response to penicillin was relatively poor in TD. The efficiency of two current criteria was lower in the diagnosis of TD. TD was not uncommon in our area. Its clinical features remained typical, but underdiagnosis with CSF-based criteria and a decreased response to penicillin were prominent issues.