THE USEFULNESS OF CEREBROSPINAL-FLUID TESTS FOR NEUROSYPHILIS

To determine the usefulness of cerebrospinal fluid (CSF) tests for syp hilis at a large academic hospital, clinical and laboratory data on 64 4 patients in whom such testing was requested over a 12-month period w ere analysed. In 198 cases (31%) the Treponema pallidum haemagglutinat ion (TPHA) screening test could not be performed because of insufficie nt fluid. Thirty-eight of the remaining patients were diagnosed as hav ing active neurosyphilis. Examination of 22 files of patients who had a positive TPHA and fluorescent treponemal antibody absorption (FTA-Ab s) test together with a negative CSF Venereal Disease Research Laborat ory (VDRL) test revealed that other CSF measures indicating disease ac tivity (CSF protein, cells or IgG index) were not utilised optimally. In 10 (45%) of these patients neurosyphilis was not diagnosed despite either abnormal or incomplete CSF biochemical analysis, indicating tha t if the CSF VDRL is used as the sole marker for disease activity, som e cases of neurosyphilis are likely to be missed.