In syphilis, is a lumbar puncture performed before or after a Venereal Disease Research Laboratory (VDRL) test?

From the Guidelines

In syphilis evaluation, a lumbar puncture is typically performed after a positive VDRL or other serologic tests for syphilis. The initial screening for syphilis involves blood tests such as VDRL, RPR (Rapid Plasma Reagin), or treponemal-specific tests like FTA-ABS or TP-PA. If these blood tests are positive, a lumbar puncture may then be indicated to evaluate for neurosyphilis, particularly in patients with neurological symptoms, late latent syphilis, tertiary syphilis, HIV co-infection, or treatment failure, as suggested by the guidelines 1. During the lumbar puncture, cerebrospinal fluid (CSF) is collected and tested with CSF-VDRL, which is specific but not very sensitive for neurosyphilis. Additional CSF analysis includes cell count, protein levels, and sometimes CSF-FTA-ABS. This sequential approach is logical because performing invasive lumbar punctures is unnecessary in patients who don't have serologic evidence of syphilis infection. Some key points to consider when deciding on the timing of a lumbar puncture include:

• The presence of neurologic or ocular symptoms or signs, which would necessitate a lumbar puncture, as indicated by the guidelines 1
• The stage of syphilis, with late latent syphilis (of 11 year duration or more) being an indication for lumbar puncture, according to the guidelines 1
• The results of CSF analysis guide treatment decisions, as neurosyphilis requires more aggressive therapy with intravenous penicillin G. The most recent and highest quality study, although from 2009, still provides relevant guidance on this issue, emphasizing the importance of a lumbar puncture in specific clinical scenarios 1.

From the Research

Lumbar Puncture and VDRL in Syphilis Diagnosis

• The order of performing a lumbar puncture (LP) and Venereal Disease Research Laboratory (VDRL) test in syphilis diagnosis is not explicitly stated in the provided studies.
• However, the studies suggest that LP is performed to rule out neurosyphilis, and VDRL is used as a diagnostic tool to confirm the presence of syphilis 2, 3, 4, 5.
• In the diagnosis of neurosyphilis, a reactive CSF-VDRL test result is considered a key indicator 4, 5.
• The decision to perform an LP is often based on the presence of neurologic symptoms, such as headache, visual symptoms, and gait incoordination 4, 5.
• The VDRL test is typically performed before or concurrently with the LP, as it is used to confirm the diagnosis of syphilis and to monitor the effectiveness of treatment 2, 3.

Diagnostic Criteria for Neurosyphilis

• Neurosyphilis is defined by a reactive CSF-VDRL test result and/or a CSF white blood cell (WBC) count of >20 cells/μl 4.
• The diagnosis of neurosyphilis can be challenging, especially in HIV-infected patients, and the criteria for deciding when to perform an LP are controversial 4, 6.
• The studies suggest that LP should be performed in patients with syphilis who have neurologic symptoms, regardless of their HIV status 5, 6.

Treatment and Management of Neurosyphilis

• The treatment of neurosyphilis typically involves parenterally administered penicillin G, which is considered the first-line therapy for all stages of syphilis 2, 3.
• Alternative regimens, such as doxycycline and ceftriaxone, may be used in patients who are allergic to penicillin or have other contraindications 2, 3.
• The management of neurosyphilis requires close monitoring of CSF parameters and serial LPs to ensure adequate treatment 2, 6.