From the Guidelines
Syphilis FTS csf testing is not the preferred method for diagnosing neurosyphilis, instead, CSF-VDRL is recommended. When evaluating for neurosyphilis, a lumbar puncture should be performed to obtain CSF, which should be tested with CSF-VDRL, along with cell count, protein, and glucose measurements 1. Treponemal tests like FTS detect antibodies specific to Treponema pallidum but cannot distinguish between active and treated infections, making them less useful in CSF.
Key Points to Consider
- A diagnosis of neurosyphilis typically requires both clinical symptoms (such as cognitive changes, cranial nerve abnormalities, or meningitis) and laboratory evidence (positive CSF-VDRL or elevated CSF white blood cells with elevated protein) 1.
- CSF examination should be performed in persons with neurologic or ocular signs or symptoms, active tertiary syphilis, and treatment failure, as well as in HIV-infected persons with late-latent syphilis, including those with syphilis of unknown duration 1.
- Treatment for neurosyphilis consists of aqueous crystalline penicillin G 18-24 million units daily, administered as 3-4 million units IV every 4 hours for 10-14 days, or procaine penicillin 2.4 million units IM daily plus probenecid 500 mg orally four times daily for 10-14 days for patients who cannot receive IV therapy.
Additional Considerations
- Response to therapy of late-latent syphilis should be monitored using nontreponemal serologic tests at 6,12,18, and 24 months to ensure at least a fourfold decline in titer 1.
- CSF examination should be repeated at 6 months after completion of therapy, and if clinical symptoms develop or nontreponemal titers rise fourfold, a repeat CSF examination should be performed and treatment administered accordingly 1.
From the Research
Syphilis FTS CSF
- The diagnosis of neurosyphilis can be challenging, and the use of cerebrospinal fluid (CSF) analysis is crucial in confirming the diagnosis 2.
- CSF parameters such as CSF-VDRL or CSF-PCR tests can help diagnose neurosyphilis, and a positive result can indicate the presence of the disease 3.
- The treatment of neurosyphilis typically involves the use of penicillin G, but ceftriaxone may be a reasonable alternative therapy 3, 4.
- The use of metagenomic next-generation sequencing (mNGS) can also be valuable in diagnosing neurosyphilis, especially in cases where routine CSF analysis is inconclusive 5.
- It is essential to have a high index of suspicion and awareness of the variable clinical presentations of neurosyphilis to ensure timely and accurate diagnosis 4.
- Coinfection with HIV can further complicate the diagnosis and management of neurosyphilis, and clinicians must be aware of the recent changes in the epidemiology of syphilis 6.
CSF Analysis
- CSF analysis is a critical component of neurosyphilis diagnosis, and the results can help guide treatment decisions 2.
- The CSF Venereal Disease Research Laboratory (VDRL) test is a mainstay of diagnostic testing for neurosyphilis, but using a higher titer cutoff for the Treponema pallidum particle agglutination assay (TPPA) from the CSF may improve the utility of the TPPA as a supporting criterion for the diagnosis of neurosyphilis 4.
- The interpretation of CSF findings can be challenging, and clinicians must be aware of the limitations and controversies related to neurosyphilis diagnosis and treatment 6.
Treatment
- Penicillin G is the treatment of choice for neurosyphilis, but ceftriaxone may be a reasonable alternative therapy, especially in cases where patients are allergic to penicillin or have other contraindications 3, 4.
- The use of ceftriaxone has been shown to be effective in treating neurosyphilis, with a shorter length of hospital stay compared to benzylpenicillin 3.
- Empirical neurosyphilis treatment should be considered upfront in patients with a high pre-test probability of the diagnosis, especially in cases where CSF analysis is inconclusive or unavailable 2.