| Transcript |
All right today we're going to be talking about syphilis in neuro-ophthalmology, and as you know, syphilis has been around since forever. And it has three stages: the primary, the secondary and the tertiary stage. It can also go latent during any of these periods of time, and it can become neurosyphilis. And ocular syphilis equals pretty much neurosyphilis and the reason that's important is because the treatment of neurosyphilis requires intravenous pencillin rather than intramuscular or oral and we would do a lumbar puncture with CSF analysis to make sure that we can follow the cell counts and the protein and the CSF VDRLs after treatment with intravenous penicillin. The primary lesion is the chancre. We don't see that in ophthalmology. Usually it's the secondary lesion that we see, which is the uveitis that might be characterized by a bilateral and symmetric maculopapular erythematous rash on the palms and soles. And for neuro-op tertiary syphilis, which could endure years or even decades after the initial exposure so we should be thinking about syphilis in neuro-ophthalmology, and any unexplained neuro-ophthalmic finding, regardless of age, regardless of gender, regardless of sexual preference because it's a stage disease that can occur any time in a person's life and the primary exposure could be years ago because the disease can go latent with no symptoms whatsoever. And so when should you be thinking about syphilis? Anytime you have swelling: "itis" so conjunctivitis, episcleritis, scleritis, anterior uveitis, intermediate uveitis, posterior uveitis, chorioretinitis, optic neuritis, meningitis, meningoencephalitis. All of these unexplained swellings: swollen optic nerve, swollen retina, swollen lid, anything that is "itis," we really should be thinking about syphilis in the differential. And in the tertiary stage it might just show up as a latent; that is there is no "itis," they just have optic atrophy. And so for neuro-ophthalmology we really should be thinking about syphilis in every patient with an unexplained neuro-ophthalmic finding, whether that's pupil, lid, afferent side, efferent side, diplopia, pale nerve, swollen nerve or infectious neuroretinitis, it doesn't matter. Syphilis could always be in the differential diagnosis. And so the testing, we need to have a treponemal test and the treponemal tests usually have a "T" in them. So MHA-TP (micro hemagglutination for Treponema pallidum), FTA-ABS (the fluorescent treponemal antibody) or the syphilis Treponema pallidum IgG: these are all treponemal tests. We also need to have the non-treponemal tests and the non-treponemal tests don't have a "T." So that's RPR and VDRL but you don't need both, you just need one treponemal tests and one non-treponemal test. And so in our hospital we've gone to the reverse algorithm, which means we're going to do the treponemal tests first. If it's negative, you can stop. If it's positive, we do a simultaneous non-treponemal test, so RPR or VDRL. If both are positive, so both are positive that's easy you have the disease. It's also easy if both the treponemal and the non-treponemal are negative, then you don't have the disease. If the treponemal test is negative but the non-treponemal test is positive, like the RPR, then we'll repeat the treponemal test, a different treponemal test, and if two treponemal tests are negative, then this positive non-treponemal test RPR is probably a false positive. And the hardest one is if the treponemal test is positive but the RPR or the VDRL is negative, and that has two possibilities: either you had syphilis before, because once the titer is positive for the treponemal antibody, it's positive for life regardless of treatment. And so if you have that scenario, they have to produce documentation that they received adequate dosing of penicillin, so FTA positive RPR negative with the piece of paper that shows they had syphilis treatment with penicillin, you can stop. But if they cannot produce this paper, then probably we would repeat a treponemal test, and if two treponemal tests are positive and the RPR is negative, but the clinical scenario still suggests syphilis we would treat that and evaluate that as if it's neurosyphilis. That'd mean a lumbar puncture and we would still empirically consider treating that person with penicillin. So you should be thinking about syphilis in every patient. Some presentations are more typical but it's every unexplained neuro-op-the most typical in the literature are the Argyll Robertson pupil, which is a pupil that doesn't react to light but does react to near. It's typically small and irregular. It's bilateral, but even a bilateral tonic pupil, what looks like Adie's tonic pupil to you should still have the syphilis serology. In the eye complaints of optic atrophy, optic disc edema and optic disc edema with a macular star figure, which is infectious neuroretinitis, you should be testing for syphilis in those patients, the star figure patients, and if we have chorioretinitis, or in particular, acute syphilitic placoid or pigment epitheliopathy or placoid chorioretinitis, those things have less wide differential diagnoses and you should always be testing those patients for syphilis. And finally we want to test and treat for the comorbidities. Anybody who has a sexually transmitted disorder we want to test them for the other sexually transmitted disorders. At the presence of HIV not only modulates the risk but also changes the treatment and the follow-up because they are immuno-suppressed. So HIV patients we'd like to know if they're HIV positive; do they have cd4 counts and viral loads, etc. So, in summary you should be thinking about syphilis in every patient who has an unexplained neuro-ophthalmic finding. Even though the classic findings are Argyll Robertson pupil, the infectious neuroretinitis and acute syphilitic placoid chorioretinopathy, you should be thinking about syphilis in every patient, regardless of age, regardless of gender, and regardless of sexual history. And you got to know how to order both the treponemal and the non-treponemal tests for syphilis and how to interpret them in neuro-op. |
