SHM Converge Scientific Abstract ePoster Gallery-A Case of Tabes Dorsalis Underlying Severe Sensorimotor Polyneuropathy

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This case describes a 51-year-old man with diabetes, CKD, hypertension, anemia, and progressive six-month worsening of bilateral leg weakness, sensory loss below the knees, gait instability, and absent reflexes. Initial evaluation showed severe sensorimotor polyneuropathy with mixed axonal and demyelinating features on EMG, elevated CSF protein, mild B12 deficiency with positive intrinsic factor antibody and elevated homocysteine, and poorly controlled diabetes. He was first treated as possible CIDP with IVIG, but clinicians later suspected a multifactorial neuropathy involving diabetes and B12 deficiency.<br /><br />A more detailed social history revealed prior unprotected sexual exposure while living in Southeast Asia, raising concern for tertiary syphilis. Although his VDRL was negative, a TP-PA treponemal test was positive, supporting neurosyphilis with tabes dorsalis. This case highlights that nontreponemal tests such as VDRL may be nonreactive in tertiary syphilis and are not sufficiently sensitive when clinical suspicion is high. Treponemal testing remains important because these antibodies often stay positive for years.<br /><br />The patient was treated with a two-week course of penicillin, high-dose vitamin B12 replacement, and tighter glucose control. At one-week follow-up, he was able to ambulate 75 feet with a walker, suggesting partial improvement.<br /><br />The main lesson is that tabes dorsalis, though rare, should be considered in patients with severe sensory ataxia or polyneuropathy, especially when routine workup is unrevealing. Thorough history taking and appropriate syphilis testing are essential to avoid missed neurosyphilis, which can lead to irreversible neurologic damage or paralysis.

Asset Subtitle

Taylor Seacor

Meta Tag

Author List Bhavin Patel, Taylor Seacor

Category Clinical Vignettes

Concept Tabes dorsalis

Concept Neurosyphilis

Concept Sensory Ataxia

Concept Treponemal Testing

Concept Multifactorial Neuropathy

Distinguished Non-Finalist

Presenter Organization UMass Chan Medical School

Presenting Author Taylor Seacor

Track Adult

Keywords

tabes dorsalis

neurosyphilis

polyneuropathy

diabetic neuropathy

vitamin B12 deficiency

VDRL negative

TP-PA positive

sensory ataxia

penicillin treatment

CIDP

Tabes dorsalis

Neurosyphilis

Sensory Ataxia

Treponemal Testing

Multifactorial Neuropathy