Typical case of Tabes Dorsalis and Argyll Robertson pupils

Dr Chinar Osman, at the University of Southampton, Southampton, United Kingdom and colleagues have reported a typical case of Tabes Dorsalis and Argyll Robertson Pupils a manifestation of neurosyphilis. The case has appeared in NEJM.

Tabes dorsalis is a form of neurosyphilis with a slow demyelination of the neural tracts primarily in the dorsal columns (posterior columns) of the spinal cord and dorsal roots. These nerves normally help maintain a person's sense of position (proprioception), vibration, and discriminative touch. Along with Argyll Robertson pupils, the condition is associated with ataxia and loss of proprioception. Left untreated, tabes dorsalis can lead to paralysis, dementia, and blindness. Moreover, existing nerve damage cannot be reversed.

According to history, a 47-year-old man a known case of HIV infection presented with an 8-month history of severe paroxysmal shooting pains in his legs, progressive difficulty in walking, tinnitus, and urinary incontinence. He was on antiretroviral therapy and had a fully suppressed HIV viral load and a CD4+ count of 400 cells per cubic millimetre.

Courtesy NEJM

On examination, the patient demonstrated an Argyll Robertson pupils, which are nonreactive to bright light but briskly constrict when focusing on a near object. MRI revealed high signal changes in the dorsal columns of the thoracic spine, and samples of blood and cerebrospinal fluid were positive for syphilis VDRL testing and Treponema pallidum particle agglutination assay.
The patient was treated with intravenous penicillin for 14 days, and gabapentin was started for the neuropathic leg pains.

After treatment, the patient’s symptoms and mobility slowly improved, although the shooting pains in his legs have continued despite pharmacotherapy. The serum VDRL level fell appropriately, and the result on VDRL testing of the cerebrospinal fluid was negative.