Tabes Dorsalis

Excerpt

Tabes dorsalis, also known as locomotor ataxia, is a slowly progressive and rare degenerative parenchymatous disease of the dorsal columns and dorsal roots of the spinal cord. This condition is caused by central nervous system (CNS) infection with Treponema pallidum subspecies pallidum—the bacterium responsible for sexually transmitted syphilis. Tabes dorsalis, along with general paresis, is considered tertiary or late neurosyphilis and distinguishes itself by exhibiting the lengthiest latent period among all forms of neurosyphilis, typically averaging around 20 years from primary infection to symptom onset, though occasionally early onset is reported. While prevalent in the pre-antibiotic era, tabes dorsalis has become rare.

Clinically, patients with tabes dorsalis often present with symptoms such as sensory ataxia and lancinating pains, characterized by sudden and intense stabbing sensations in the limbs, back, or face, which may persist for minutes to days. Less frequent symptoms include paresthesia and gastric crises, marked by recurrent bouts of severe epigastric pain, nausea, and vomiting, along with early-onset bladder dysfunction leading to urinary retention and overflow incontinence. Pupillary irregularities, notably the Argyll Robertson pupil, are characteristic features associated with tabes dorsalis. Other neurological findings encompass absent lower extremity reflexes, impaired vibratory and positional sensation, deficits in touch, pain, and optic function. Chronic destructive changes in the large joints of the affected limbs may occur in advanced cases.

Diagnosing neurosyphilis can be challenging, requiring clinicians to maintain a high index of suspicion. However, early recognition and appropriate treatment can result in positive clinical outcomes.