Tabes Dorsalis Mnemonic:
Tabes dorsalis, also known as syphilitic myelopathy, is a slow degeneration (specifically, demyelination) of the sensory neurons that carry afferent information. The degenerating nerves are in the dorsal columns (posterior columns) of the spinal cord (the portion closest to the back of the body) and carry information that help maintain a person’s sense of position (proprioception), vibration, and discriminative touch.
Tabes dorsalis is caused by demyelination secondary to an untreated syphilis infection.
Symptoms may not appear for some decades after the initial infection and include: weakness, diminished reflexes, paresthesias (shooting and burning pains, pricking sensations, and formication), hypoesthesias (abnormally diminished cutaneous, especially tactile, sensory modalities), tabetic gait (locomotor ataxia), progressive degeneration of the joints (Charcot Joints), loss of coordination, episodes of intense pain and disturbed sensation (including glossodynia), personality changes, urinary incontinence, dementia, deafness, visual impairment, positive Romberg’s test, and impaired response to light (Argyll Robertson pupil). The skeletal musculature is hypotonic due to destruction of the sensory limb of the spindle reflex. The deep tendon reflexes are also diminished or absent; for example, the “knee jerk” or patellar reflex may be lacking (Westphal’s sign). A complication of tabes dorsalis can be transient neuralgic paroxysmal pain affecting the eyes and the ophthalmic areas, previously called “Pel’s crises” after Dutch physician P.K. Pel. Now more commonly called “tabetic ocular crises,” an attack is characterized by sudden, intense ocular pain, lacrimation and photophobia.
“Tabes dorsalgia” is a related back pain.
“Tabetic gait” is a characteristic high-stepping gait of untreated syphilis where the patient’s feet slap the ground as they strike the floor due to loss of proprioception.
Penicillin, administered intravenously, is the treatment of choice. Associated pain can be treated with opiates, valproate, or carbamazepine. Patients may also require physical therapy to deal with muscle wasting and weakness. Preventive treatment for those who come into sexual contact with an individual with syphilis is important.