Tabes dorsalis is a late consequence of neurosyphilis, characterized by the slow degeneration of the neural tracts primarily in the dorsal root ganglia of the spinal cord. These patients have lancinating nerve root pain which is aggravated by coughing, and features of sensory ataxia with ocular involvement.
Signs and symptoms may not appear for decades after the initial infection and include weakness, diminished reflexes, paresthesias, hypoesthesias, tabetic gait, progressive degeneration of the joints, loss of coordination, episodes of intense pain and disturbed sensation, personality changes, urinary incontinence, dementia, deafness, visual impairment, positive Romberg's test, and impaired response to light. 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. 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 eye pain, tearing of the eyes and sensitivity to light. "Tabes dorsalgia" is a related lancinating back pain. "Tabetic gait" is a characteristic ataxic gait of untreated syphilis where the person's feet slap the ground as they strike the floor due to loss of proprioception. In daylight the person can avoid some unsteadiness by watching their own feet.
Cause
Tabes dorsalis is caused by demyelination by advanced syphilis infection, when the primary infection by the causative spirochetebacterium, Treponema pallidum, is left untreated for an extended period of time.. The spirochete invades large myelinated fibers, leading to the involvement of the dorsal columnmedial leminiscus pathway rather than the spinothalamic tract.
Left untreated, tabes dorsalis can lead to paralysis, dementia, and blindness. Existing nerve damage cannot be reversed.
Epidemiology
The disease is more frequent in males than in females. Onset is commonly during mid-life. The incidence of tabes dorsalis is rising, in part due to co-associated HIV infection.
History
Although there were earlier clinical accounts of this disease, and descriptions and illustrations of the posterior columns of the spinal cord, it was the Berlin neurologist Romberg whose account became the classical textbook description, first published in German and later translated into English. Sir Arthur Conan Doyle, author of the Sherlock Holmes stories, completed his doctorate on tabes dorsalis in 1885.
Notable patients
German storywriter E.T.A. Hoffmann appears to have suffered and died from tabes dorsalis.
