Introduction[edit | edit source]
Tabes dorsalis is a slowly progressive degenerative disorder of the dorsal column and dorsal root of the spinal cord. Tabes dorsalis is caused by demyelination as a result of an untreated syphilis infection caused by Treponema pallidum. Treponema pallidum infection, if left untreated or partially treated, can lead to late neurosyphilis which has two forms, general paresis (also known as "syphilitic dementia," "dementia paralytica" or "paretic neurosyphilis") and tabes dorsalis (also known as "locomotor ataxia").  Neurosyphilis may be a more common and more aggressive complication of syphilis in those infected with HIV. It is more common in males than in females.
Clinically Relevant Anatomy
[edit | edit source]
Sensory information is transmitted through the dorsal (posterior) column of the spinal cord and through the medial lemniscus in the brainstem. The dorsal column-medial lemniscal pathway is responsible for conveying sensations of vibration, proprioception and fine touch (tactile sensation).
Pathological Process[edit | edit source]
Treponemes are spirochetes, which are thin, delicate, helically coiled organisms measuring 5-20 µm in length. Treponema pallidum can be transferred vertically from mother to fetus and through sexual intercourse. Tabes dorsalis is a parenchymatous form of neurosyphilis and typically has a latency of 15–30 years from the time of infection. The disease usually involves three phases. The primary infection follows the inoculation of an individual with about 500–1000 bacteria. Within 36 hours, these replicate and result in a painless ulceration called a chancre. These typically occur in the genital areas. After 2–6 weeks the second stage of the disease continues, with wide infiltration throughout the body and nervous system. Afterward, during the latent stage of disease, patients are frequently asymptomatic for many years. About 10% of patients with untreated syphilis develop neurological symptoms called neurosyphilis, or tabes dorsalis, 10–15 years later. 
Clinical Presentation[edit | edit source]
The neurologic presentation is one of ongoing loss of pain sensation, loss of peripheral reflexes, impairment of vibration and position senses, and progressive ataxia. The earliest stages of neurosyphilis involve inflammation of the meninges presenting with headache, nausea, vomiting, and, occasionally, seizures. There may be chronic destructive changes in the large joints of the affected limbs in far-advanced cases (i.e., Charcot's joints). Incontinence of the bladder and impotence are common. Sudden and severely painful crises of uncertain origin are a characteristic part of the syndrome.
Diagnostic Procedure[edit | edit source]
Diagnosis of syphilis is made using two types of tests: (1) non-treponemal serum screening tests, such as the rapid plasma reagin (RPR) and Venereal Disease Research Laboratory (VDRL) test; and (2) treponemal-specific tests such as the fluorescent treponemal antibody absorption test (FTA-ABS), T. pallidum particle agglutination assay (TP-PA), and microhemagglutination test for antibodies to T. pallidum (MHA-TP). Since Treponema pallidum cannot be grown in a culture medium, serology and CSF examination are the mainstays for diagnosis. In patients with suspected neurosyphilis and stroke, a negative CSF FTA-ABS effectively rules out the disease and a positive VDRL effectively confirms it. In patients with a positive CSF FTA-ABS and a negative VDRL, CSF protein and cell count and clinical judgment might be needed to decide on the treatment.
Management / Interventions[edit | edit source]
Medical treatment[edit | edit source]
Medical treatment involves penicillin, administered intravenously. Opiates, valproate and carbamazepine are some of the analgesics used in treating pain associated with Tabes dorsalis.
Physiotherapy management[edit | edit source]
- Improve coordination
- Improve muscle strength.
- Improve muscle endurance.
- Improve balance.
- Improve posture.
- Retrain normal movement pattern.
- Educate the patient about sensory loss and precautions to be taken.
Preventive management[edit | edit source]
Preventive drug therapy should be given to those who have sexual contact with an individual with syphilis.
Differential Diagnosis[edit | edit source]
The differential diagnostic possibilities of neurosyphilis are broad, given the protean manifestations of its various forms and stages. Some of the conditions that present similar clinical features as Tabes dorsalis include:
- Vascular Disease Myelopathy
- Post infectious Demyelination
- Hereditary and Other Demyelinating Disorders
- Spinal Tumors Miscellaneous Spinal Cord Myelopathy
- Non-Syphilitic Argyll Robertson Pupil
- Acute meningitis
Prognosis[edit | edit source]
Prognosis is good after treatment, but Tabes dorsalis may lead to paralysis, blindness and dementia if left untreated.
References[edit | edit source]
- Bhandari J, Thada PK, Ratzan RM. Tabes Dorsalis.
- Johnson RT, Griffin JW, McArthur JC, editors. Current therapy in neurologic disease. Elsevier Health Sciences; 2006.
- Learning in Ten. Tabes Dorsalis. Available from:https://www.youtube.com/watch?v=yYd4zeDqh94
- Cintron R, Pachner AR. Spirochetal diseases of the nervous system. Current opinion in neurology. 1994 Jun 1;7(3):217-22.
- Fitzgerald TJ. Pathogenesis and immunology of Treponema pallidum. Annual Reviews in Microbiology. 1981 Oct;35(1):29-54.
- Daroff RB, Aminoff MJ. Encyclopedia of the neurological sciences. Academic press; 2014 Apr 29.
- Sontheimer H. Diseases of the nervous system. Academic Press; 2015 Mar 6.
- Knudsen RP. Neurosyphilis: overview of syphilis of the CNS. Medscape Reference. 2011.
- Hook EW. Goldman's Cecil Medicine (Twenty Fourth Edition), 2012.
- Cucchiara B, Price RS, editors. Decision-Making in Adult Neurology, E-Book. Elsevier Health Sciences; 2020 Sep 16.
- Gutierrez J, Katan M, Elkind MS. Collagen vascular and infectious diseases. InStroke 2016 Jan 1 (pp. 619-631). Elsevier.