Tabes Dorsalis - Symptoms, Diagnosis, Treatment, and Prognosis

Introduction:

Tabes dorsalis is seen in patients who have developed syphilis and have not been treated in time. Syphilis is a bacterial infection transmitted through sexual contact and can cause serious life-threatening complications if left untreated. Tabes dorsalis is also known as progressive locomotor ataxia. Tabes dorsalis is a neurological complication of chronic (long-standing) untreated syphilis. The condition mainly affects the legs, and the symptoms may appear 20 to 25 years after an individual has acquired the disease. Tabes dorsalis is a highly progressive disorder that makes it impossible for an individual to walk unassisted and is highly debilitating.

What Is the Pathophysiology of Syphilis?

Syphilis is caused by the spirochete (spiral-shaped bacteria) Treponema Pallidum. Tabes dorsalis is also known as neurosyphilis. It affects the dorsal roots of the spinal cord. The dorsal (posterior) root of the spinal cord is one of the two roots that emerge from the spinal cord. Its function is to transmit sensory information from the central nervous system (brain and spinal cord) to the peripheral nervous system (nerves supply all other body parts except the brain and spinal cord). In this disorder, there is subsequent degeneration of the dorsal root of the spinal cord. Treponema pallidum is transmitted through direct contact with infected lesions. The bacteria can even penetrate intact skin. It can even be transmitted sexually and rarely through blood transfusions.

Pathophysiology of Syphilis

Treponema pallidum from the host gets transmitted to other individuals through intact mucous membranes or irritated skin. The bacteria then gets into the bloodstream and can spread to any body organ. In the chronic, tertiary stage of syphilis, the bacteria attacks the nervous system.

The symptoms of tabes dorsalis occur due to damage to the nervous system.

What Are the Symptoms of Tabes Dorsalis?

Tabes dorsalis is characterized by the following symptoms -

• Lightning pains are the initial symptom of this condition. Lightning pains are severe stabbing pains in the legs that last for a short period.

• A loss of tendon reflexes follows lightning pains. Tendon reflexes are involuntary contractions of the muscles in response to a stimulus.

• Abnormal muscle coordination leads to a spasmodic (unsteady) gait or uneven walk. Patients tend to walk with their legs spread far apart.

• Sensory deficits cause an inability of the individual to experience pain, difficulty in identifying the limb position, and sense temperature.

• Osteoarthritis usually involves the hip and knees and is known as Charcot's joints.

• Patients experience a loss in bladder control.

• Loss of sensations in the legs and feet may lead to severe foot ulcerations.

• Problems with the vision.

• Sexual dysfunction (problem with sexual function).

How Is Tabes Dorsalis Diagnosed?

The physician will perform a complete physical examination and check the nervous system signs.

• Neurological Examination - This can be carried out in the physician's office. Firstly the mental status of the patient is examined by checking how aware the patient is about the surroundings and responsiveness to external stimuli. The motor function, balance, and coordination of the patient are also assessed by giving different physical activities to the patient. A sensory examination is also carried out by exposing the patient to different temperatures and textures.

• Brain Imaging Scans - CT (computed tomography) and MRI (magnetic resonance imaging) scans of the head and neck are carried out to evaluate the brain and spinal cord to rule out other abnormalities.

• Syphilis Screening tests - The following tests are performed to confirm the diagnosis of syphilis -

1. Serum VDRL (Venereal Disease Research Laboratory) - This test does not identify the bacteria responsible for syphilis but identifies the antibodies produced by the body in response to the infection. These antibodies are like fighter cells that protect the body against invading microorganisms.

2. Serum RPR(Rapid Plasma Reagin) - This is a blood test performed on individuals suspected of syphilis. This test also identifies the antibodies produced by the body to diagnose an active infection in the body.

There is a high chance that the tests mentioned above may have a false-positive result. In such cases, additional antibody-specific tests may have to be performed to confirm the diagnosis of syphilis.

1. FTA–ABS - The fluorescent treponemal antibody absorption test checks for the presence of antibodies that develop after infection with treponema pallidum.

2. MHA-TP - Microhemagglutination assay for treponema pallidum.

What Is the Treatment for Tabes Dorsalis?

Treating the infection and reducing the complications are primary aspects of treating this disorder. The nervous system disorder caused due to tertiary syphilis is irreversible, and no medicine can repair the damage.

• Medications - Antibiotics are useful against the bacterium. Penicillin is the drug of choice in treating syphilis. Tabes dorsalis is a complication of long-standing untreated syphilis. So, long-term treatment with penicillin is required to treat the disorder. Treatment with penicillin will cure the infection but cannot repair the nerve damage.

This disorder is painful, and medicines to manage the pain are essential. Non-steroidal anti-inflammatory drugs and opioid analgesics are the drug of choice for managing the pain caused due to the disease.

• Supportive Therapy - Physical therapy is essential for individuals with muscle weakness and loss of muscle tone. Exercise will help regain muscle strength and restore the function of the affected limbs, thereby improving the quality of life.

• Preventive Measures - Practice safe sex at all times. Use protection such as condoms before having sexual contact with anyone.

What Is the Prognosis of Tabes Dorsalis?

Tabes dorsalis is a highly debilitating disease. If left untreated, it can cause severe neurological complications. It can even cause paralysis of the limbs, memory loss, and vision loss. Although the infection can be treated with antibiotics, supportive care will control the further deterioration of health.

Conclusion:

Tabes dorsalis is a debilitating neurosyphilis condition that primarily affects the nervous system. It is characterized by progressive damage to the sensory nerves, leading to symptoms such as shooting pains, muscle weakness, loss of coordination, and sensory disturbances. If left untreated, Tabes dorsalis can result in severe disability and complications. However, with early diagnosis and appropriate medical intervention, such as antibiotics to treat the underlying syphilis infection and symptom management, the progression of the disease can be slowed or halted. It is crucial for individuals at risk of syphilis to undergo regular screenings and seek prompt medical attention to prevent the development of Tabes dorsalis and its long-term consequences.