Abadie's sign of tabes dorsalis

Abadie's Sign of Tabes Dorsalis

Abadie's sign is a clinical finding associated with tabes dorsalis, a form of neurosyphilis. This sign is characterized by the absence or marked decrease of pain sensation when pressure is applied to the Achilles tendon. It is named after the French neurologist, Jean Marie Charles Abadie, who first described this phenomenon.

Etiology and Pathophysiology

Tabes dorsalis is caused by the degeneration of the dorsal columns and dorsal roots of the spinal cord, which occurs as a late manifestation of untreated syphilis. This degeneration leads to a variety of sensory disturbances, including the loss of proprioception, vibratory sensation, and reflexes. The specific mechanism by which Abadie's sign occurs is not fully understood, but it is thought to be related to the loss of sensory nerve fibers in the Achilles tendon.

Clinical Presentation

Patients with Abadie's sign typically present with a history of syphilis and symptoms of neurosyphilis, such as ataxia, paresthesia, and impaired proprioception. The sign is elicited by squeezing the Achilles tendon, a maneuver that normally causes discomfort or pain. In patients with Abadie's sign, this action provokes little to no pain, despite the fact that the tendon may be inflamed or damaged.

Diagnosis

The diagnosis of Abadie's sign is primarily clinical, based on the patient's history and physical examination findings. However, the diagnosis of the underlying tabes dorsalis requires further investigation, including serological tests for syphilis (VDRL, FTA-ABS) and examination of the cerebrospinal fluid (CSF) for signs of neurosyphilis.

Treatment

Treatment of Abadie's sign involves addressing the underlying cause, tabes dorsalis. This typically includes antibiotic therapy, such as penicillin, to treat the syphilis infection. Pain management and physical therapy may also be necessary to address the symptoms associated with the condition.

Prognosis

The prognosis for patients with Abadie's sign depends on the stage of tabes dorsalis at the time of diagnosis and the effectiveness of treatment. Early diagnosis and treatment of syphilis can prevent the development of tabes dorsalis and associated signs. However, for patients who already have neurological damage, treatment may not reverse the condition but can help manage symptoms and prevent further progression.

See Also

• Neurosyphilis
• Syphilis
• Achilles tendon
• Proprioception