Neuropathic Pain Syndromes

Tarsal Tunnel Syndrome

(Posterior Tibial Nerve Neuralgia)

Tarsal tunnel syndrome is pain along the course of the posterior tibial nerve, usually resulting from nerve compression.

Risk factors include abnormal foot function, inflammatory arthritis (eg, RA), fracture, ankle venous stasis edema, and hypothyroidism.

Pain (occasionally burning and tingling) is usually retromalleolar; it sometimes occurs in the plantar medial heel and may extend along the plantar surface as far as the toes. Pain is worse when patients stand and walk.

Diagnosis is by history and physical examination. Tapping or palpating the posterior tibial nerve below the medial malleolus often elicits distal tingling (Tinel's sign). Electrodiagnostic tests are often falsely negative. The cause of any swelling near the nerve should be determined.

Strapping the foot in a neutral or slightly inverted position or wearing an orthosis that keeps the foot inverted reduces nerve tension. If tarsal tunnel syndrome is caused by inflammatory arthritis, local injection of a corticosteroid/anesthetic mixture may be effective. Surgical decompression is occasionally necessary.

Dorsal Cutaneous Nerve Trauma

Dorsal cutaneous nerve trauma is injury to the sensory nerves on the dorsum of the foot, which often causes pain.

Pain in the dorsolateral aspect of the foot is usually caused by damage to an intermediate dorsal cutaneous nerve. Such damage often results from compression by ill-fitting shoes and is common after a plantar inversion ankle sprain. Arthritic changes and spur formation may irritate these nerves. Pain in the dorsomedial aspect may result from injury to the medial dorsal cutaneous nerve due to incorrect surgical technique during bunion surgery or from entrapment due to fibrosis.

Treatment consists of local injection of corticosteroids and strapping the foot in a neutral position or wearing custom-made shoes. Strapping the foot immobilizes the painful area. The strapping should be reapplied every 3 to 5 days. If entrapment due to severe fibrosis is suspected, surgery should be considered.

This topic was last updated May 2006.