Symptoms of Tarsal Tunnel Syndrome
Tarsal tunnel syndrome symptoms include paresthesias (pins and needles) as well as pain radiating around the ankle and to the underside of the toes. Numbness and burning sensations can also be noted in this distribution. Standing will increase the symptoms and elevating the foot will reduce the symptoms.
Increasing nerve involvement can produce hot or cold sensations and electrical discharge symptoms (Tinel’s sign). Prolonged standing in any individual can increase the swelling of the foot in general and this swelling can worsen the symptoms of tibial nerve entrapment.
The tibial nerve moves in the tarsal tunnel with ankle motion. Plantar flexion (pushing the foot and toes to the floor) loosens the nerve and dorsiflexion (pulling the toes and foot to the nose) will stretch the nerve. Stretching the nerve will increase symptoms.
Diagnosis of Tarsal Tunnel Syndrome
History, examination and special testing confirm the diagnosis of this condition. The history is exactly like that noted above.
Testing essentially consists of one or two tests. The Tinel’s test has to do with the exquisite sensitivity of any nerve at an injury point. A nerve that is injured will fire an ectopic focus (a lightening bolt of electricity) down to the end of nerve when stimulated. Percussion of the injury area will elicit this “lightening bolt”. In the case of tarsal tunnel syndrome, the injury point is where the nerve wraps around the ankle. A positive test will cause an electrical “zap” into the foot with percussion of the nerve at the ankle.
Some physicians will perform a two-point discrimination test. This test uses the ends of monofilament fishing line on a tool that can separate these two points at a specific distance. This tool is used to determine the smallest distance that a patient can identify the distance between these two points. In tarsal tunnel syndrome, this distance will be larger than normal in bottom of the foot as the sensitivity of the skin here diminishes.
Finally, an electrical test called an EMG/NCV can be used to determine if there is conduction loss or muscle weakness. A negative test (no findings) would not preclude a diagnosis of tarsal tunnel syndrome.
Treatment of Tarsal Tunnel Syndrome
Treatment for tarsal tunnel syndrome depends upon the severity of the symptoms. Intermittent symptoms that do not bother the patient and do not wake them up at night generally do not need to be treated.
With increasing symptoms, medications such as NSAIDs (Motrin, Aleve) can be helpful. Injection of steroid into the tarsal tunnel can be effective to reduce symptoms.
If symptoms continue without relief or motor weakness occurs, surgical decompression of the nerve can provide long-term relief.
For additional resources on tarsal tunnel syndrome, or to determine treatment options for your case of tibial nerve entrapment, please contact Dr. Donald Corenman, back doctor and spine specialist serving the communities of Vail, Aspen, Denver and Grand Junction, Colorado.