Just like the carpal tunnel in the wrist, there is a band of fibrous tissues around the ankles, which form the tarsal tunnel at the joint of the legs and the feet. Through the tarsal tunnel runs the tibial nerve which causes sensations in the feet and the toes. The toes and fingers tingling is nothing but the reaction that occurs when the tarsal tunnel becomes squeezed or compressed, which further leads to a depression in the posterior tibial nerve. Tarsal Tunnel syndrome is similar to the carpal tunnel syndrome that affects the hands and the fingers. The tarsal tunnel syndrome could be caused by performing activities that may put pressure on the posterior tibial nerve. A person who has been diagnosed with flat feet is especially at the risk of developing this syndrome. The fallen arches of the feet can cause the compression of the tibial nerve. Any enlarged or abnormal structure within the tunnel can also put some pressure on the nerves. Some of the examples of such structures are ganglion cysts, swollen tendons, varicose veins, and bone spurs caused by arthritis. Ankle sprains may also produce inflammation and swelling around the tunnel. This can cause compression of the nerves.
The common symptoms of tarsal tunnel syndrome and carpal tunnel syndrome include tingling in the toes and fingers respectively. There may be temporary numbness and shooting pains in the toes. These symptoms are typically felt in the ankle, towards the interior of the joint. The symptoms could also be experienced at the bottom of the foot. Overuse of the foot could bring on such symptoms. Prolonged standing, exercising, and walking are some of the common causes of aggravated injuries to the tarsal tunnel.
Tarsal tunnel may cause permanent nerve damage, if not addressed immediately. However, before treatment is begun, proper diagnosis of the foot is very important. Appropriate treatment can only be initiated once the diagnosis has been finalized.
To diagnose the problem of the tingling in fingers and toes, the doctor will position your foot in a manner that the nerve of the foot can be tapped upon. The doctor taps on the nerve and waits to see if the symptoms are reproduced. The doctor also examines the area to see if there is presence of any abnormal mass. Sometimes, advanced imaging techniques are used to take pictures of the foot and check for tumors or cysts in the tarsal tunnel. If the initial treatment does not reduce the symptoms, further testing and ultimately surgery may be required.