Any action that shifts the body weight onto the front of the foot, such as wearing high heels, climbing stairs and running, can make a neuroma worse. Some doctors will describe a neuroma as a nerve tumor. However, don't worry because neuromas are not cancer and will not spread to other parts of your body. It is an injury to a nerve, that occurs slowly, over a long period of time.
Neuromas frequently start as a numbness or tenderness in the ball of the foot. This is the area just behind the base of the toes. As the swelling increases, pain and strange sensations such as numbness, burning and tingling in the area can radiate out into the toes or back into the foot. The area may be hot or very swollen and, just as mysteriously, the symptoms can disappear and reappear. At first, the pain is only present when weight bearing in tight shoes. As it gets worse, spontaneous shooting pains, often like electric shocks, can be felt even when you're off your feet.
Diagnosis of a Neuroma
Your doctor will make the diagnosis relying on your history and description of the problem and the physical examination. There is a simple test to find a neuroma. The doctor will squeeze the area between the bases of the toes to see if it is sensitive. If a neuroma is present, the doctor, and sometimes you, will feel a "click", as the soft neuroma mass squishes out between the long metatarsal bones. You may feel the pain shooting out into your toes or back into the foot. This is called a Mulder's Sign, and is the diagnostic sign of the presence of Morton's Neuroma.
Finally, the doctor will do an x-ray to see if there are any other problems present. The nerve and neuroma are soft tissue and don't show on a standard x-ray. However, the doctor can tell if the metatarsals are close together and if the toes are spread apart-both signs of a neuroma. If the diagnosis is at all unclear, a soft tissue imaging technique called an MRI may be done to actually see the neuroma mass.
Causes of Neuromas
To understand why neuromas develop, it is important to know how the nerves connect to the toes. The nerve that carries sensation signals back from the toes starts in the midfoot between the metatarsals. The nerve passes beneath a strong ligament, or soft-tissue band, that holds the metatarsal heads together. Just after it passes this band, it splits in half forming a Y. Each half then connects to the adjacent sides of the two toes.
The neuroma usually develops just under or beyond the tight ligament. Why? Well, imagine that the nerve is the bow of a violin and the tight ligament is the string. The constant pulling of nerve over the ligament irritates the nerve and causes the nerve to thicken and scar. The nerve also can get pinched between the two metatarsal bones that it passes between. A scarred nerve doesn't carry signals well and may send back strange signals to the brain such as burning, pain and tingling. So, instead of beautiful music, we get terrible noise.
Anything that stretches and pulls the nerve will aggravate the condition. For instance, wearing high heels aggravates neuromas in three ways. First, the higher heel will push the toes up from the rest of the foot and cause the nerve to tighten and pull harder against the tight ligament. Second, the tight toe box squeezes the front of the foot together leaving less space between the metatarsal bones for the nerve to rest. Finally, the body weight is put more on the ball of the foot increasing the pressure on the nerve. All 3 are bad news for you and your neuroma.
Treatment for Neuromas
The most significant help that you can give yourself to lessen the pain and allow the injured nerve to heal is to avoid tight, short or pointed shoes. If the metatarsal bones are allowed to splay or spread out naturally, as when you're barefoot, many neuromas will get better on their own. An oral anti-inflammatory medicine like ibuprofen, naproxen sodium or aspirin can help. The application of moist heat can help.
If the home remedies do not relieve your pain or if you have suffered several episodes, see your doctor for care. After the diagnosis is made, the doctor may apply special padding to the foot to take the pressure off the area. An injection of an anti-inflammatory medicine (cortisone) mixed with numbing medicine (xylocaine) may be put into the area surrounding the nerve to calm it down. The doctor may also prescribe a prescription anti-inflammatory medication or begin physical therapy treatments, to help the injured nerve to heal.
If these treatments are not effective at calming the neuroma down, the podiatrist may dispense orthotics to help control the abnormal mechanical structure of your foot. By preventing the arch from dropping, the the nerve will not be stretched as much.
Treating a Neuroma with Surgery
Finally, if these more conservative treatments don't work, then the faulty nerve may need to be removed or destroyed. This is not as bad as it sounds. This is only a sensory nerve that doesn't control any muscles and only provides sensation to a small area between the toes. The nerve is removed through an incision in the top or bottom of the affected area. The nerve is identified and snipped just behind the swollen part and just beyond where it splits in two. Frequently, the tight ligament between the metatarsal bones is also cut to allow more room. It is a relatively minor procedure with possible complications that include infection, swelling and pain. Rarely, a portion of the remaining nerve may become tender and require additional surgery.
Another procedure involves the destruction of the sensitive nerve through the injection of caustic medications. Either way, the area between the affected toes is likely to remain numb forever. However, this is rarely more than a minor annoyance.
When the nerve is removed, the pain rarely recurs in that spot. However, it is possible to develop another neuroma between two other toes or in the other foot. This is because the underlying conditions that caused the first one to develop are still present. So, you must be careful about what kinds of shoes you are wearing and the amount of pressure you put on the ball of the foot. If your podiatrist dispensed orthotics, then be sure you are wearing them and get them replaced regularly. Finally, if a new neuroma is developing, seek attention sooner rather than later. Early treatment may help you avoid future surgery.