Overview
A neuroma is an often painful enlargement of one of your body?s nerves. Morton?s neuroma is the name used to describe nerve enlargement in your foot, particularly enlargement of one of the nerves traveling to your toes in your forefoot. Morton?s neuromas most commonly develop in one of your intermetatarsal nerves, one of many nerve branches within your foot that originated in your spine. Morton?s neuroma is more likely to affect women than men.
Causes
The exact cause of Morton’s neuroma is not known. However, it is thought to develop as a result of long-standing (chronic) stress and irritation of a plantar digital nerve. There are a number of things that are thought to contribute to this. Some thickening (fibrosis) and swelling may then develop around a part of the nerve. This can look like a neuroma and can lead to compression of the nerve. Sometimes, other problems can contribute to the compression of the nerve. These include the growth of a fatty lump (called a lipoma) and also the formation of a fluid-filled sac that can form around a joint (a bursa). Also, inflammation in the joints in the foot next to one of the digital nerves can sometimes cause irritation of the nerve and lead to the symptoms of Morton’s neuroma.
Symptoms
Outward signs of Morton’s neuroma, such as a lump, are extremely rare. Morton’s neuroma signs and symptoms, which usually occur unexpectedly and tend to worsen over time, include, pain on weight bearing (while walking) – a shooting pain affecting the contiguous halves of two toes, which may be felt after only a short time (of weight bearing). Sometimes there may be a dull pain rather than a sharp one. Most commonly, pain is felt between the third and fourth toes. Typically, a patient will suddenly experience pain while walking and will have to stop and remove their shoe. Burning. Numbness. Parasthesia, tingling, pricking, or numbness with no apparent long-term physical effect. Commonly known as pins-and-needles. A sensation that something is inside the ball of the foot.
Diagnosis
Morton?s neuroma can be identified during a physical exam, after pressing on the bottom of the foot. This maneuver usually reproduces the patient?s pain. MRI and ultrasound are imaging studiesthat can demonstrate the presence of the neuroma. An x-ray may also be ordered to make sure no other issues exist in the foot. A local anesthetic injection along the neuroma may temporarily abolish the pain, and help confirm the diagnosis.
Non Surgical Treatment
If symptoms are severe or persistent and self-help measures did not help, the doctor may recommend corticosteroid injections, a steroid medication that reduces inflammation and pain is injected into the area of the neuroma. Only a limited number of injections are advised, otherwise the risk of undesirable side effects increases, including hypertension (high blood pressure) and weight gain. Alcohol sclerosing injections, studies have shown that alcohol injections reduce the size of Morton’s neuromas as well as alleviating pain. This is a fairly new therapy and may not be available everywhere. The doctor injects alcohol in the area of the neuroma to help sclerose (harden) the nerve and relieve pain. Injections are typically administered every 7 to 10 days. For maximum relief 4 to 7 injections are usually needed.
Surgical Treatment
The above measures are often sufficient to resolve Morton?s Neuroma. Should the condition persist or worsen despite these efforts, surgery may be recommended to remove the Neuroma. The surgery requires only a short recovery period, though permanent numbness in the affected toes can result, so such surgery is generally used as a last resort.
Prevention
The best way to prevent a neuroma is by avoiding the things that cause them. Review your risk factors. If relatives have had similar problems, or if you know that you pronate or have any problem with the mechanics of your foot, talk with a podiatric physician about the correct types of shoes and/or orthoses for you. If you are not sure whether you have such a problem, the podiatric professional can analyze your foot, your stride and the wear pattern of your shoes, and give you an honest evaluation. Remember, though, that sometimes neuromas, like other conditions, can develop for no discernible reason. With this in mind, be good to your feet, and be aware of any changes or problems. Don?t wait to report them.