Updated: Aug 13, 2018
A neuroma (sometimes referred to as a Morton’s Neuroma) is an entrapped nerve in the forefoot that may result from compression of the nerve between the two adjacent metatarsal bones and the associated deep intermetatarsal ligament or from abnormal foot biomechanics associated with certain foot types (2). Wearing certain shoes (e.g. narrow toe box, high heels) and participating in higher impact activities can also cause irritation and pain to the nerve.
Diagnosing a neuroma is often done clinically, based on one’s symptoms and a careful, thorough examination of the foot. Often, the person will describe having a numbness or tingling sensation and/or a shooting pain in the forefoot, usually between the 3rd & 4th toes (but the pain can be between other toes). The pain is worse while on the feet, but sometimes the neurological symptoms can also occur at random, even while sitting or lying in bed.
Radiographs will not show the neuroma but can give insight into one’s foot type that may predispose the person to developing the neuroma. An ultrasound or MRI is better at visualizing a neuroma, and I personally use MRIs to confirm its presence prior to surgical intervention. Other things in the same region of the foot that may cause similar symptoms include bursitis or another space-occupying lesion, metatarsalgia, or capsulitis (1). This is why a thorough examination is critical. You want to make sure you're treating the right thing!
There are several small adjustments that can be made to help improve neuroma symptoms. Wearing wider toe box shoes to allow for more room in the forefoot, avoiding higher heeled shoes to take pressure off the ball of the foot, and trying metatarsal pads or orthotics, may all provide relief. When these don’t work, injections are also a popular treatment option. For neuromas, this often involves injecting steroid or an alcohol solution around the area of the nerve. These injections differ from one another greatly, though, so it’s important to know what’s involved with each type, from frequency of injection, recovery time, and potential side effects.
Steroid injections are used to decrease inflammation, which, subsequently, helps with the pain. They should be spaced out about 3 months from one another and only be performed 3-4 times per year. The reason for this is that steroid has the potential of causing tissue atrophy, meaning that any tissue it touches (e.g. subcutaneous tissue, ligaments, skin, etc), it can cause it to thin and weaken. This can, in turn, lead to other problems, such as hammertoe deformities of the adjacent toes, plantar fad pad atrophy, and discoloration of the skin at the injection site. People with diabetes should also be aware that steroids can temporarily increase their blood sugar levels, so they should monitor them closely after each injection. Physicians may also recommend avoiding higher impact activities for a period of time after each injection, so it is important to take that into consideration when timing the injections.
Alcohol Sclerosing Injections
Alcohol sclerosing injections cause nerve degeneration and, after repeated injections, possible nerve destruction (1). These injections are typically done every 1-2 weeks and are done in a series of 3-7 injections. Unlike the steroid injections, where improvement of symptoms should be noticed within a day or two, alcohol sclerosing injections sometimes take 3 or 4 injections before some improvement is noticed. The side effects of these injections include continued pain and loss of sensation around the area of the injection site, as well as to the adjacent toes. The benefit of these injections, though, is that there will likely not be a rest period required after each injection, which means that activities can be resumed as normal the following day.
There are many conservative treatment options available for the treatment of neuromas with injections being among the most popular. There are potential risks and side effects associated with each injection type, though, so it is important to be informed and discuss the options with your physician before starting any treatment, and should conservative measures fail, surgical intervention can be considered.
DISCLAIMER: The above information is meant for educational purposes only and should not be construed as medical advice. Please contact the doctor, or your own healthcare professional, should you have questions or concerns related to your health.
1. Dockery, G. L. (1999). The treatment of intermetatarsal neuromas with 4% alcohol sclerosing injections. The Journal of foot and ankle surgery, 38(6), 403-408.
2. Gurdezi, S., White, T., & Ramesh, P. (2013). Alcohol injection for Morton’s neuroma: a five-year follow-up. Foot & ankle international, 34(8), 1064-1067.