Ewa Rolston

The Globe's Premier Foot Site

What Causes Mortons Neuroma

Overview

MortonMorton?s neuroma occurs as the nerve passes under the ligament connecting the toe bones (metatarsals) in the forefoot. Morton?s neuroma most frequently develops between the third and fourth toes, usually in response to irritation, trauma or excessive pressure. The incidence of Morton?s neuroma is 8 to 10 times greater in women than in men.

Causes

In many cases, a neuroma may develop as a result of excessive loading on the front of the foot. Sometimes, a patient?s anatomic alignment in the forefoot contributes to the overload. There may be some cases where the neuroma develops spontaneously, for no obvious reason. However, once the nerve is irritated, pressure from walking, and from the adjacent bony prominences (metatarsal heads), as well as from the intermetatarsal ligament that binds the heads together, all may contribute to persistent pain. Repetitive pressure on the nerve causes localized injury with resulting scarring and fibrosis of the nerve. This leads to symptoms in the distribution of the nerve.

Symptoms

While the condition may at first only appear during heavy repetitive stress or when wearing particular shoes which aggravate the foot, the Neuroma can become increasingly inflamed and produce more constant discomfort, lasting days or weeks. Runners may experience pain pushing off from starting blocks. Tight or narrow shoes as well as high heels likewise aggravate the Neuroma. A checklist of symptoms includes burning pain, occasionally numbness in the ball of the foot. Radiating pain from the ball of the foot to the toes. Intensifying pain during activity and when wearing shoes. Occasional numbness, discomfort, tingling or ?electrical shock sensation? in the toes. Pain between the third and fourth toes, often occurring from the outer side of one toe to the inner side of the adjoining toe. Pain upon leaving the starting blocks in running sports.

Diagnosis

Based on the physical examination, your doctor usually can diagnose a Morton's neuroma without additional testing. A foot X-ray may be ordered to make sure that there isn't a stress fracture, but it will not show the actual neuroma. If the diagnosis is in doubt, your doctor may request magnetic resonance imaging (MRI) of the foot.

Non Surgical Treatment

To help relieve the pain associated with Morton's neuroma and allow the nerve to heal, consider the following self-care tips. Take anti-inflammatory medications. Over-the-counter nonsteroidal anti-inflammatory medications, such as ibuprofen (Advil, Motrin IB, others) and naproxen (Aleve), can reduce swelling and relieve pain. Try ice massage. Regular ice massage may help reduce pain. Freeze a water-filled paper cup or plastic foam cup and roll the ice over the painful site. Change your footwear. Avoid high heels or tight shoes. Choose shoes with a broad toe box and extra depth. Take a break. For a few weeks, reduce activities such as jogging, aerobic exercise or dancing that subject your feet to high impact.Morton

Surgical Treatment

For severe or persistent pain, you may need surgery to remove the neuroma. Once the nerve is gone, you permanently lose feeling in the affected area. One alternative to surgery is to undergo neurolysis injections. These use chemical agents to block pain signals. Another alternative is to take a prescription pain reliever that alleviates nerve pain.