Foot neuroma refers to a mass growing around the plantar nerve in the foot as a result of long-term repetitive compression or irritation. The most common type of foot neuroma is called Morton's neuroma, also known as intermetatarsal neuroma, Morton's foot, Morton's toe, or Morton's disease. This condition must be distinguished from simple metatarsalgia, which features similar symptoms and is also located in the ball of the foot.
The medical name for Morton's neuroma is intermetatarsal neuroma, referring to the fact that it generally occurs between the third and fourth metatarsarsals, or toe bones. However, Morton's neuroma can also develop in other parts of the foot. In this foot condition, repeated irritation or compression of the plantar nerve in the foot leads to swelling or thickening of the nerve and, eventually, nerve damage. The mass that grows between the metatarsals is noncancerous but can cause pain, numbness, a tingling or burning sensation, or the feeling that a small pebble is lodged under the ball of the foot while one is walking or standing.
Morton's neuroma often happens in women who frequently wear high heels or shoes with narrow toe boxes, which put excessive pressure on the toes. The condition might also be caused by repeated high-impact activities, such as aerobics, tennis, or jogging. Those at higher risk for developing Morton's neuroma include individuals who are overweight, those who have a history of other foot problems, and those who have arthritis or gout.
Treatment for foot neuroma varies according to the severity of the individual's symptoms. Mild to moderate foot neuroma can be treated with some combination of ice massage at home, the wearing of orthotic devices, taking ibuprofen or other nonsteroidal anti-inflammatory medications, and making modifications in one's activities to alleviate symptoms. Other treatment possibilities to temporarily relieve painful symptoms include cryogenic neuroablation, in which nerve endings are frozen, and injection of cortisone or a local anesthetic into the painful area. Surgery is considered a treatment of last resort because it typically results in the permanent numbness of one or more toes.
Although foot neuroma is common, other types of neuroma can occur in various parts of the body. Morton's neuroma should not be confused with types of neuroma that are not related to the foot. These include acoustic neuroma, which is a tumor on the nerve leading from the inner ear to the brain, and amputation or "stump" neuroma, which happens when the severed nerves of an amputated limb begin to regrow abnormally.