Neuromas and Complex Regional Pain Syndrome

Definitions

Neuroma

A neuroma is a disorganized growth of nerve cells at the site of a nerve injury. A neuroma occurs after a nerve is partially or completely disrupted by an injury — either due to a cut, a crush, or an excessive stretch. The neuroma is a ball-shaped mass at the site of the injury, which can be painful or cause a tingling sensation if tapped or if pressure is applied. Although not always the case, a neuroma can be extremely painful and can cause significant loss of function for the patient by limiting motion and contact with the affected area.

Neuromas can occur after trauma and even after surgery in any region in the body since most areas have nerve fibers providing feeling. Painful neuromas are common after amputations in the hand and upper extremity (arm) and in the lower extremity (leg). They are also seen following hernia repair in the groin.

Complex Regional Pain Syndrome (previously known as Reflex Sympathetic Dystrophy)

In some cases, the pain associated with neuromas can cause a more generalized pain in the region of the injury. While the injury may have been localized just to the nerve, over time the pain can migrate to the non-injured adjacent skin, which becomes painful to the touch. Other changes in the affected area can include changes in circulation, hair growth and/or hair loss, changes in sweat production, and even decreased bone density. If these changes are associated with a neuroma, often the treatment of the neuroma can help to decrease pain as well as these other signs and symptoms.

Learn more about Complex Regional Pain Syndrome (PDF)

Diagnosis and Treatment

Neuromas can be diagnosed by history and physical exam of patients. The areas of sensitivity are identified by tapping directly on known pathways for peripheral nerves, which should elicit the painful symptoms and often a tingling sensation. These areas are then injected with a local anesthetic either at those sites or in the nerves which are affected (known as a nerve block). If relief is achieved, it is more likely that surgical treatment of that neuroma will help alleviate pain. The neuroma is then excised, and the nerve is placed in an area in the deeper tissues where it will not receive frequent direct stimulation (from pressure or contact) during normal activities. Often, medications are used in conjunction with surgical treatment to modulate the body’s response to the neuroma pain. This often enhances the effects of surgery. Antidepressant medications and anti-seizure medicines are often prescribed for treatment prior to surgical correction as well. This is done in collaboration with a specialist in the treatment of chronic pain.

Common Sites of Neuromas

Amputation sites in the hand, upper extremity and lower extremity are common sites for neuromas. Painful areas in amputations stumps are often associated with a severed nerve ending close to the skin. These stumps often receive frequent stimulation during daily activities and can create significant pain. Often by removing the neuroma from the stump end and burying the nerve in deeper tissues, the pain can be relieved or lessened. Other areas of sharp or blunt trauma in the hand and other regions of the body, including areas that have undergone surgery, can become chronically painful in a similar way to amputation sites if a nerve is injured and forms a neuroma.

Groin pain after significant blunt or sharp trauma or after inguinal hernia surgery is often caused by injured nerves with neuroma formation in those areas. Again, a nerve block can be effective in terms of identifying affected nerves and planning treatment. By removing the injured nerve segments and burying the nerves in deeper tissues, significant relief can often be achieved.