An Overview of Neuroma

A neuroma is an often painful but typically benign abnormal growth of nerve tissue. It's sometimes referred to as a nerve tumor or "pinched nerve." A common type called Morton's neuroma grows between the third and fourth toes. Another common site is the back of the hand. However, neuromas can occur anywhere in the body.

Neuromas involve thickening of the nerve tissues, which often causes severe nerve pain. A neuroma can also change the way your brain interprets touch and lead to abnormal pain types categorized as dysesthesias.

Dysesthesia means abnormal sensation. These can be painful or just unpleasant (although that distinction can be hard to make.) Neuromas are associated with two types of dysesthesias that do cause pain, often in large amounts. They are:

• Allodynia: This is pain from stimuli that shouldn't cause pain, such as a light brush of fabric against the skin, moderate heat or cold, or a small amount of pressure from a waistband that's not too tight.
• Hyperalgesia: Heightened feeling of pain from stimuli that is normally painful; for example, bumping a body part against a door jamb might normally be a three or four on the pain scale, but a six or seven for someone with hyperalgesia.

Specific symptoms depend on the region of the body where the neuroma forms. In Morton's neuroma, which is most often between the third and fourth toes, symptoms include:

• Burning pain in the ball of the foot that may radiate into the toes
• Sharp, tingling pain that intensifies with activity
• Pain that's exacerbated by wearing shoes, especially if they're tight and/or narrow
• Numbness or unpleasant sensations
• Clicking sensation when you walk
• Pain after taking off shoes

Sometimes, a neuroma will cause pain in a larger area, which is called complex regional pain syndrome (CRPS). This usually develops over time. CRPS can lead to additional symptoms in nearby tissues and structures, such as:

• Changes in circulation and sweat production
• Changes in hair density
• Decreased bone density

Typically, these symptoms will improve when the neuroma is successfully treated.

The neuroma is basically a ball of scar tissue and long threads called axons, which form as the nerve attempts to heal. Not all neuromas are painful, but people don't usually notice the ones that don't hurt.

Neuromas are caused by injuries to a a nerve, which can be a laceration (cut), a crushing injury, nerve compression, or an excessive stretch. Common causes include:

• Surgery, especially limb amputations, mastectomy, and hernia repair
• Tight shoes
• High heels with pointed toes
• Flat feet or other genetic abnormalities
• Bunions
• Repetitive stress
• Pregnancy
• Illnesses such as rheumatoid arthritis or gout

While neuromas are often associated with amputations, they don't cause phantom limb pain. However, they can make it difficult or impossible to wear a prosthetic.

To diagnose a neuroma, your doctor will ask you about your symptoms and perform a physical exam. Often, they'll do what's called Tinel's test, which involves tapping over the path of the nerve to see if it causes pain or tingling.

Depending on the location of the suspected neuroma, they may also feel for a distinctive lump in the painful area.

You may also be sent for imaging. An x-ray can help rule out other potential causes of pain, and ultrasounds are good at spotting neuromas. Magnetic resonance imaging is sometimes used, but it can lead to false positives and is much more expensive than an ultrasound.

Doctors sometimes use a nerve block as well, which means they inject an anesthetic at the site of pain or along the known pathways of nerves believed to be involved. If it alleviates the pain, that confirms the diagnosis.

The initial treatment for a neuroma is nonsurgical and may involve medications and/or physical therapy. Some medications for neuroma include:

• Tricyclic antidepressants, such as Elavil (amitriptyline): These drugs change how the central nervous system processes pain signals. For neuromas, they can provide some relief from burning and tingling.
• Anticonvulsants, such as Neurontin (gabapentin), Tegretol (carbamazepine): These drugs are shown to relieve nerve pain in some people but evidence for their use with neuromas is limited. They're considered an alternative for people who can't tolerate tricyclic antidepressants or an additional treatment for those who need more relief than tricyclics offer.
• Serotonin Norepinephrine Reuptake Inhibitors, such as Cymbalta (duloxetine): SNRIs are commonly used to treat nerve pain and, like tricyclics, alter the way your brain processes pain signals.
• Corticosteroid injections, such as Medrol (methylprednisolone), Deltasone (prednisone): These medications are powerful anti-inflammatories. They can help relieve nerve compression from inflamed tissues.

Several physical therapy techniques can be used for neuromas, including:

• Desensitization exercises: This involves rubbing the residual limb with different textures to gradually decrease hypersensitivity.
• Electrical stimulation: This involves weak electrical current delivered to your muscles via electrodes. It can help alleviate muscle spasms, inflammation, and pain.
• Ultrasound: This provides deep heating to your soft tissues, which is thought to help them heal. This is a different procedure from ultrasound imaging, which is a diagnostic tool.

You can also try some lifestyle changes, such as:

• Resting and icing the area after activity
• For Morton's neuroma, wearing shoes with plenty of room in the toes and getting shoe inserts that relieve pressure on the neuroma

If other treatments fail, your doctor may recommend surgery. Two types are common:

• Decompression, which is done by cutting nearby structures that put pressure on the nerve
• Nerve removal, which can result in permanent numbness in the affected area

A common problem with nerve removal is that a new neuroma may form where the incision was made.

All surgery comes with risks, so it's usually considered best to try conservative treatments first. If you are considering surgery, make sure to discuss all potential risks with your medical-care team.

The pain from neuromas can be debilitating and, like all chronic pain, can wear you down mentally and emotionally. The good news is that you have a lot of treatment options to consider. Work with your doctor to figure out the right treatments for you.