An Overview of Neuropathic Pain

Neuropathic pain, or nerve pain, is one of the most intense types of chronic pain, often described as sharp, stinging, or burning. It is pain caused by damaged nerves or a problem with the nervous system. While neuropathic pain can be debilitating, the upside is that there are medications to treat it, and they work by changing the way the brain interprets pain.

Many terms are used to describe neuropathic pain, such as:

• Sharp
• Shooting or "electrical shock"
• Burning or "hot"
• Tingling, "pins and needles," or "prickling"
• Stabbing

Neuropathic pain can occur all the time or come in spurts. Likewise, neuropathic pain can range in intensity from being mild and nagging to severe and disabling.

Interesting, neuropathic pain tends to be worse at night, which may disrupt your sleep. It also tends to flare at rest, which may affect relaxation or mealtime. Overall, the negative impact neuropathic pain has on one's quality of life can lead to psychological problems, such as depression and anxiety.

You can develop neuropathic pain for many reasons. For instance, some types of neuropathic pain are caused by medications, like certain chemotherapy drugs. Others may result from a disease that affects the nervous system, such as:

• Guillain-Barré syndrome
• HIV
• Alcoholism
• Multiple sclerosis
• Multiple myeloma
• Cancer

Neuropathic pain is also common in diseases that attack sensory nerves, such as diabetes, and in conditions where certain nerves are inflamed or compressed, as in carpal tunnel syndrome or sciatica. Nerve pain may also result from trauma, like with spinal cord injury, where nerves are damaged or severed.

Phantom limb pain is another neuropathic pain disorder in which pain feels as if it is coming from a limb that was amputated.

Unfortunately, some types of neuropathic pain have an unknown origin or a cause that is not completely understood. Reflex sympathetic dystrophy (CRPS) is an example. Though the cause may not be fully known, the pain is very real.

The diagnosis of neuropathic pain requires a detailed medical history and physical examination, which are often enough to determine the "why" behind a person's neuropathy. However, sometimes the diagnosis requires an evaluation by a specialist, like a neurologist.

In this instance, the diagnosis may require more testing including blood tests, nerve tests like electromyography (EMG), or imaging tests, like magnetic resonance imaging (MRI) of the brain or spinal cord.

Treatment of neuropathic pain first entails addressing the underlying problem. For example, if a person has neuropathic pain from diabetes, optimizing blood sugar (glucose) control is an essential next step. Bear in mind, though, enhanced glucose control cannot generally reverse the neuropathy, although it can prevent it from getting worse and ease current symptoms.

As another example, if a medication is causing debilitating nerve pain, removal or a decrease in the dose of the offending drug may be all that is needed.

Besides treating the underlying problem, medication is often needed to manage neuropathic pain.

For the vast majority of patients, treatment of neuropathic pain involves taking one of the following:

• An antidepressant like Cymbalta (duloxetine) or Elavil (amitriptyline)
• An anti-seizure medication like Neurontin (gabapentin) or Lyrica (pregabalin)

All of the drugs may cause unpleasant side effects.

The most common side effects of Cymbalta include:

• Nausea
• Dry mouth
• Tiredness
• Constipation
• Decreased appetite
• Excess sweating

Elavil carries a risk for potentially fatal heart toxicity, as well as other bothersome side effects, including:

• Dry mouth
• Constipation
• Urinary retention
• Lightheadedness or dizziness when standing up

Neurontin may cause:

• Coordination problems
• Tiredness
• Difficulty speaking
• Nausea and vomiting
• Swelling in the lower legs

Lyrica side effects include:

• Dizziness
• Tiredness
• Dry mouth
• Swelling
• Blurry vision
• Weight gain
• Difficulty concentrating

In addition, you have to wean gradually off of these medications if you want to stop taking them. Withdrawal can be unpleasant and potentially dangerous in some cases.

Opioids like Vicodin (hydrocodone/acetaminophen) and Percocet (oxycodone/acetaminophen) are not as effective for treating neuropathic pain and, thus, are considered second-line treatments.

In addition to their questionable benefit, opioids are associated with several side effects that may severely affect your quality of life. They include:

• Drowsiness
• Dizziness
• Constipation
• Dry mouth
• Nausea and vomiting
• Itching
• Increased sweating
• Shallow breathing
• Slow heart rate
• Loss of consciousness
• Involuntary muscle twitches (myoclonic jerks)
• Urinary retention
• Memory and thinking problems

In addition to these side effects, there is a nationwide concern about opioid addiction and abuse, which must be considered.

There are some types of neuropathic pain that may require a unique treatment plan.

For instance, if your neuropathic pain is localized (confined to a small area), as is often the case in postherpetic neuralgia, a topical (on the skin) therapy, like a lidocaine patch may be used.

In other instances, surgery may be necessary—for example, to release a compressed nerve, as in carpal tunnel syndrome. In the case of a herniated disc, in which an inflamed spinal nerve is a culprit behind the pain, an epidural steroid injection into the spine is sometimes performed.

Lastly, sometimes certain medications are used to treat specific neuropathic pain conditions. A classic example is trigeminal neuralgia, which is characterized by severe, stabbing neck and facial pain. This disorder is treated with the anti-seizure medications Tegretol (carbamazepine) or Trileptal (oxcarbazepine).

A variety of complementary therapies can help relieve neuropathic pain. These therapies are commonly used in combination with medications and include:

• Physical or occupational therapy
• Electrical stimulation
• Relaxation therapy
• Acupuncture
• Massage therapy

Neuropathic pain is often chronic and can be challenging to treat. The good news is that there are a lot of treatment options, and often it's the combination of therapies that does the trick. With that, remain persistent in your efforts to soothe your pain—but also aware that it's often a trial and error process.