Neuropathic Pain is a complex, chronic pain state that usually is accompanied by tissue injury. With neuropathic pain, the nerve fibers themselves become “painful” and may be damaged, dysfunctional, or injured. These damaged nerve fibers send incorrect signals to other pain centres. The impact of nerve fiber injury includes a change in nerve function both at the site of injury and areas around the injury.
Despite this not all pain can be classified as “neuropathic” in nature and this is a very important point to remember. Dr. Dominic Hegarty (Clinical Director to Pain Relief Ireland) points out that it is possible to “screen” for neuropathic pain by taking a thorough clinical history and monitoring for certain features. While there are no specific tests to help make the diagnosis there are recognisable features.
“Identifying the presence or not of neuropathic nerve pain can completely change the way treatment is provided and the type of treatment needed in every case. Combination therapy maybe the only way to ensure the nerve pain settles to an acceptable level”.
Prevalence and Incidence
According to the International Association of the Study of Pain (IASP) general population studies, using validated screening instruments, have found that 7–8% of adults currently have chronic pain with neuropathic characteristics. The incidence (new cases) of neuropathic pain was found in a Dutch study to be around 8 cases per 1,000 person-years.
- A study in Germany found that 37% of people attending primary care clinics with chronic low back pain have predominantly neuropathic pain. This figure was equivalent to 14% of female and 11% of male Germans.
- In the United Kingdom, 26% of people with diabetes were found to have peripheral neuropathic pain. Worldwide, this figure translates to some 47 million individuals, which will increase as the prevalence of diabetes grows (from 2.8% in 2000 to an estimated 4.4% in 2030).
- Of the 33 million people infected with HIV across the world, around 35% have neuropathic pain, which does not respond well to standard treatments.
- A Norwegian study found that 40% of people have persistent pain after surgery, of which a quarter of cases have neuropathic characteristics. Neuropathic postsurgical pain is more likely to be severe and persistent than non-neuropathic postsurgical pain.
- Approximately 20% (18.7–21.4%) of people with cancer have cancer-related neuropathic pain, as a result of either the disease or its treatment.
- The lifetime incidence of herpes zoster (shingles) is around 25%. Studies in the United States and the Netherlands found that 2.6% and 10%, respectively, will develop chronic postherpetic neuralgia.
The issues around neuropathic pain are so important that the IASP made 2014-2015 the Global Year for Neuropathic pain in order to increase awareness.
Diagnosing Neuropathic Pain
To diagnose neuropathic pain, an interview and a physical examination is usually required. Specifically your doctor will ask questions about how you would describe your pain, when the pain occurs, or whether anything specific triggers the pain. There are several common features one can expect and there are several “screening tools” to help. At Pain Relief Ireland we commonly use the DN4, PainDetect or Leeds Neuropathic pain screening questionnaires to help make this diagnosis.
Occasionally nerve conduction studies and MRI data may be required to exclude other medical causes or to define the condition more thoroughly. Biochemistry and blood markers may also be helpful.
It is always important to exclude other cause of your nerve pain.
Neuropathic Pain Treatment
There are several different treatment options and they usually depend on the need of the individual and the pain intensity.
Very often agents to reduce the pain activity of the nerve fibers (i.e amitriphyline / pregablain / gabapentin) are considered. Combining this with other analgesic agents to help reduce the pain intensity would be very common. “Sometimes taking oral analgesics alone will not make any impact and pain interventions ( pain injections) and advanced deneravfion techniques are the best option” according to Dr. Hegarty.
Other kinds of treatments can also help with neuropathic pain. Some of these include:
- Physical Therapy
- Acupuncture & Massage
- Psychological support in the form of Active Cognitive therapy (ACT)
- Relaxation & pacing techniques
Unfortunately, neuropathic pain often responds poorly to standard pain treatments and occasionally may get worse instead of better over time. For some people, it can lead to serious disability. A multidisciplinary approach that combines therapies, however, can be a very effective way to provide relief from neuropathic pain.