An impromptu poll of my Facebook friends suggests that massage therapists are seeing an increasing number of clients with a complicated group of conditions collectively called peripheral neuropathy (PN). This refers to damage in the peripheral nervous system, which can include both spinal and cranial nerves. Not surprisingly, pain—ranging from itching and tingling to severe burning sensations—is a leading feature of PN.

PN affects about 10 percent of the general population. Its prevalence rises significantly with age, so this is something that any massage therapist with mature clients needs to be ready to address.

Types of PN

One of the challenges of this condition is that it can be the result of dozens of different problems that are not mutually exclusive, so a person’s PN may be the result of multiple factors. Different specialists organize this information in slightly different ways, but following is one way to map out types and causes of PN.

Inherited PN. This is related to an inborn genetic anomaly. A condition called Charcot-Marie-Tooth disease is the most common cause of inherited PN.

Acquired PN. Several different life events may lead to long-term nerve damage, although approximately 25 percent of PN cases show no known cause.

• Systemic disease: alcoholism and poorly controlled diabetes are the two leading causes of PN. Autoimmune disease is another contributor; PN can be a consequence of almost any condition that involves low-grade, chronic inflammation. Guillain-Barre syndrome is an autoimmune disease with a sudden onset—it may be the only form of acute PN.

• Infection: many viruses, including herpes simplex and zoster, HIV, polio, and West Nile virus, can cause nerve damage. Other pathogens, including those that cause diphtheria, Hansen’s disease (leprosy), and Lyme disease, are also associated with PN.

• Trauma: crushing injuries, damaged discs, and fractures of bones in the extremities can lead to mechanical irritation of nearby nerves. Trigeminal neuralgia, usually the result of an artery strangulating part of the trigeminal nerve, fits in this category.

• Toxic exposure: Agent Orange, many insecticides, arsenic, lead, mercury, solvents, and other toxins can cause nerve damage.

• Medication: drugs that treat HIV can cause PN. This is also a frequent and serious complication of chemotherapy.

• Metabolic upset: pituitary and thyroid tumors and liver dysfunction can lead to nerve damage. Deficiencies and pathologically high levels of some nutrients are associated with PN.

Recognizing PN

Signs and symptoms of PN depend on what types of nerves have been affected. Damage can change function in autonomic nerves, motor nerves, sensory nerves, or any combination of the three. Symptoms typically start bilaterally in the toes and feet, and progress to affect the lower legs. The fingers and hands might be next, and the arms follow. For reasons that are not entirely clear, PN usually affects the longest nerves first and shorter nerves later.

Sensory nerve damage may be the most common presentation of PN. When the affected neurons are large-diameter fibers, the senses of vibration and proprioception may be interrupted. The consequences of this include muffled sensations and a numb feeling, as if a thick blanket is covering the affected areas. Proprioceptive damage may present as a loss of tendon reflexes. If smaller-diameter nerves are targeted, then the sensations of pain and temperature are predominant. Often, both large- and small-diameter neurons are affected, resulting in numbness, paresthesia, and burning pain.

When motor neurons are affected, symptoms might include painful cramps, fasciculations (small areas of involuntary twitching), muscle wasting, and progressive weakness.

When PN affects autonomic nerves, a wide variety of symptoms may develop: digestive problems, including difficulties with swallowing and gastric motility; changes in sweating that can include both hyper- and hypohidrosis; unstable blood pressure that can lead to dangerous bouts of orthostatic hypotension; and changes in breathing and heart rate.

Diagnosis and Treatment

Surprisingly, given how extreme PN symptoms can be, this condition can be difficult to diagnose accurately. Some specialists have created algorithms to help sort out the many factors in a PN diagnosis, but the process is still somewhat scattershot for many patients.1 It can involve many expensive, painful, and invasive tests that range from blood tests and spinal taps to nerve conduction velocity tests and nerve biopsies.

One example of PN that is not difficult to diagnose is when it occurs as a side effect of chemotherapy. In this situation, it is important to address the PN symptoms so that the patient doesn’t have to limit his or her cancer treatment.

The most effective treatment options for PN involve identifying and working with the underlying problems first, when possible. Then, the pain and other symptoms can be addressed in a variety of ways, including over-the-counter and prescription analgesics, and antiseizure medications. Topical applications of capsaicin or lidocaine injections are sometimes recommended. TENS (transcutaneous electrical nerve stimulation) units can interrupt the pain signals and are successful for some patients. In worst-case scenarios, surgery to destroy the affected nerve or nerves may be attempted. Finally, physical and occupational therapy can be employed to minimize muscle weakness and set the stage for the best possible recovery.

Happily, this condition often has a positive prognosis—if treatment is enacted quickly and effectively. If the damage to affected neurons does not kill the entire nerve cell, function can return to normal or near-normal levels; but as the delay between onset and treatment gets longer, complete recovery becomes less possible.

Massage and PN

The research about massage therapy and pain in general is extremely promising. Pain related to arthritis, cancer, surgery, and many other situations responds positively to welcomed touch. But, because PN can involve hypersensitivity and even allodynia (the perception that all incoming sensation is painful), massage may not always be well-tolerated.

No single approach to working with PN has been demonstrated to be the “best.” Each massage therapist must call on the most current research, along with his or her education and expertise, to meet our clients’ needs.

Research suggests that many people with chronic nerve pain seek out complementary and alternative medicine (CAM) modalities,2 but massage is not among their top choices. Perhaps touch does not seem particularly appealing for someone whose nerve endings feel raw and scraped, especially since inadequate pain control is a leading reason why people look for help among alternative health-care providers.

Although the PN patients who seek CAM therapies tend not to seek massage as a first recourse, some studies have found that some people experience significant pain relief with careful bodywork. One of these was a case report called “Case Report of a Patient with Chemotherapy-Induced Peripheral Neuropathy Treated with Manual Therapy (Massage)”3 that led to a pilot study funded by the Massage Therapy Foundation.4 This study will assess the impact of therapeutic massage on the signs, symptoms, quality of life, and local circulation for clients with chemotherapy-induced PN. Preliminary findings from this project were presented as a poster at the International Massage Therapy Research Conference in April 2013. See an interview with the author at www.youtube.com/watch?v=CCzfjGMcvrs&feature=youtu.be.

Notes

1. M. Bromberg, “An Approach to the Evaluation of Peripheral Neuropathies,” Seminars in Neurology 25, no. 2 (2005): 153–9.

2. B. Brucelli and K. Gorson, “The Use of Complementary and Alternative Medicine by Patients with Peripheral Neuropathy,” Journal of the Neurological Sciences 218, no. 1 (2004): 59–66.

3. J. E. Cunningham et al., “Case Report of a Patient with Chemotherapy-Induced Peripheral Neuropathy Treated with Manual Therapy (Massage),” Support Care Cancer 19, no. 9 (2011): 1,473–6.

4. J. E. Cunningham, “Use of Therapeutic Massage to Treat Chemotherapy-Induced Peripheral Neuropathy (CIPN)” (research grant proposal, Massage Therapy Foundation, 2012).