What if you had successfully battled cancer but now you have a constant “socks and gloves” kind of feeling, where your sense of touch in your hands and feet is muted or distorted? Maybe your hands and feet are cold all the time. It’s hard to button a shirt or pick up a coin. Tingling and burning in your hands and feet keep you up at night. Sharp jolts of electrical pain occur without warning. You’re not sure about your balance, and a fall could be devastating. Nothing seems to help. Will this ever get better?
What is Peripheral Neuropathy?
Peripheral neuropathy (PN) is a stunningly vague label for the results of a wide variety of problems. It can develop as a freestanding disorder, but it is more often a complication or consequence of another issue. PN is notoriously difficult to treat, and it can outlast its initial causes by months or years.
About 20 million people in the United States have PN of one kind or another. When it affects only one nerve, it can be called mononeuropathy, but when it affects multiple nerves, it is called polyneuropathy.
PN is almost always a symptom, not a disease in itself. It is usually the result of nerve damage brought about by some other disease or challenge.
Metabolic disruptions can cause PN: Diabetic neuropathy arises from a combination of hyperglycemia and poor circulation to nerves in the extremities. Certain vitamin deficiencies can also alter peripheral nerve function as well, especially B12.
Nerve compression situations like carpal tunnel syndrome or thoracic outlet syndrome can cause PN from direct mechanical impairment; other injuries that damage nerves would fit under this description as well.
Some infections can cause PN, including herpes simplex, herpes zoster, HIV, Lyme disease, and Hansen’s disease.
Autoimmune diseases like lupus, Sjögren syndrome, and sarcoidosis sometimes have a PN component, and one autoimmune condition, Guillain-Barré syndrome, involves immune system attacks specifically on peripheral nerves.
Long-term exposure to some toxic substances can also damage the nerves, so PN is sometimes seen as a complication of alcoholism, exposure to heavy metals and solvents, and some medications—which leads us to the main topic for this discussion of PN: chemotherapy-induced peripheral neuropathy, or CIPN.
A Little Nervous System Review
To talk about CIPN and the role massage therapy might play in this context, it will be useful to do a short review of some structure and function of the nervous system.
Leaving out higher levels of consciousness (involving emotion, memory, learning, executive function, and all the fun stuff), the nervous system operates in three main functional domains: motor function, sensory function, and autonomic function.
Motor function describes how voluntary and reflexive messages that initiate in the central nervous system are passed along neuron fibers that carry those messages to muscles and glands. The muscles and glands then contract or secrete. They stop contracting and secreting when the impulses stop.
Sensory function describes how impulses are generated in the body and passed via both simple and complex pathways up the spinal cord and into the brain. There, they are sorted, recognized, and assigned meaning. Sometimes that meaning elicits a motor response that initiates in the spinal cord, brain, or both.
Autonomic function involves both sensory and motor fibers that help regulate our autonomic nervous system. These sympathetic and parasympathetic responses allow us to adapt and respond to our environment while we try to maintain a steady internal state.
Neurons in the peripheral nervous system may be classified as small- and large-fiber neurons, which refers to their diameter and whether they are myelinated.
Large-fiber neurons are myelinated, so their impulses travel quicker than the small-fiber neurons. Motor neurons that carry messages to muscles are large-fiber neurons. Sensory neurons that carry messages about position in space, vibration, and touch are also large-fiber neurons.
Small-fiber neurons carry sensory messages about damage (nociception) and temperature. Some autonomic motor messages are also carried via small-fiber neurons. These messages control sweating, blood pressure, GI tract activity, and other autonomic functions.
CIPN Pathophysiology
CIPN can develop with several different classes of chemotherapy agents, and the nerve damage can take several different forms. Unfortunately, depending on the type of cancer, the most effective chemotherapy drugs are often the most neurotoxic. Neuron damage can involve microtubule disruption (these are the organelles that deliver molecules through the long axons of peripheral nervous system neurons); oxidative stress that accompanies mitochondrial damage; and changes to the function of ion channels along the cell membranes, damage to myelin sheaths, and neuroinflammation, among other issues.
CIPN can develop with a single treatment of a specific drug, or it can develop over time as a chemotherapy treatment course progresses. CIPN can be severe enough that patients need to delay their treatment while they recover, and, of course, this may have negative consequences for patient outcomes. But perhaps the most insidious aspect of CIPN is that, for many patients, it only develops after their chemo has concluded—and then continues to get worse for weeks, months, or longer.
CIPN is extremely resistant to treatment with conventional interventions. This means a lot of cancer patients successfully conclude their treatment, which is great, but they now have a long-term, sometimes permanent, challenge with nerve damage.
CIPN Symptoms
CIPN symptoms can include any combination of problems with sensation, motor control, and autonomic function. However, sensory problems are the most commonly reported symptom.
Some versions of CIPN appear to target small-fiber neurons, while others target large-fiber neurons, and some affect both. The symptoms patients experience reflect what kinds of neurons have been affected.
Damage to large-fiber neurons can affect motor function, where reflexes may be slowed. And impaired large-fiber sensation feels like the person is always wearing thick gloves or socks. Perception from the skin is dulled and imprecise, and it is difficult to perform fine motor skills like buttoning a shirt or picking up coins if sensation is muffled in this way. And because proprioceptors may also be affected, the sense of position in space may be altered, which raises the risk for falls.
Damage to small-fiber sensory neurons can change the way temperature is interpreted (it could be hyper- or hyposensitive). Nociception may be accentuated, and signals can occur without any stimulus, which is called spurious sensation. Allodynia, the experience of pain even with the lightest stimulus of any kind, can arise from small-fiber damage. And if agents of the autonomic nervous system are affected, then the patient may develop intolerance to heat, excessive sweating, gastrointestinal symptoms, and problems with the regulation of blood pressure.
CIPN and Massage—and What the Research Says
My recommendation for working with clients dealing with cancer and the consequences of cancer treatment is to seek out advanced education to be knowledgeable enough to offer safe and effective massage therapy to this population.
As we consider potential risks and benefits for massage therapy in the context of a client who is living with CIPN, a few variables are important to pin down. We need to know what they are treating with their chemotherapy, and at what stage of their treatment they are. We need to know what other complications of their cancer or cancer treatments might be present. And we need to know how their CIPN affects them—with the understanding that symptoms can change from one day to the next.
Once we have managed the possible risks, which may include suppressed immunity, bone and organ involvement, and several other issues, we can think about what kind of touch might be most supportive and helpful. This is where it gets really interesting.
As we mentioned, one of the challenges with CIPN is that it doesn’t respond well to most treatment interventions. And because it can be severe enough to require that a chemotherapy regimen be interrupted, it can put patients at risk for poorer outcomes. If only there were a way to deal with CIPN that was gentle, safe, and well-accepted by patients . . .
I have some good news! A handful of small-scale studies, including case reports and clinical trials, suggest that skilled massage therapy could have a positive impact on CIPN, both as a treatment and, interestingly, as a possible preventive measure. Following is a brief overview of some of the studies I found most interesting, but others are provided in the resource list.
Case Report: Patient with CIPN Treated with Manual Therapy (Massage)1
This case report, which was a winner in the Massage Therapy Foundation Case Report Contest, is about a massage therapist whose client had moderate CIPN that was reduced to mild, along with improvements in quality of life and objective changes in the temperature of their extremities, after a course of massage therapy. The report gives some nice descriptions of the sessions that could be helpful to other massage therapists.
Prevention of CIPN with Classical Massage in Breast Cancer Patients Receiving Paclitaxel: An Assessor-Blinded Randomized Controlled Trial2
In this clinical trial, 40 women with breast cancer were randomized to an experimental group or control group before they started chemotherapy, to track whether massage might make a difference. The control group had predictable accumulation of symptoms over time, but the massage group did not. This led the researchers to suggest that massage therapy could be used as a preventive measure, if it can be provided before chemotherapy treatments begin. (Note: This synopsis is accurate but very simplified; this extremely complex project had several other interesting findings.)
Healing Hands: Massage Therapy Can Offer Relief for CIPN Symptoms3
This review of an abstract presented at the 2016 Palliative Care in Oncology Symposium describes a study in which 62 patients participated to look at massage for cancer patients with CIPN. The results varied, depending on the specific CIPN symptom. Little change was found in symptoms that involved buzzing or ringing in the ears, but overall weakness, numbness, and tingling in the feet—as well as difficulty walking—were all substantially improved. Further, of those who enrolled in the study who didn’t already have CIPN, 97 percent remained pain-free. This study lacked a control group for comparison, but it certainly points to some interesting possibilities.
A Thought to Consider . . . and Some Takeaways
It seems reasonable to suggest, based on the research, that careful, skilled massage therapy may be a viable option for at least some people with CIPN. Massage might also make some patients’ cancer treatment more tolerable, leading to better outcomes.
But how does it work? Massage is unlikely to undo the damage caused by neurotoxic medication—that nerve damage can be permanent, with long-term impairment and signs of inflammation in both central and peripheral systems—but I am curious about whether CIPN, especially when it persists for months and years after cancer treatment is finished, might be connected to another chronic pain pattern: central sensitization.
In central sensitization, aspects of the CNS physically change. We grow new sensory dendrites, and we secrete different neurotransmitters, and these changes make us more likely sensitized to interpret incoming signals as pain. In short, being in pain makes someone with central sensitization more likely to experience more pain: It becomes a self-fulfilling prophecy.
I was unable to find any research that links long-term CIPN directly to central sensitization, but I did find a study that looked at connections between diabetic neuropathy and this CNS overreaction to incoming signals. This makes me wonder if CIPN might have some aspects of central sensitization as well.
This possible connection between CIPN and the CNS is interesting to contemplate because we know that skillful manual therapy, including various forms of massage, turns out to be helpful for some situations where central sensitization has ingrained the experience of pain. Our work, with its impact on physical, mental, and emotional well-being, is especially suited for people who live with chronic, intractable pain. We can, through welcomed and educated touch, help “turn down the volume” on central sensitization, which, along with other self-help strategies, can make the whole experience more manageable.
Will massage therapy solve the problem of CIPN for all patients? Almost certainly not. But with skill, sensitivity, and curiosity, we might be able to lessen this problem for many patients. And that is worth pursuing.
Notes
1. Joan Elizabeth Cunningham et al., “Case Report of a Patient with Chemotherapy-Induced Peripheral Neuropathy Treated with Manual Therapy (Massage),” Supportive Care in Cancer 19, no. 9 (July 2011): 1,473–76, https://doi.org/10.1007/s00520-011-1231-8.
2. Nur Izgu et al., “Prevention of Chemotherapy-Induced Peripheral Neuropathy with Classical Massage in Breast Cancer Patients Receiving Paclitaxel: An Assessor-Blinded Randomized Controlled Trial,” European Journal of Oncology Nursing 40 (March 2019): 36–43, https://doi.org/10.1016/j.ejon.2019.03.002.
3. Allie Casey, “Healing Hands: Massage Therapy Can Offer Relief for CIPN Symptoms,” Oncology Nursing News (September 17, 2016), www.oncnursingnews.com/view/healing-hands-massage-therapy-can-offer-relief-for-cipn-symptoms.
Ruth Werner is a former massage therapist, a writer, and an NCBTMB-approved continuing education provider. She wrote A Massage Therapist’s Guide to Pathology (available at booksofdiscovery.com), now in its seventh edition, which is used in massage schools worldwide. Werner is also the host of the podcast I Have a Client Who . . . on The ABMP Podcast Network. She is available at ruthwerner.com or wernerworkshops@ruthwerner.com.