Auricular Point Acupressure: Examining the Scientific Underpinnings of Pain Relief

Chemotherapy-induced peripheral neuropathy (CIPN)-numbness, burning and stunning pain distributed in hands and feet-is a major challenge among cancer patients. Even after completion of chemotherapy, CIPN persists among ~30-40% of cancer patients, which can negatively impact quality of life. The only drug (duloxetine) better than placebo in a randomized control trial improved pain intensity by 0.72 points on a scale of 0-10, which cannot manage CIPN effectively. A better pain management strategy clearly needs to be developed.

The investigators propose to test auricular point acupressure (APA), a non-invasive, easily administered, patient-controlled, and non-pharmacological strategy, to provide rapid, safe, and effective pain relief so that cancer patients can self-manage their CIPN. APA involves an acupuncture-like stimulation of the ear without needles. With APA, small seeds are taped to specific ear points. The patient is taught to apply pressure to the seeds, with the thumb and index finger, three times a day (morning, noon, and evening) for three minutes each session to achieve pain relief. The investigators have developed a detailed APA protocol to teach health-care providers without experience in acupuncture and traditional Chinese Medicine that investigators can learn about APA in brief educational seminars as a treatment including the systematic identification of ear points (called auricular diagnosis). The investigators teach methods that enable patients to continue using APA to self-manage their pain. However APA is not available in current U.S. health care setting yet.

Quantitative sensory testing (QST) and fMRI in acupuncture have provided new objective methods for measuring pain. QST provides an evaluation of peripheral and central mechanisms of pain by quantifying stimulus-evoked negative and positive sensory phenomena to evaluate a participant's perception of threshold values regarding pain generated through touch (A beta fibers), warmth (C fibers), cold (A delta fibers), and heat (C fibers). Studies have demonstrated changes in heat, pressure, and mechanical pain thresholds immediately following acupuncture; however no study in APA yet. Brain imaging studies in acupuncture indicate that acupuncture can restore normal functional connectivity related to pain reduction. In conjunction with the investigators pilot data demonstrating that APA impacts neural-immune signaling in patients with chronic low back pain, the investigators hypothesize that APA may likewise induce pain relief through the stimulation of A beta fibers and/or C fibers to increase the pain threshold, endogenous opioid binding (releasing inflammatory cytokines), and alter brain networks of central processing in the hypothalamic-pituitary-adrenocortical axis to achieve analgesia.

The investigators plan to study the mechanisms underpinning pain sensitivity and pain processing due to APA on CIPN. Along with the clinical and subjective CIPN outcomes, objective outcomes will include physiological change in pain sensory thresholds (measured by quantitative sensory testing), brain change associated with pain processing (measured by fMRI), and neuro-transmitters (measured by inflammatory cytokines).