The Preliminary Effectiveness of Auricular Point Acupressure on Chemotherapy-Induced Neuropathy: Outcomes of the Sensory Function

Purpose:

1. Introduction:Approximately 64% of cancer patients develop chemotherapy-induced neuropathy (CIN), which is predominantly characterized by numbness, burning and stunning pain distributed in hands and feet. Up to 68% of patients still suffer from CIN even after completion of chemotherapy. CIN produces persistent symptoms affecting sensation and balance in cancer survivors, which can negatively impact their functional status and quality of life. limited effectiveness of CIN therapy highlight the critical need to manage CIN. Nonetheless, no effective treatment for CIN has been established. Auricular point acupressure (APA) is a non-invasive, non-pharmacological, patient-managed strategy, which involves the seeds have been taped on the patient’s ear by the provider, the patient is able to manage their treatment by themselves at home. Based on the conceptual framework of APA to reduce CIN symptoms.
2. Purpose:This study aims to examine the effectiveness of APA to reduce CIN and compare the changes in sensory function.

Methods:

1. A quasi-experimental study was conducted to examine the feasibility of a 4-week APA intervention to manage CIN. After consent was obtained and baseline (hereafter, control, T0) data were collected, participants waited a month and then completed the same data questionnaire before they started receiving a 4-week APA intervention.
2. Outcomes were assessed at baseline (T0), pre-intervention (T1), once a week for the 4 weeks of APA treatment (T2, T3, and T4), after the 4-week APA treatment (T5), and at 1-month follow-up (T6).
3. Measuring the sensory function by the QST(Quantitative sensory testing), which is consisted of (1) mechanical QST ,(2) pressure pain threshold(PPT) ,(3) Grip and Pinch Strength.Mechanical QST tests have two different parameters: mechanical detection threshold(also called Light touch sensation) and mechanical pain threshold(MPT). light touch sensation was measured by Semmes-Weinstein Monofilament tests (SWMT) to examine cutaneous sensation threshold levels of the foot, using Touch-Test Sensory Evaluators six Piece Foot Kit. MPT was measured by Weighted PinPrick stimulators to measure cutaneous sensation threshold on the hand. A digital force gauge was used to determine the PPT in the trapezius and thumb (distal interphalangeal joints) areas on both sides of the body. Grip and Pinch Strength was assessed via hand and grip and pinch strength were assessed using a hand dynamometer and digital pinch gauge.

Intervation:

1. The researcher demonstrated the pressing technique to the participants, instructing them to apply steady pressure on the taped seeds until either mild discomfort or tingling was felt.
2. Participants were instructed to evenly press the tape and seeds covering each ear point without rubbing (to avoid skin damage and infection at the acupressure point) for 3 minutes per time, three times daily (9 minutes total), even if they did not experience pain. A 2-second pause occurred between the two pressings. Participants were instructed to remove both tape/seeds at the end of the 5th day, and 2 days without. The treatment duration was 4 weeks with weekly cycles. Each weekly cycle included one visit.

Results:

1. Fifteen participants participated, but two dropped out due to new medical reasons after they received the first APA treatment. Data from 13 participants (mean age 20 ± 7.95) were used for analysis.
2. Light touch sensation. Compared to pre-APA, the mean score of monofilaments for each tested site all decreased. At the two dorsal sites tested on the foot, the mean percentage change was 25% in first metacarpophalangeal joint and 21% in dorsum medial navicular, respectively. On the plantar side of the foot, the first metacarpophalangeal joint had the largest decreased score (29%) at post-APA. In general, the effects of APA on both feet were sustained at 1-month follow-up.
3. Mechanical pain threshold (MPT). The suprathreshold pinprick stimuli mean scores were increased from pre- to post-APA, except the scores from the index finger and thumb. After 4-week APA, the mean percentage change scores decreased by 19% at dorsum, 18% at hypothenar, and 5% at the pad of the middle finger, respectively, when compared with pre-APA intervention.
4. Pressure pain thresholds (PPT). The pressure pain thresholds for thumb and trapezius increased after 4 weeks of APA. The effects of APA lasted at 1-month follow-up.
5. Grip and Pinch Strength. The grip strength increased after 4 weeks of APA, which was sustained at 1-month follow-up. Pinch tests increased after 4-weeks of APA and continued to improve at 1-month follow-up.

Conclusion:

1. The study findings indicate that the use of APA to manage CIN is promising. After 4 weeks of APA, CIN patients showed improved sensation in their lower extremity, improve pain threshold on their upper extremity, increased pressure pain thresholds and increased grip strength as well as pinch strength.
2. APA may activate neuronal signaling at the periphery and central nervous system. Based on SWMT findings, the lower extremity testing sites appear to regain sensory discrimination after the first week of APA (data from weekly assessments) and after 4 weeks of APA, and at 1month follow-up, indicating that APA may reduce numbness, a prime characteristic of neuropathic pain.
3. APA may provide an inexpensive and effective complementary approach for the management of CIN. The characteristics of time-efficiency, active participation, and potential for immediate pain relief from APA provides patients with a greater sense of control over their pain/symptoms, allowing them to resume daily tasks that CIN has prevented them from doing. Teaching patients the skills necessary for APA practice can be completed within 15 minutes.
4. In the future, we envision teaching patients and/or their caregivers how to do APA treatments in their entirety ,and evaluating the effectiveness of this eminently scalable approach.