Numbness associated with neuropathic pain suggests the loss of function in myelinated, large diameter sensory neurons. The purpose of this study was to examine the relationships between pain severity and subjective (ie, severity of numbness) and objective (ie, loss of light touch sensations, vibration thresholds) measures of loss of large fiber function in adult survivors with chemotherapy-induced peripheral neuropathy (CIPN, n=426) and breast cancer patients with persistent postsurgical pain (n=80).
For both samples, average pain and numbness were evaluated using a 0 to 10 numeric rating scale. Loss of light touch sensations in the hands and feet of patients with CIPN and in the upper arm of patients at 5 and 6 months following breast cancer surgery were assessed using Semmes Weinstein monofilaments. Loss of vibration in the hands and feet of patients with CIPN was assessed using a biothesiometer. Pearson Product Moment correlation coefficients were calculated between average pain and the number or percentage of sites with loss of light touch sensations, mean vibration thresholds, and the severity of numbness.
For both pain conditions, average pain scores were significantly correlated with objective measures of large fiber function (r=0.12 to 0.34; all P<0.05) and numbness (r=0.22 to 0.52; all P<0.008).
Our findings, in 2 independent samples of oncology patients, suggest that loss of function of myelinated, large diameter fibers contributes to the severity of neuropathic pain.
*School of Nursing
†School of Medicine
#School of Dentistry, University of California, San Francisco, CA
‡School of Nursing, University of Pittsburgh, Pittsburgh, PA
§Department of Nursing, Mount Sinai Hospital, New York, NY
∥Boston Children’s Hospital
¶Harvard Medical School, Boston, MA
The contents are solely the responsibility of the authors and do not necessarily represent the official views of the NIH. Recruitment was facilitated by Dr. Susan Love Research Foundation’s Army of Women Program.
Supported by grants from the National Cancer Institute (NCI, CA151692, CA107091, CA118658). C.M. is supported by a grant from the American Cancer Society and NCI (CA168960). This project was supported by the National Center for Advancing Translational Sciences, National Institutes of Health, through UCSF-CTSI Grant Number UL1 TR000004. The authors declare no conflict of interest.
Reprints: Christine Miaskowski, RN, PhD, Department of Physiological Nursing, University of California, 2 Koret Way—N631Y, San Francisco, CA 94143-0610 (e-mail: email@example.com).
Received February 22, 2018
Received in revised form July 25, 2018
Accepted August 29, 2018