Our knowledge of central sensitization (CS) in chronic low back pain (CLBP) is limited. 2011 fibromyalgia criteria and severity scales (2011 FM survey) have been used to determine FM positive as a surrogate of CS. The major features of CS including widespread hyperalgesia and dysfunction of the descending inhibitory pathways can be identified by pressure pain threshold (PPT) and conditioned pain modulation (CPM) tests. The purpose of the study was to examine neurophysiological characteristics and psychosocial symptoms in a subgroup of FM-positive CLBP compared with FM-negative CLBP patients.
A total of 46 participants with CLBP and 22 pain-free controls completed outcome measures of the 2011 FM survey, PPT and CPM tests, and psychosocial questionnaires. Differences between FM-positive and FM-negative CLBP participants on these measures and correlations were analyzed.
The 2011 FM survey identified 22 (48%) participants with CLBP as FM positive. FM-positive CLBP participants showed lower PPT values of the thumbnail (P=0.011) and lower back (P=0.003), lower CPM values of the thumbnail (P=0.002), and more severe pain catastrophizing, anxiety, and depression symptoms (P<0.05) than FM-negative CLBP participants. The 2011 FM scores were significantly correlated with the PPT and CPM values of the thumbnail and with psychosocial symptoms (P<0.001).
Our findings suggest a subgroup of CLBP patients exhibiting with signs and symptoms of CS. Associations between subjective and objective CS measures indicate that the 2011 FM survey can be utilized to identify the presence of CS in CLBP in clinical practice.
Departments of *Physical Therapy and Rehabilitation Science
†Biostatistics and Data Science
‡Anesthesiology, University of Kansas Medical Center, Kansas City, KS
§Department of Anesthesiology, University of Michigan Medical School, Ann Arbor, MI
K.A., D.J.C., and N.K.S.: study concept, design, and protocol development. K.A.: data collection and statistical analyses. K.A., J.H., and N.K.S.: interpretation of the data and drafting of the manuscript. All authors were involved in discussion of the results, revising the drafts, and final approval of the manuscript.
Partially supported by the T32 Program (T32HD057850; PI: Randolph Nudo) to Andrew Doyle and Jacquelyne Vaughan and by the Department of Physical Therapy and Rehabilitation Science to N.K.S. A.L.N. has received research funding from National Institute of General Medical Sciences of the National Institutes of Health (NIH #K23GM123320) and served as a consultant for Heron Therapeutics and on an advisory board of Sandoz International. The remaining authors declare no conflict of interest.
Reprints: Neena K. Sharma, PT, PhD, Department of Physical Therapy and Rehabilitation Science, University of Kansas Medical Center, 3901 Rainbow Boulevard, Kansas City, KS 66160 (e-mail: firstname.lastname@example.org).
Received March 13, 2019
Received in revised form June 13, 2019
Accepted July 27, 2019
Online date: August 12, 2019