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Original Research ARTICLE Provisionally accepted The full-text will be published soon. Notify me

Front. Hum. Neurosci. | doi: 10.3389/fnhum.2019.00174

Network alterations in comorbid chronic pain and opioid addiction: an exploratory approach

  • 1National Institute of Neurological Disorders and Stroke (NINDS), United States
  • 2College of Education, Texas State University, United States
  • 3Department of Communication Sciences and Disorders, College of Health and Human Services, University of New Hampshire, United States
  • 4Department of Psychiatry, University of Texas Health Science Center at San Antonio, United States
  • 5College of Nursing, Ohio State University, United States
  • 6Department of Health Management and Policy, College of Health and Human Services, University of New Hampshire, United States
  • 7University of New Hampshire, United States

The comorbidity of chronic pain and opioid addiction is a serious problem that has been growing with the practice of prescribing opioids for chronic pain. Neuroimaging research has shown that chronic pain and opioid dependence both affect brain structure and function, but this is the first study to evaluate the neurophysiological alterations in patients with comorbid chronic pain and addiction. Eighteen participants with chronic low back pain and opioid addiction were compared with eighteen age- and sex-matched healthy individuals in a pain-induction fMRI task. Unified structural equation modeling (SEM) with Lagrange multiplier (LM) testing yielded a network model of pain processing for patient and control groups based on 19 a priori defined regions. Tests of differences between groups on specific regression parameters were determined on a path-by-path basis using z-tests corrected for the number of comparisons. Patients with the chronic pain and addiction comorbidity had increased connection strengths; many of these connections were interhemispheric and spanned regions involved in sensory, affective, and cognitive processes. The affected regions included those that are commonly altered in chronic pain or addiction alone, indicating that this comorbidity manifests with neurological symptoms of both disorders. Understanding the neural mechanisms involved in the comorbidity is crucial to finding a comprehensive treatment, rather than treating the symptoms individually.

Keywords: Chronic low back pain, opioid addiction, fMRI, Pain induction, unified structural equation modeling, vector autoregressive modeling, automated search strategy

Received: 18 Jan 2019; Accepted: 13 May 2019.

Edited by:

Alexander M. Baldacchino, University of St Andrews, United Kingdom

Reviewed by:

Jane E. Joseph, Medical University of South Carolina, United States
Gianluca Coppola, Fondazione G.B. Bietti (IRCCS), Italy  

Copyright: © 2019 Smallwood, Price, Campbell, Garrett, Atalla, Monroe, Aytur, Potter and Robin. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

* Correspondence: Dr. Donald A. Robin, Department of Communication Sciences and Disorders, College of Health and Human Services, University of New Hampshire, Durham, United States,