Skip to Main Content
Text size: SmallMediumLargeExtra-Large

Collaborative Research on the Transition From Acute to Chronic Pain: New Models and Measures in Clinical and Preclinical Pain Research

Molecular and Cellular Neuroscience Program
Integrative Biology and Infectious Diseases Branch
Division of Extramural Research
  

OBJECTIVE:
The objectives of this Initiative are to: 1) assemble research teams with expertise in basic and clinical pain research and related expertise outside the pain field that will provide novel, collaborative , multidisciplinary approaches to answer crucial questions about the transition from acute to chronic pain; 2) discover biological and behavioral mechanisms that drive the transition from an acute, protective pain state to a chronic dysfunctional pain condition; 3) develop new clinical and preclinical models and measures of pain that will be essential to identify and characterize these mechanisms. An understanding of the mechanisms and risk factors that determine who will transition to a chronic pain state is necessary in order to better prevent this transition and to design new, effective treatments to resolve acute pain before it becomes chronic.

 

BACKGROUND:
a)  Scope/magnitude of the problem
Pain conditions are a major health problem in the US and their economic burden approaches $100 billion per year in lost productivity and medical expenses. These conditions lead to medical morbidity and a reduced quality of life for millions of Americans. The NIDCR mission is committed to supporting research in temporomandibular joint disorders (TMJD) and other chronic orofacial pain conditions. It is estimated that TMJDs affect approximately 10 million individuals, the majority of them women during their childbearing age. Recent epidemiological data, collected as part of the NIH-sponsored Osteoarthritis Initiative, show that approximately 7% of individuals responding to questions about osteoarthritis pain, experienced pain in the jaw joint or in front of the ear during the 30-day period prior to the survey. An additional 3.3% experienced facial or cheek pain or aching during the same period. It is currently unclear how many individuals experiencing acute pain in the TMJ will develop a chronic, persistent pain condition. For the most part, acute TMJ pain resolves with no or minimal treatment. But for those that develop chronic TMJD lasting three months or longer, the effects can be debilitating and lead to a reduced quality of life. Some pain symptoms can be alleviated by analgesics but there are no effective treatments to completely resolve chronic TMJD or other chronic pain conditions. Some drugs that are used have unwanted side effects that limit their prolonged use or have a low response rate or reduced efficacy. Most current pharmaceutical and behavioral therapies for chronic pain conditions focus on the symptoms, but do not target the underlying mechanisms. Also, these therapies were developed and tested based on our understanding of acute pain mechanisms. None are targeted to prevent the transition to a chronic pain state. 

b)  Gaps in our knowledge
We currently have a relatively incomplete understanding of the etiology and pathology of chronic TMJDs and other chronic pain conditions. A largely unaddressed challenge is our lack of knowledge in determining who will transition to a chronic pain state and how to treat patients to prevent this transition. We need to understand, mechanistically, how pain changes from an acute, high threshold, protective response to a chronic, low threshold, and spontaneous dysfunctional condition. We do not fully understand how acute pain progresses to chronic pain at any level, from the molecular to behavioral.

Current preclinical and clinical models of pain do not replicate all aspects of human chronic pain states. Current measures of pain in both animals and humans usually rely on evoked responses and do not reflect the spontaneous and recurrent pain in chronic conditions. Most basic, preclinical research has focused on mechanisms, molecules, and circuitry involved in acute pain. This knowledge has then been applied to and validated in human studies. While this translational approach is important, little reverse translation has occurred in the pain field, where mechanistic and observational studies in humans are designed to inform animal research in order to validate and examine in more detail the mechanisms underlying pain. Knowledge gained through a combination of human and animal model studies will improve the development of therapeutic approaches for chronic pain conditions.

The unmet need here is the effective prevention and treatment of chronic pain conditions. In order to begin to meet this need, an emphasis on research at the transition from acute to chronic pain is needed to understand how neurophysiological changes during this period of time lead to chronic pain. In addition, new clinical and preclinical models of pain conditions and new measures of pain designed to better reflect chronic human pain conditions are needed. These measures call for objective, non-invasive, functional approaches and might include brain imaging and biobehavioral assessments. By changing the research focus and providing new tools to study pain, we will be able to predict who is at risk of developing chronic pain conditions and to develop novel therapies to prevent the transition to chronicity.

 

 

 

 

     

 

 

Share This Page

GooglePlusExternal link – please review our disclaimer

LinkedInExternal link – please review our disclaimer

Print

This page last updated: February 26, 2014