The journal of pain : official journal of the American Pain Society
-
Pain sensitivity is characterized by interindividual variability, determined by factors including genetic variation of nociceptive receptors and pathways. The sigma-1 receptor (SIGMAR1) is involved in pain modulation especially under pre-sensitized conditions. However, the contribution of SIGMAR1 genetic variants to pain generation and sensitivity is unknown yet. ⋯ This study indicates lack of association of SIGMAR1 -297G>T and 5A>C genetic variants to susceptibility to develop chronic pain, but significant modulation of somatosensory function in neuropathic pain patients. PERSPECTIVE: This article presents the first study indicating a modulation of somatosensory function in neuropathic pain patients by selected genetic variants in SIGMAR1. As our findings could contribute to the explanation of interindividual differences in drug response they might help to improve the treatment of neuropathic pain.
-
Differences in neural drive could explain variation in adaptation to acute pain between postural and voluntary motor actions. We investigated whether cortical contributions, quantified by corticomuscular coherence, are affected differently by acute experimental pain in more posturally focused position-control tasks and voluntary focused force-control tasks. Seventeen participants performed position- and force-control contractions with matched loads (10% maximum voluntary contraction) before and during pain (injection of hypertonic saline into the infrapatellar fat pad of the knee). ⋯ PERSPECTIVE: Understanding of the mechanisms underlying adaptations to motor function in acute pain is incomplete. Experimental work almost exclusively focuses on voluntary motor actions, but these adaptations may be inappropriate for postural actions. Our results show less pain-related interference in brain activity and its relationship to muscle activation during position-control tasks.
-
Chronic pain is a prevalent and costly condition, with many patients receiving income support and funded treatment. Given that pain cannot be assessed objectively, patients may be suspected of exaggerating their pain and disability to receive additional funding. Although numerous methods of detecting malingering have been suggested, it is unclear whether clinicians can reliably identify malingering in patients with chronic pain. ⋯ Perspective: There is interest in the development of assessment tools to detect malingering in patients with chronic pain. An evaluation of methods reveals theoretical and empirical limitations that undermine the usefulness of these approaches. As yet, there is no reliable way for clinicians to identify malingering in patients with chronic pain.
-
The multidimensional nature of chronic pain is not reflected by definitions based solely on pain duration, resulting in high prevalence estimates limiting effective policy development. The newly proposed concept of high-impact chronic pain (HICP) incorporates both disability and pain duration to identify a more severely impacted portion of the chronic pain population yet remains uncharacterized at the population level. As such, we used the 2011 National Health Interview Survey (N = 15,670) to 1) assess the likelihood of disability in the overall chronic pain population, 2) estimate the prevalence of HICP, and 3) characterize the disability, health status, and health care use profile of this population in the United States. ⋯ Understanding this heterogeneity will contribute to developing more effective legislation promoting safe and cost-effective approaches to the prevention and treatment of chronic pain. PERSPECTIVE: HICP is a powerful new classification that differentiates those with debilitating chronic pain from those with less impactful chronic pain. By addressing the multidimensionality of chronic pain, this classification will improve clinical practice, research, and the development of effective health policy.
-
Prescription opioid misuse is a serious public health concern, yet antecedent factors are poorly described. Using data from the National Longitudinal Study of Adolescent to Adult Health (N = 14,784), we examined the longitudinal relationship between a history of adolescent chronic pain and the odds of misusing prescription opioids in adulthood. The primary predictor variable was chronic pain status during adolescence. ⋯ Longitudinal associations between adolescent chronic pain and subsequent adult prescription opioid misuse highlight the need for early targeted screening and prevention efforts that may reduce later opioid misuse. Perspective: Using a large, nationally representative sample, we found that chronic pain during adolescence was an independent risk factor for opioid misuse in adulthood, over and above other known risk factors. Furthermore, among those individuals with adolescent chronic pain, substance use, exposure to trauma, and race were associated with opioid misuse.