Alterations in resting‐state regional cerebral blood flow demonstrate ongoing pain in osteoarthritis: An arterial spin‐labeled magnetic resonance imaging study

Abstract

Objective. Increasing evidence suggests a central nervous system (CNS) component underpinning persistent pain disease states. This study was undertaken to determine regional cerebral blood flow (rCBF) changes representing ongoing pain experienced by patients with painful osteoarthritis (OA) of the carpometacarpal (CMC) joint and to examine rCBF variability across sessions. We used pulsed continuous arterial spin labeling (pCASL), a perfusion magnetic resonance imaging (MRI) technique.Methods. The study included 16 patients with CMC OA and 17 matched controls. Two pCASL scans and numerical rating scale (NRS) estimates of ongoing pain were acquired in each of two identical sessions. Voxelwise general linear model analyses were performed to determine rCBF differences between OA and control groups, rCBF differences between sessions within each group, and whether sessionwise rCBF differences were related to variability in perceived ongoing pain.Results. In the OA group, rCBF increases representing ongoing pain were identified in the primary and secondary somatosensory, insula, and cingulate cortices; thalamus; amygdala; hippocampus; and dorsal midbrain/pontine tegmentum, including the periaqueductal gray/nucleus cuneiformis. Sessionwise rCBF differences in the OA group in the postcentral, rostral/ subgenual cingulate, mid/anterior insula, prefrontal, and premotor cortices were related to changes in perceived ongoing pain. No significant sessionwise rCBF differences were observed in controls.Conclusion. This is the first quantitative endogenous perfusion MRI study of the cerebral representation of ongoing, persistent pain due to OA. Observed rCBF changes potentially indicate dysregulated CNS appraisal and modulation of pain, most likely the maladaptive neuroplastic sequelae of living with painful OA. Understanding the neural basis of ongoing pain is likely to be important in developing novel treatment strategies.Persistent pain is a major health care problem. As many as 100 million people in Europe alone experience an intractable, ongoing malaise that affects quality of life, places an increasing burden on health care resources, and costs the economy in excess of €50 billion every year (1). While multidisciplinary pain management strategies help patients cope (2), there is a recognized, unmet need for the development of novel, more

Acupuncture modulates cortical thickness and functional connectivity in knee osteoarthritis patients

“…The MPFC/rACC (including the pre-genual and sub-genual ACC) is a key region involved in the descending pain modulatory system6887888990. Studies also have shown that in knee OA patients, the lateral prefrontal cortex, the rACC, the bilateral insula, the parietal operculum, and the limbic cortical areas are involved in altered pain processing in OA791. This suggests that the MPFC/rACC is a main area involved in the OA pain circuit.…”

“…Previous studies have demonstrated central sensitization in osteoarthritis patients456, increased activity in the periaqueductal grey (PAG) matter associated with stimulation of the skin in referred pain areas of patients6, and increased regional cerebral blood flow (rCBF) in pain related brain regions including the primary and secondary somatosensory, insula, cingulate cortices, thalamus, amygdala, hippocampus and PAG7, indicating pathology of the central nervous system in knee OA patients.…”

Using arterial spin labelling to investigate spontaneous and evoked ongoing musculoskeletal pain

“…Increase in perfusion in primary and secondary somatosensory cortex, mid-insula, amygdala, hippocampus, and midbrain was reported in an ASL study on osteoarthritis 19 In another ASL study on pain in peer-reviewed) is the author/funder. All rights reserved.…”

“…Thirdly, it had the advantage of using both within-and between-subject analyses, which helped with the interpretation of the observed results. Moreover, the sample size in this study was two to three times larger than the previous ASL patient studies 6,3,19 . Finally, we used an optimised registration between the ASL and the structural space.…”

Neuroimaging mechanisms in pain: from discovery to translation

“…1,19,21,26,60,89,138 A number of important ASL/pain studies have been conducted by colleagues and us over the past few years. 55,56,71,84,[90][91][92]101,104,106 In a recent study published by our group, we performed the paradigm in a slightly different manner using an advanced acquisition ASL method and identified a fundamental role for the contralateral dorsal posterior insula in tracking ongoing pain. 99 What was different about our study is that we explicitly determined what brain regions over a long period are continuously activate and track a specific feature of the pain experience (intensity) in response to a controlled manipulation of the nociceptive input.…”