Cortical thickness and functional connectivity abnormality in chronic headache and low back pain patients

Abstract

This study aims to characterize the psychological wellbeing of chronic headache (CH) patients, to identify cortical structural abnormalities and any associations of those abnormalities with resting state functional connectivity (rsFC), and to determine whether such rsFC abnormality is specific to CH patients. Compared with healthy controls (CON ), CH patients suffered from mild depression, sleep disturbances, and relatively poor quality of life. CH patients also exhibited widespread cortical thickness (CT) abnormalities in left premotor (BA6), right primary somatosensory (S1) and right prefrontal (BA10) cortices, as well as in regions of default mode and executive control networks. Using cortical regions with thickness abnormality as seeds, we found cortical region pairs showed strengthened rsFC in CH patients. Using the same seeds, rsFC analysis from chronic low back pain (CLBP) patients and their controls (CON ) identified abnormalities in non-overlapping cortical region pairs. Direct comparison of rsFC between CH and CLBP patients revealed significantly differences in thirteen cortical region pairs, including the four identified in CH and CON comparison. Across all three groups (CH, CLBP and CON), the rsFC between left multisensory association area (BA39) and left posterior cingulate cortex (BA23) differed significantly. Eight regions showed CT abnormality in CLBP patients, two of which overlapped with those of CH patients. Our observations support the notion that CH and CLBP pain are pathological conditions, under which the brain develops distinct widespread structural and functional abnormalities. CH and CLBP groups share some similar structural abnormalities, but rsFC abnormalities in several cortical region pairs appear to be pathology-specific. Hum Brain Mapp 38:1815-1832, 2017. © 2017 Wiley Periodicals, Inc.

Correlated Disruption of Resting-State fMRI, LFP, and Spike Connectivity between Area 3b and S2 following Spinal Cord Injury in Monkeys

“…Extracellular recording and analysis. We identified area 3b, S2, and interareal borders by using fMRI map, electrode mapping, and vasculature pattern as guides, and based on the known characteristics of receptive field properties, preferred stimuli, and somatotopic organization of the digits, hand, and arm (Kaas et al, 1984;Jain et al, 2008;Wang et al, 2013). Detailed surgical procedures were described previously (Chen et al, 2001; Reed et al, 2008; Wang et al, 2013).…”

“…6C). We used 10 ms as the bin width with reference to previous studies under similar experimental conditions (Reed et al, 2008(Reed et al, , 2012Wang et al, 2013). Percentages of spiking rate changes were calculated by subtracting and then dividing the baseline spiking rate at resting state.…”

“…Our recent discoveries of dynamic functional organization in somatic areas 3b, 1, and secondary somatosensory cortex (S2) and significantly altered weakened horn-to-horn rsFC in injured spinal cord gray matter, and its recovery over time underscored the behavioral significance of changes in region-to-region rsFC . Previous studies have demonstrated strong correlative relationships between electrophysiological and BOLD signals under processing of sensory inputs (Logothetis et al, 2001;Mukamel et al, 2005;Ekstrom, 2010;Wang et al, 2013).…”

“…Since the discovery of highly correlated fluctuations of restingstate fMRI (rsfMRI) signals between distant brain regions, it has been widely used as an indicator of intrinsic interareal functional connectivity (FC) (Biswal et al, 1995;Raichle, 2010). fMRI resting-state FC (rsFC) alterations have been proposed to be noninvasive and sensitive biomarkers for many pathological conditions, including schizophrenia, autism, stroke, and chronic pain (Rotarska-Jagiela et al, 2010;Wang et al, 2017;. rsFC has been widely used for probing functional circuit changes in clinical populations (Fox and Greicius, 2010).…”

The Dorsolateral Prefrontal Cortex in Acute and Chronic Pain

“…One study that contrasted brain resting cerebral blood flow between two chronic orofacial pain disorders, temporomandibular disorders and trigeminal neuropathic pain, found that both patient groups had increased DLPFC resting cerebral blood flow compared to pain-free controls, suggesting that spontaneous pain is related to DLPFC activity 111 . Other studies have reported lower gray matter volume (GMV) or thinner cortices in the DLPFC in patients with chronic pain, including irritable bowel syndrome 9, 90 , chronic low back pain 3, 85, 92, 110 , migraine 38 , trigeminal neuralgia 35, 66 , chronic post-traumatic headache 65 , and complex regional pain syndrome 26 . In some cases, these structural abnormalities were correlated with pain catastrophizing or other clinical characteristics 38 .…”