Exposure in vivo Induced Changes in Neural Circuitry for Pain-Related Fear: A Longitudinal fMRI Study in Chronic Low Back Pain

Abstract

Exposure in vivo (EXP) is a cognitive-behavioral treatment aimed at reducing pain-related fear in chronic pain, and has proven successful in reducing pain-related disability in patients with chronic low back pain (cLBP). The current longitudinal study aimed to reveal the neural correlates of changes in pain-related fear as a result of EXP. Twenty-three patients with cLBP were included in this study. Patients with cLBP underwent MRI scanning pre-treatment (pre-EXP), post-treatment (post-EXP), and 6 months after end of treatment (FU-EXP). Pain-free controls were scanned at two time points. In the scanner, participants were presented with pictures involving back-related movements, evoking pain-related fear in patients. Pre-treatment, functional MRI revealed increased activation in right posterior insula and increased deactivation in medial prefrontal cortex (mPFC) in patients compared to controls. Post-treatment, patients reported reduced fear and pre-EXP group differences were no longer present. Contrasting pre- to post- and FU-EXP in patients revealed that stimulus-evoked neural responses changed in sensorimotor as well as cognitive/affective brain regions. Lastly, exploratory analyses revealed a tendency toward an association between changes in neural activation and changes in fear ratings, including the hippocampus and temporal lobe (pre- to post-EXP changes), and mPFC and posterior cingulate cortex (pre- to FU-EXP changes). Taken together, we show evidence that neural circuitry for pain-related fear is modulated by EXP, and that changes are associated with self-reported decreases in pain-related fear.

Pain Catastrophizing Is Related to Static Postural Control Impairment in Patients with Nonspecific Chronic Low Back Pain: A Cross-Sectional Study

“…e interrupted visual information was detrimental to postural control in older adults [24] which increased the risk of falls in older adults to perform the balance test with eyes closed. is was also consistent with published studies which excluded adults who aged above 65 years old [25,26]. e study also imposed the criteria to include only right-handed participants only.…”

Fear avoidance beliefs limit lumbar spine flexion during object lifting in pain-free adults

“…In support of this notion recent evidence indicates an implicit bias towards “lifting with a flexed spine is dangerous”, compared to lifting with a neutral spine, in patients with persistent LBP as well as in the pain-free individuals [5,6]. Brain research further supports this by demonstrating distinct relationships between self-reports of pain-related fear and fear-related neural activity during observation of daily activities such as lifting with a flexed spine in LBP and pain-free subjects [35,36,57]. However, the underlying psychomotor interactions between pain-related fear and spinal motion are largely unknown and need to be elucidated to disentangle possible clinically relevant relationships between pain-related fear, spinal motion and negative outcomes such as persistent LBP and disability.…”

Fear-avoidance beliefs are associated with reduced lumbar spine flexion during object lifting in pain-free adults

“… 7 , 8 Brain research further supports this by demonstrating distinct relationships between self-reports of pain-related fear and fear-related neural activity during observation of daily activities such as lifting with a flexed spine in LBP and pain-free subjects. 37 , 38 , 62 However, the underlying interactions between pain-related fear and spinal motion are largely unknown and need to be elucidated to disentangle possible clinically relevant relationships between pain-related fear, spinal motion, and negative outcomes such as persistent LBP and disability. With respect to this, there is a lack of studies measuring lumbar spine flexion during lifting mimicking real-life settings, 55 especially with regards to psychological factors in people with and without LBP.…”