Functional Hyperconnectivity and Task-Based Activity Changes Associated With Neuropathic Pain After Spinal Cord Injury: A Pilot Study

Preliminary evaluation of novel Bodily Attention Task to assess the role of the brain in chemotherapy-induced peripheral neurotoxicity (CIPN)

Chemotherapy-induced peripheral neurotoxicity (CIPN) is a common, sometimes dose-limiting side effect of neurotoxic chemotherapy. Treatment is limited because its pathophysiology is poorly understood. Compared to research on peripheral mechanisms, the role of the brain in CIPN is understudied and it may be important to develop better treatments. We propose a novel task that assesses brain activation associated with attention to bodily sensations (interoception), without the use of painful stimulation, to understand how CIPN symptoms may be processed in the brain. The goals of this preliminary study were to assess, 1) feasibility of the task, 2) sensitivity to changes in brain activity, and 3) suitability for assessing relationships between brain activation and CIPN severity. Eleven participants with varying types of cancer completed a brain fMRI scan and rated CIPN severity (CIPN-20) before and/or 12 weeks after starting neurotoxic chemotherapy. The Bodily Attention Task is a 7.5-min long fMRI task involving attentional focus on the left fingertips, the heart, or a flashing word "target" for visual attention (reference condition). Feasibility was confirmed, as 73% of all data collected were usable and participants reported feeling or focus during 75% of the trials. Regarding brain activity, finger attention increased activation in somatosensory regions (primary sensory cortex, insula) and sensory integration regions (precuneus, dorsolateral prefrontal cortex). Exploratory analyses suggested that brain activation may be associated with CIPN severity. A larger sample size and accounting of confounding factors is needed to test for replication and to identify brain and interoceptive biomarkers to help improve the prediction, prevention, and treatment of CIPN.

A shift of brain network hub after spinal cord injury

Background

Spinal cord injury (SCI) causes severe sequelae and significant social loss, depending on the extent of the damage. Most previous studies have focused on the pathology of the spinal cord to develop treatments for SCI. However, it is now known that the brain, which is not directly damaged, also undergoes morphological changes after spinal cord injury, which could affect natural recovery and treatment. In recent years, magnetic resonance imaging (MRI) has been developed to analyze functional changes in the brain. Resting-state functional MRI (rsfMRI), which captures brain activity at rest, can calculate functional connections between brain areas and identify central hubs by network analysis.

Purpose

We aim to investigate functional connectivity in the brain using rsfMRI after SCI and to determine how brain-network main hubs change over time.

Methods

We evaluated rsfMRI in 10 mice of the contusional SCI model and calculated connectivity using graph theory. We evaluated "centrality," a representative parameter of network analysis. The subtype of centrality was degree centrality, which indicates the hub function of a single area. The five times of rsfMRI were performed in each individual mouse: before injury and at 1, 3, 7, and 14 weeks post-injury.

Results

Before the injury, the degree centralities of the primary and secondary motor cortex were high, suggesting that these motor cortices served as main hubs for motor function. After SCI, the hub function of the motor cortices decreased by 14 weeks. In contrast, hub function in the external capsule and the putamen comparatively increased with time after injury, suggesting that the extrapyramidal/subcortical system, which runs the ventral side of the spinal cord and remains after injury in this model, becomes dominant.

Conclusion

We demonstrated the shift of the brain network hub after SCI. The results of this study provide basic information for understanding brain network changes after SCI and would be useful for treatment selection and evaluation of its efficacy in SCI patients.

Feasibility of using remotely delivered Spring Forest Qigong to reduce neuropathic pain in adults with spinal cord injury: a pilot study

Introduction: Approximately 69% of 299,000 Americans with spinal cord injury (SCI) suffer debilitating chronic neuropathic pain, which is intractable to treatment. The aim of this study is to determine feasibility, as the primary objective, and estimates of efficacy of a remotely delivered Qigong intervention in adults with SCI-related neuropathic pain, as the secondary objective. Methods: We recruited adults with SCI-related neuropathic pain, with SCI ≥3 months, with complete or incomplete SCI, and highest neuropathic pain level of >3 on the Numeric Pain Rating Scale (NPRS), using nationwide volunteer sampling. Using a non-randomized controlled trial design, participants practiced Spring Forest Qigong's "Five Element Qigong Healing Movements" (online video) by combining movement to the best of their ability with kinesthetic imagery, at least 3x/week for 12 weeks. Adherence was automatically tracked through the Spring Forest Qigong website. Outcomes of neuropathic pain intensity (NPRS) were assessed weekly, and SCI-related symptoms were assessed at baseline, 6, and 12 weeks of Qigong practice and at 6-week and 1-year follow-ups. Results: We recruited 23 adults with chronic SCI (7/2021-2/2023). In total, 18 participants started the study and completed all study components, including the 6-week follow-up. Twelve participants completed the 1-year follow-up assessment. Feasibility was demonstrated through participants' willingness to participate, adherence, and acceptability of the study. Mean age of the 18 participants was 60 ± 12 years, and they were 15 ± 11 years post-SCI with the highest baseline neuropathic pain of 7.94 ± 2.33, which was reduced to 4.17 ± 3.07 after 12 weeks of Qigong practice (Cohen's d = 1.75). This pain relief remained at 6-week and 1-year follow-ups. Participants reported reduced spasm frequency (change score 1.17 ± 1.20, d = 0.98) and severity (0.72 ± 1.02, d = 0.71), reduced interference of neuropathic pain on mood (3.44 ± 2.53, d = 1.36), sleep (3.39 ± 2.40, d = 1.41), daily activities (3.17 ± 2.77, d = 1.14), greater ability to perform functional activities (6.68 ± 3.07, d = 2.18), and improved mood (2.33 ± 3.31, d = 0.70) after Qigong. Discussion: Remote Spring Forest Qigong's "Five Element Qigong Healing Movements" practice is feasible in adults with SCI-related neuropathic pain, with promising prolonged results of neuropathic pain relief and improvement in SCI-related symptoms after Qigong practice. Clinical trial registration: https://www.clinicaltrials.gov/ct2/show/NCT04917107, identifier NCT04917107.

Resting state functional connectivity differentiation of neuropathic and nociceptive pain in individuals with chronic spinal cord injury

Many individuals with spinal cord injury live with debilitating chronic pain that may be neuropathic, nociceptive, or a combination of both in nature. Identification of brain regions demonstrating altered connectivity associated with the type and severity of pain experience may elucidate underlying mechanisms, as well as treatment targets. Resting state and sensorimotor task-based magnetic resonance imaging data were collected in 37 individuals with chronic spinal cord injury. Seed-based correlations were utilized to identify resting state functional connectivity of regions with established roles in pain processing: the primary motor and somatosensory cortices, cingulate, insula, hippocampus, parahippocampal gyri, thalamus, amygdala, caudate, putamen, and periaqueductal gray matter. Resting state functional connectivity alterations and task-based activation associated with individuals' pain type and intensity ratings on the International Spinal Cord Injury Basic Pain Dataset (0-10 scale) were evaluated. We found that intralimbic and limbostriatal resting state connectivity alterations are uniquely associated with neuropathic pain severity, whereas thalamocortical and thalamolimbic connectivity alterations are associated specifically with nociceptive pain severity. The joint effect and contrast of both pain types were associated with altered limbocortical connectivity. No significant differences in task-based activation were identified. These findings suggest that the experience of pain in individuals with spinal cord injury may be associated with unique alterations in resting state functional connectivity dependent upon pain type.

Using remotely delivered Spring Forest Qigong™ to reduce neuropathic pain in adults with spinal cord injury: A non-randomized controlled trial

Importance

The manuscript proposes the feasibility and potential of a remote Qigong intervention to reduce neuropathic pain in adults with spinal cord injury (SCI)-related neuropathic pain.

Objective

We determined the feasibility and estimates of efficacy of a remotely delivered Qigong intervention in adults with SCI-related neuropathic pain.

Design

This is a non-randomized controlled trial with outcomes assessed at baseline-, 6- and 12-weeks of Qigong practice, and at 6-weeks and 1-year follow-up.

Setting

Completely remote clinical trial.

Participants

Adults with SCI-related neuropathic pain, with SCI ≥3 months, with complete or incomplete SCI, and highest neuropathic pain level of >3 on the Numeric Pain Rating Scale (NPRS). We used nationwide volunteer sampling.We recruited 23 adults with chronic SCI (7/2021-2/2022). Eighteen participants started the study and completed all study components, including the 6-week follow-up. Twelve participants completed the 1-year follow-up assessment.

Intervention

Participants practiced the Spring Forest Qigong™ "Five Element Healing Movements" with an online video by combining movement with kinesthetic imagery, at least 3x/week for 12 weeks.

Main Outcomes and Measures

To address the feasibility outcome and track adherence, the website automatically monitored the days and duration that the Qigong video was played. Self-report neuropathic pain intensity and SCI-related symptoms such as spasms, functional performance, mood, and body appreciation were also collected.

Results

Eighteen participants, 60±12 years of age, 15±11 years post-SCI had a highest baseline neuropathic pain of 7.94±2.33 on the NPRS, which was reduced to 4.17±3.07 after 12 weeks of Qigong practice (Cohen's d =1.75). This pain relief remained at 6-week and 1-year follow-ups. Participants reported reduced spasm frequency (change score 1.17±1.20, d =0.98) and severity (0.72±1.02, d =0.71), and reduced interference of neuropathic pain on mood (3.44±2.53, d =1.36), sleep (3.39±2.40, d =1.41), and daily activities (3.17±2.77, d =1.14). They had a greater ability to perform functional activities (Patient Specific Functional Scale, 6.68±3.07, d =2.18) and had improved mood (Patient Health Questionnaire-9, 2.33±3.31, d =0.70).

Conclusions and Relevance

Our preliminary data demonstrate the feasibility of Qigong practice in adults with SCI-related neuropathic pain and promising results of neuropathic pain relief and improvement in SCI-related symptoms after Qigong practice.

Trial Registration this manuscript refers to the quasi-experimental substudy

CREATION: A Clinical Trial of Qigong for Neuropathic Pain Relief in Adults with Spinal Cord Injury, NCT04917107 , https://www.clinicaltrials.gov/ct2/show/NCT04917107 .

Identifying Body Awareness-Related Brain Network Changes after Cognitive Multisensory Rehabilitation for Neuropathic Pain Relief in Adults with Spinal Cord Injury: Delayed Treatment arm Phase I Randomized Controlled Trial

Background

Neuropathic pain after spinal cord injury (SCI) is notoriously hard to treat. Mechanisms of neuropathic pain are unclear, which makes finding effective treatments challenging. Prior studies have shown that adults with SCI have body awareness deficits. Recent imaging studies, including ours, point to the parietal operculum and insula as key areas for both pain perception and body awareness. Cognitive multisensory rehabilitation (CMR) is a physical therapy approach that helps improve body awareness for pain reduction and sensorimotor recovery. Based on our prior brain imaging work in CMR in stroke, we hypothesized that improving body awareness through restoring parietal operculum network connectivity leads to neuropathic pain relief and improved sensorimotor and daily life function in adults with SCI. Thus, the objectives of this study were to (1) determine baseline differences in resting-state and task-based functional magnetic resonance imaging (fMRI) brain function in adults with SCI compared to healthy controls and (2) identify changes in brain function and behavioral pain and pain-associated outcomes in adults with SCI after CMR.

Methods

Healthy adults underwent a one-time MRI scan and completed questionnaires. We recruited community-dwelling adults with SCI-related neuropathic pain, with complete or incomplete SCI >3 months, and highest neuropathic pain intensity level of >3 on the Numeric Pain Rating Scale (NPRS). Participants with SCI were randomized into two groups, according to a delayed treatment arm phase I randomized controlled trial (RCT): Group A immediately received CMR intervention, 3x/week, 45 min/session, followed by a 6-week and 1-year follow-up. Group B started with a 6-week observation period, then 6 weeks of CMR, and a 1-year follow-up. Highest, average, and lowest neuropathic pain intensity levels were assessed weekly with the NPRS as primary outcome. Other primary outcomes (fMRI resting-state and functional tasks; sensory and motor function with the INSCI AIS exam), as well as secondary outcomes (mood, function, spasms, and other SCI secondary conditions), were assessed at baseline, after the first and second 6-week period. The INSCI AIS exam and questionnaires were repeated at the 1-year follow-up.

Findings

Thirty-six healthy adults and 28 adults with SCI were recruited between September 2020 and August 2021, and of those, 31 healthy adults and 26 adults with SCI were enrolled in the study. All 26 participants with SCI completed the intervention and pre-post assessments. There were no study-related adverse events. Participants were 52±15 years of age, and 1-56 years post-SCI. During the observation period, group B did not show any reductions in neuropathic pain and did not have any changes in sensation or motor function (INSCI ASIA exam). However, both groups experienced a significant reduction in neuropathic pain after the 6-week CMR intervention. Their highest level of neuropathic pain of 7.81±1.33 on the NPRS at baseline was reduced to 2.88±2.92 after 6 weeks of CMR. Their change scores were 4.92±2.92 (large effect size Cohen's d =1.68) for highest neuropathic pain, 4.12±2.23 ( d =1.85) for average neuropathic pain, and 2.31±2.07 ( d =1.00) for lowest neuropathic pain. Nine participants out of 26 were pain-free after the intervention (34.62%). The results of the INSCI AIS testing also showed significant improvements in sensation, muscle strength, and function after 6 weeks of CMR. Their INSCI AIS exam increased by 8.81±5.37 points ( d =1.64) for touch sensation, 7.50±4.89 points ( d =1.53) for pin prick sensation, and 3.87±2.81 ( d =1.38) for lower limb muscle strength. Functional improvements after the intervention included improvements in balance for 17 out of 18 participants with balance problems at baseline; improved transfers for all of them and a returned ability to stand upright with minimal assistance in 12 out of 20 participants who were unable to stand at baseline. Those improvements were maintained at the 1-year follow-up. With regard to brain imaging, we confirmed that the resting-state parietal operculum and insula networks had weaker connections in adults with SCI-related neuropathic pain (n=20) compared to healthy adults (n=28). After CMR, stronger resting-state parietal operculum network connectivity was found in adults with SCI. Also, at baseline, as expected, right toe sensory stimulation elicited less brain activation in adults with SCI (n=22) compared to healthy adults (n=26). However, after CMR, there was increased brain activation in relevant sensorimotor and parietal areas related to pain and mental body representations (i.e., body awareness and visuospatial body maps) during the toe stimulation fMRI task. These brain function improvements aligned with the AIS results of improved touch sensation, including in the feet.

Interpretation

Adults with chronic SCI had significant neuropathic pain relief and functional improvements, attributed to the recovery of sensation and movement after CMR. The results indicate the preliminary efficacy of CMR for restoring function in adults with chronic SCI. CMR is easily implementable in current physical therapy practice. These encouraging impressive results pave the way for larger randomized clinical trials aimed at testing the efficacy of CMR to alleviate neuropathic pain in adults with SCI.

Clinical Trial registration

ClinicalTrials.gov Identifier: NCT04706208.

Funding

AIRP2-IND-30: Academic Investment Research Program (AIRP) University of Minnesota School of Medicine. National Center for Advancing Translational Sciences of the National Institutes of Health Award Number UL1TR002494; the Biotechnology Research Center: P41EB015894, the National Institute of Neurological Disorders & Stroke Institutional Center Core Grants to Support Neuroscience Research: P30 NS076408; and theHigh-Performancee Connectome Upgrade for Human 3T MR Scanner: 1S10OD017974.

Identifying Body Awareness-Related Brain Network Changes After Cognitive Multisensory Rehabilitation for Neuropathic Pain Relief in Adults With Spinal Cord Injury: Protocol of a Phase I Randomized Controlled Trial

Background

About 69% of the 299,000 Americans living with spinal cord injury (SCI) experience long-term debilitating neuropathic pain. New treatments are needed because current treatments do not provide enough pain relief. We have found that insular-opercular brain network alterations may contribute to neuropathic pain and that restoring this network could reduce neuropathic pain. Here, we outline a study protocol using a physical therapy approach, cognitive multisensory rehabilitation (CMR), which has been shown to restore OP1/OP4 connections in adults post stroke, to test our hypothesis that CMR can normalize pain perception through restoring OP1/OP4 connectivity in adults with SCI and relieve neuropathic pain.

Objectives

To compare baseline brain function via resting-state and task-based functional magnetic resonance imaging in adults with SCI versus uninjured controls, and to identify changes in brain function and behavioral pain outcomes after CMR in adults with SCI.

Methods

In this phase I randomized controlled trial, adults with SCI will be randomized into two groups: Group A will receive 6 weeks of CMR followed by 6 weeks of standard of care (no therapy) at home. Group B will start with 6 weeks of standard of care (no therapy) at home and then receive 6 weeks of CMR. Neuroimaging and behavioral measures are collected at baseline, after the first 6 weeks (A: post therapy, B: post waitlist), and after the second 6 weeks (A: post-therapy follow-up, B: post therapy), with follow-up of both groups up to 12 months.

Conclusion

The successful outcome of our study will be a critical next step toward implementing CMR in clinical care to improve health in adults with SCI.

Effective Connectivity in Spinal Cord Injury-Induced Neuropathic Pain

AIM

The aim of this study was to differentiate the effects of spinal cord injury (SCI) and central neuropathic pain (CNP) on effective connectivity during motor imagery of legs, where CNP is typically experienced.

METHODS

Multichannel EEG was recorded during motor imagery of the legs in 3 groups of people: able-bodied (N = 10), SCI with existing CNP (N = 10), and SCI with no CNP (N = 20). The last group was followed up for 6 months to check for the onset of CNP. Source reconstruction was performed to obtain cortical activity in 17 areas spanning sensorimotor regions and pain matrix. Effective connectivity was calculated using the directed transfer function in 4 frequency bands and compared between groups.

RESULTS

A total of 50% of the SCI group with no CNP developed CNP later. Statistically significant differences in effective connectivity were found between all groups. The differences between groups were not dependent on the frequency band. Outflows from the supplementary motor area were greater for the able-bodied group while the outflows from the secondary somatosensory cortex were greater for the SCI groups. The group with existing CNP showed the least differences from the able-bodied group, appearing to reverse the effects of SCI. The connectivities involving the pain matrix were different between able-bodied and SCI groups irrespective of CNP status, indicating their involvement in motor networks generally.

SIGNIFICANCE

The study findings might help guide therapeutic interventions targeted at the brain for CNP alleviation as well as motor recovery post SCI.