Factors influencing clinical trial participation of women with fibromyalgia across the United States: a cross-sectional survey.

Although fibromyalgia is a widespread chronic pain condition where 90 percent of patients are women, they are underrepresented in Randomized Clinical Trials (RCTs). We aim to describe the willingness to participate, assess different factors, and explore the impact of sociodemographic and clinical characteristics on perceived barriers to trial participation. This is a cross-sectional survey targeting women with fibromyalgia. Univariate and multivariate logistic regression were performed. Of the 436 women with fibromyalgia, 56 percent were very likely to participate in RCTs. Minorities expressed less interest than non-minorities, while higher pain scores, previous participation, and younger patients reported a higher interest. Barriers significantly associated with a reduced willingness were: the participant's perception (side effects, distance, potential negative impact), the center (reputation), the trial protocol (number of visits, placebo), and trial awareness by their physician. In a multivariate analysis, older age, low education, lower income, and higher pain scores were associated with perceived barriers to RCT participation. Despite the high interest to participate, factors such as side effects, the center's distance, number of visits, placebo treatments, and the institution's reputation must be considered in clinical trials for women with fibromyalgia.

Resting-state EEG as Biomarker of Maladaptive Motor Function and Depressive Profile in Stroke Patients.

Objective: Investigate the relationship between resting-state EEG-measured brain oscillations and clinical and demographic measures in Stroke patients. Methods: We performed a cross-sectional analysis of a cohort study (DEFINE cohort), Stroke arm, with 85 patients, considering demographic, clinical, and stroke characteristics. Resting-state EEG relative power from delta, theta, alpha, and beta oscillations were measured from the central region. Multivariate regression models were used for both affected and non-affected hemispheres. Results: Motor function was negatively associated with Delta and Theta oscillations, while positively associated with Alpha oscillations (both hemispheres). Similarly, cognition levels measured were negatively associated with Delta activity. Depression levels were negatively associated with Alpha activity specifically in the affected hemisphere, while positively associated with Beta activity in both hemispheres. Regarding pain measures, no significant association was observed, while CPM measure showed a positive association with Alpha activity in the non-affected hemisphere. Finally, we found that theta/alpha ratio was negatively associated with motor function and CPM scores. Conclusion: The results lead us to propose a framework for brain oscillations in stroke, whereas Delta and Beta would represent disrupted mal-adaptive brain plasticity and Theta and Alpha would represent compensatory and functional brain oscillations for motor and sensory deficits in stroke, respectively.

Structural and functional motor cortex asymmetry in unilateral lower limb amputation with phantom limb pain.

OBJECTIVE: The role of motor cortex reorganization in the development and maintenance of phantom limb pain (PLP) is still unclear. This study aims to evaluate neurophysiological and structural motor cortex asymmetry in patients with PLP and its relationship with pain intensity. METHODS: Cross-sectional analysis of an ongoing randomized-controlled trial. We evaluated the motor cortex asymmetry through two techniques: i) changes in cortical excitability indexed by transcranial magnetic stimulation (motor evoked potential, paired-pulse paradigms and cortical mapping), and ii) voxel-wise grey matter asymmetry analysis by brain magnetic resonance imaging. RESULTS: We included 62 unilateral traumatic lower limb amputees with a mean PLP of 5.9 (SD = 1.79). We found, in the affected hemisphere, an anterior shift of the hand area center of gravity (23 mm, 95% CI 6 to 38, p = 0.005) and a disorganized and widespread representation. Regarding voxel-wise grey matter asymmetry analysis, data from 21 participants show a loss of grey matter volume in the motor area of the affected hemisphere. This asymmetry seems negatively associated with time since amputation. For TMS data, only the ICF ratio is negatively correlated with PLP intensity (r = -0.25, p = 0.04). CONCLUSION: There is an asymmetrical reorganization of the motor cortex in patients with PLP, characterized by a disorganized, widespread, and shifted hand cortical representation and a loss in grey matter volume in the affected hemisphere. This reorganization seems to reduce across time since amputation. However, it is not associated with pain intensity. SIGNIFICANCE: These findings are significant to understand the role of the motor cortex reorganization in patients with PLP, showing that the pain intensity may be related with other neurophysiological factors, not just cortical reorganization.

Cortical plasticity in phantom limb pain: A fMRI study on the neural correlates of behavioral clinical manifestations.

The neural mechanism of phantom limb pain (PLP) is related to the intense brain reorganization process implicating plasticity after deafferentation mostly in sensorimotor system. There is a limited understanding of the association between the sensorimotor system and PLP. We used a novel task-based functional magnetic resonance imaging (fMRI) approach to (1) assess neural activation within a-priori selected regions-of-interested (motor cortex [M1], somatosensory cortex [S1], and visual cortex [V1]), (2) quantify the cortical representation shift in the affected M1, and (3) correlate these changes with baseline clinical characteristics. In a sample of 18 participants, we found a significantly increased activity in M1 and S1 as well as a shift in motor cortex representation that was not related to PLP intensity. In an exploratory analyses (not corrected for multiple comparisons), they were directly correlated with time since amputation; and there was an association between increased activity in M1 with a lack of itching sensation and V1 activation was negatively correlated with PLP. Longer periods of amputation lead to compensatory changes in sensory-motor areas; and itching seems to be a protective marker for less signal changes. We confirmed that PLP intensity is not associated with signal changes in M1 and S1 but in V1.