Do depressive and anxiety symptoms influence the construct validity of Multiple Sclerosis Walking Scale-12 scores?

PURPOSE/OBJECTIVE: Walking dysfunction, depression, and anxiety are prevalent, burdensome, and interrelated outcomes in persons with multiple sclerosis (MS). The 12-item Multiple Sclerosis Walking Scale (MSWS-12) is a common patient-reported outcome (PRO) of walking dysfunction in research and practice involving MS, but the construct validity of its scores might be influenced by symptoms of depression and anxiety. This study examined if symptoms of depression and anxiety influenced the construct validity of MSWS-12 scores. RESEARCH METHOD/DESIGN: The sample included 189 participants with MS who completed the MSWS-12, Hospital Anxiety and Depression Scale (HADS-Depression subscale [HADS-D] and HADS-Anxiety subscale [HADS-A]), 6-minute walk (6MW), and timed 25-foot walk (T25FW). We conducted bivariate correlation analysis to examine the associations between MSWS-12 scores and both the 6MW and T25FW, while controlling for HADS-D and HADS-A scores. RESULTS: MSWS-12 scores were significantly correlated with the 6MW (r = -.752), T25FW (r = .694), HADS-D (r = .405), and HADS-A (r = .235). The correlations between MSWS-12 and 6MW (pr = -.725) and T25FW (pr = .685) did not change when controlling for HADS-D and HADS-A scores. The correlations between MSWS-12 and 6MW (r = -.708 and r = -.726) and T25FW (r = .687 and r = .748) were strong in subsamples with elevated HADS-D and HADS-A scores. CONCLUSIONS/IMPLICATIONS: Our results strengthen the validity evidence for MSWS-12 scores as a PRO of walking dysfunction in MS, including among those with symptoms of depression and anxiety. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Social Cognitive Theory variables as correlates of physical activity in fatigued persons with multiple sclerosis.

BACKGROUND: There is interest in the application of behavioral interventions based on theory for increasing physical activity among adults with multiple sclerosis (MS). To date, researchers have applied theory such as Social Cognitive Theory (SCT) for identifying correlates of physical activity that can then inform the design and delivery of behavioral interventions. Such research often has been conducted in heterogeneous samples of persons with MS without a focus on those with a specific symptom, such as fatigue, that may be targeted by physical activity behavioral interventions. To that end, this study examined SCT variables (i.e., self-efficacy, barriers, outcome expectations, goal-setting, planning, social support, and functional limitations) as correlates of physical activity in persons with MS who self-reported elevated fatigue. METHODS: Persons with MS (N=210; aged 49.6[13.2] years) who ambulated with or without assistance participated in the study. Participants completed self-report measures of fatigue, physical activity, and SCT variables and wore an ActiGraph GT3X+ accelerometer on a belt around the waist for 7 days. The accelerometer data were processed and delineated into time spent in light and moderate-to-vigorous physical activity (MVPA) based on MS-specific cut-points. We generated groups of fatigued (n=134) and non-fatigued (n=76) persons with MS based on the cut-off score of 4 for the Fatigue Severity Scale. RESULTS: There were differences in physical activity and SCT variables between fatigued and non-fatigued persons with MS. Among those with fatigue, functional limitations (ρ=0.52), self-efficacy (ρ=0.31), and goal-setting (ρ=0.25) were associated with device-measured MVPA, and all SCT variables except outcome expectations were associated with self-reported physical activity. The regression analyses indicated self-efficacy, functional limitations, and goal-setting as significant correlates of MVPA in those with fatigue. CONCLUSION: Self-efficacy, goal-setting, and social support may be important targets of SCT-based behavioral interventions for increasing physical activity among persons with MS who have fatigue.

Do physical activity and social cognitive theory variable scores differ across symptom cluster severity groups in multiple sclerosis?

BACKGROUND: Persons with multiple sclerosis (MS) experience co-occurring symptoms termed "symptom clusters" that can be distinguished based on mild, moderate, or severe symptom severity termed "symptom cluster severity." Physical activity (PA) may be an approach for improving co-occurring symptoms. OBJECTIVE: To examined if PA and social cognitive theory (SCT) variables differed by symptom cluster groups, and if associations between SCT variables and PA were moderated by symptom cluster groups. METHODS: Secondary analysis of participants with MS (N = 205) enrolled in a cross-sectional study. Trend analyses were conducted to determine if device-measured and self-reported PA and SCT variables (i.e., social support, self-efficacy, outcome expectations, goal setting, planning, and impediments) decreased with increased symptom cluster severity. Spearman rho rank-order correlations were conducted between PA measures and SCT variables within each symptom cluster group. RESULTS: Linear trend analyses indicated that self-reported PA declined with increased symptom cluster severity groups (F = 4.90,p = 0.03). Linear trend analyses indicated significant differences among symptom cluster severity groups in social support (F = 31.43,p = 0.001), exercise self-efficacy (F = 22.55,p = 0.001), barrier self-efficacy (F = 11.48,p = 0.001), outcome expectations (F = 6.98,p = 0.009), and impediments (F = 34.41,p = 0.001). There were differential associations of moderate magnitude in correlations, such that three SCT variables were associated with PA in the mild group (i.e., self-efficacy, goal setting and planning), two in the moderate group (i.e., social support and goal setting), and four in the severe group (i.e., self-efficacy, outcome expectations, planning, and social support). CONCLUSIONS: Further research is warranted examining the use of SCT-based behavior change techniques for promoting PA and improving symptom clusters in persons with MS.

Symptom clusters and quality of life in persons with multiple sclerosis across the lifespan.

PURPOSE: To describe symptom clusters based on severity of co-occurring symptoms among adults with multiple sclerosis (MS) by age groups and to further examine symptom clusters as a correlate of quality of life (QOL) by age groups. METHODS: This cross-sectional study enrolled persons with MS between 20 and 79 years of age who completed measures of fatigue, depression, anxiety, sleep quality, and QOL using the 36-Item Short Form Health Survey. Bivariate correlation and partial correlation analyses examined associations among symptoms, QOL, and MS characteristics. K-means cluster analyses determined symptom clusters among the full sample and pre-determined age groups (i.e., 20-39, 40-59, and 60-79). One-way ANOVAs examined differences in QOL among clusters for the overall sample and by age groups. RESULTS: Among the overall sample of 205 participants, symptoms were significantly correlated with QOL and three distinct clusters were identified and differentiated by the magnitude of symptom experience (i.e., mild, moderate, and severe). Results were consistent among young and middle-aged adults; however, among older adults two severe sleep problem clusters were identified that were distinguished by moderate versus severe fatigue, depression, and anxiety. ANOVAs among the overall sample indicated that the three symptom clusters varied significantly for both physical component scores, F(2, 202) = 12.03, p < .001, η2 = .10, and mental component scores, F(2, 202) = 137.92, p < .001, η2 = .58; severe symptom cluster was associated with worse QOL. Patterns in the age subgroup ANOVAs were consistent. CONCLUSIONS: Given the strong association between severity of symptom clusters and QOL, approaches for targeting co-occurring symptoms are critically needed.

The Effect of Low-Carbohydrate and Low-Fat Diets on Pain in Individuals with Knee Osteoarthritis.

OBJECTIVE: Osteoarthritis is the most prominent form of arthritis, affecting approximately 15% of the population in the United States. Knee osteoarthritis (KOA) has become one of the leading causes of disability in older adults. Besides knee replacement, there are no curative treatments for KOA, so persistent pain is commonly treated with opioids, acetaminophen, and nonsteroidal anti-inflammatory drugs. However, these drugs have many unpleasant side effects, so there is a need for alternative forms of pain management. We sought to test the efficacy of a dietary intervention to reduce KOA. DESIGN: A randomized controlled pilot study to test the efficacy of two dietary interventions. SUBJECTS: Adults 65-75 years of age with KOA. METHODS: Participants were asked to follow one of two dietary interventions (low-carbohydrate [LCD], low-fat [LFD]) or continue to eat as usual (control [CTRL]) over 12 weeks. Functional pain, self-reported pain, quality of life, and depression were assessed every three weeks. Serum from before and after the diet intervention was analyzed for oxidative stress. RESULTS: Over a period of 12 weeks, the LCD reduced pain intensity and unpleasantness in some functional pain tasks, as well as self-reported pain, compared with the LFD and CTRL. The LCD also significantly reduced oxidative stress and the adipokine leptin compared with the LFD and CTRL. Reduction in oxidative stress was related to reduced functional pain. CONCLUSIONS: We present evidence suggesting that oxidative stress may be related to functional pain, and lowering it through our LCD intervention could provide relief from pain and be an opioid alternative.

Quantifying blood-spinal cord barrier permeability after peripheral nerve injury in the living mouse.

BACKGROUND: Genetic polymorphisms, gender and age all influence the risk of developing chronic neuropathic pain following peripheral nerve injury (PNI). It is known that there are significant inter-strain differences in pain hypersensitivity in strains of mice after PNI. In response to PNI, one of the earliest events is thought to be the disruption of the blood-spinal cord barrier (BSCB). The study of BSCB integrity after PNI may lead to a better understanding of the mechanisms that contribute to chronic pain. RESULTS: Here we used in vivo dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) to establish a timecourse for BSCB permeability following PNI, produced by performing a spared nerve injury (SNI). From this longitudinal study, we found that the SNI group had a significant increase in BSCB permeability over time throughout the entire spinal cord. The BSCB opening had a delayed onset and the increase in permeability was transient, returning to control levels just over one day after the surgery. We also examined inter-strain differences in BSCB permeability using five mouse strains (B10, C57BL/6J, CD-1, A/J and BALB/c) that spanned the range of pain hypersensitivity. We found a significant increase in BSCB permeability in the SNI group that was dependent on strain but that did not correlate with the reported strain differences in PNI-induced tactile hypersensitivity. These results were consistent with a previous experiment using Evans Blue dye to independently assess the status of the BSCB permeability. CONCLUSIONS: DCE-MRI provides a sensitive and non-invasive method to follow BSCB permeability in the same group of mice over time. Examining differences between mouse strains, we demonstrated that there is an important genetically-based control of the PNI-induced increase in BSCB permeability and that the critical genetic determinants of BSCB opening after PNI are distinct from those that determine genetic variability in PNI-induced pain hypersensitivity.