Chronic pain is one of the major causes of disability with a tremendous impact on an individual's quality of life and on public health. Transcutaneous vagus nerve stimulation (tVNS) is a safe therapeutic for this condition. We aimed to evaluate its effects in adults with chronic pain. A comprehensive search was performed, including randomized controlled trials published until October 2023, which assessed the effects of noninvasive tVNS. Cohen's d effect size and 95% confidence intervals (CIs) were calculated, and random-effects meta-analyses were performed. Fifteen studies were included. The results revealed a mean effect size of 0.41 (95% CI 0.17-0.66) in favor of tVNS as compared with control, although a significant heterogeneity was observed (χ² = 21.7, df = 10, P = 0.02, I ² = 53.9%). However, when compared with nonactive controls, tVNS shows a larger effect size (0.79, 95% CI 0.25-1.33), although the number of studies was small (n = 3). When analyzed separately, auricular tVNS and cervical tVNS against control, it shows a significant small to moderate effect size, similar to that of the main analysis, respectively, 0.42 (95% CI 0.08-0.76, 8 studies) and 0.36 (95% CI 0.01-0.70, 3 studies). No differences were observed in the number of migraine days for the trials on migraine. This meta-analysis indicates that tVNS shows promise as an effective intervention for managing pain intensity in chronic pain conditions. We discuss the design of future trials to confirm these preliminary results, including sample size and parameters of stimulation.

Background: Depression and anxiety are non-motor symptoms of Parkinson’s disease (PD). Physical exercise is a promising approach to reducing neuropsychological burden. We aimed to comprehensively synthesize evidence regarding the use of exercise for treating depression and anxiety symptoms in PD. Methods: Systematic review and meta-analysis following PRISMA recommendations. Searches on PubMed, Cochrane Library, Scopus, Web of Science, Embase, and Physiotherapy Evidence Database (PEDro) was conducted. The random-effects model was employed for all analyses with the standardized mean difference as the effect estimate. Results: Fifty records were retrieved, but only 17 studies met the criteria for the meta-analyses. A moderate to large effect was observed for depression (−.71 [95% CI = −.96 to −.46], 11 studies, 728 individuals), and a small to moderate effect for anxiety (−.39 [95% CI = −.65 to −.14], 6 studies, 241 individuals), when comparing exercise to non-exercise controls. Subgroup analysis revealed significant effects from aerobic (−.95 [95% CI = −1.60, −.31]), mind-body (−1.85 [95% CI = −2.63, −1.07]), and resistance modalities (−1.61 [95% CI = −2.40, −.83]) for depression, and from mind-body (−.67 [95% CI = −1.19 to −.15]) and resistance exercises (−1.00 [95% CI = −1.70 to −.30]) for anxiety. Conclusion: Physical exercise has a relevant clinical impact on depression and anxiety in PD. We discuss the level of the evidence, the methodological limitations of the studies, and give recommendations.

Introduction Parkinson’s disease is a movement disorder that also manifests non-motor symptoms (NMS). Physical exercise is a prominent strategy that can have an impact on NMS; however, the evidence is limited. Our aim was to verify the effects of exercise on NMS, as assessed using general NMS scales. Methods This study is a systematic review and meta-analysis. Two searches were conducted on the PubMed, Cochrane Library, Scopus, Web of Science, Embase, Science Direct and PEDro databases from September to December 2022. The PEDro scale was used to assess the methodological quality of the studies. Results Twenty-three studies were included. The interventions were classified as multimodal, aerobic, resistance, dance, conventional physical therapy and other types. Five studies had high risk of bias. Eight studies were included in the meta-analyses. According to the criteria, four studies compared exercise with non-exercise (n=159), two compared multimodal exercise with cognitive/leisure approaches (n=128), and two compared aerobic with conventional exercise (n=40). No statistical differences were observed between exercise and non-exercise (−0.26 (−0.58 to 0.05)) and between multimodal and cognitive approaches (0.21 (−0.14 to 0.55)). However, trends were observed in the direction of exercise and cognitive approaches. A significant difference was observed favouring aerobic over conventional exercise (−0.72 (−1.36 to −0.08)). Conclusions Our findings suggest that exercise may have an effect on general NMS compared with non-exercise, although only a trend was observed. It was also observed for cognitive approaches over multimodal exercises. Aerobic exercise showed near-large effects compared with conventional exercise.

Background: Phantom limb pain (PLP) is highly prevalent after amputation. However, the influence of non-painful sensations (PLS) remains unclear. This study examines the PLP-PLS index as a novel tool to differentiate PLP from PLS and explores the association of clinical factors with the index. Methods: We conducted a cross-sectional analysis of baseline data from 112 participants in a previous factorial trial in patients with unilateral traumatic lower limb amputation. Linear regression models were used to examine the associations between the index and various demographic, psychological and clinical factors. Logistic and Poisson regression, and e-value calculation were utilized for sensitivity analyses. Results: Adjusted multivariable linear regression models demonstrated significant associations of phantom movement sensation (β: −1.532; 95% CI: −2.615 to −0.449; p = 0.006) and time since amputation (β: 0.005; 95% CI: 0.0006 to 0.0101; p = 0.026) with the PLP-PLS index. These findings were confirmed by multivariable logistic regression (phantom movement sensation OR: 0.469; 95% CI: 0.200 to 1.099, p = 0.082; time since amputation OR: 1.003; 95% CI: 1.00003 to 1.007; p = 0.048) and sensitivity analyses. Conclusions: Time since amputation and phantom movement sensation likely reflect distinct phenotypes and potential mechanisms for PLP and PLS. The PLP-PLS index is a promising clinical tool for selecting therapies to prevent/treat PLP and for measuring treatment effects to modulate phantom pain. These findings emphasize the importance of understanding the mechanisms underlying PLP and PLS for improving clinical management and guiding future research.

Background: This study aimed to explore the potential associations between voice metrics of patients with PD and their motor symptoms. Methods: Motor and vocal data including the Unified Parkinson’s Disease Rating Scale part III (UPDRS-III), Harmonic–Noise Ratio (HNR), jitter, shimmer, and smoothed cepstral peak prominence (CPPS) were analyzed through exploratory correlations followed by univariate linear regression analyses. We employed these four voice metrics as independent variables and the total and sub-scores of the UPDRS-III as dependent variables. Results: Thirteen subjects were included, 76% males and 24% females, with a mean age of 62.9 ± 10.1 years, and a median Hoehn and Yahr stage of 2.3 ± 0.7. The regression analysis showed that CPPS is associated with posture (UPDRS-III posture scores: β = −0.196; F = 10.0; p = 0.01; R² = 0.50) and UPDRS-III postural stability scores (β = −0.130; F = 5.57; p = 0.04; R² = 0.35). Additionally, the associations between CPPS and rapid alternating movement (β = −0.297; p = 0.07), rigidity (β= −0.36; p = 0.11), and body bradykinesia (β = −0.16; p = 0.13) showed a trend towards significance. Conclusion: These findings highlight the potential role of CPPS as a predictor of postural impairments secondary to PD, emphasizing the need for further investigation.