BACKGROUND:Neuropathic Pain (NP) is a chronic pain caused by damage to the nervous system, often manifested as spontaneous pain, pain allergy and abnormal pain. Cold abnormal pain is one of the common manifestations of neuropathic pain, which seriously affects the quality of life of patients. Lumbar sympathetic nerve resection has been widely used to treat lower limb pain, but its specific mechanism in cold abnormal pain is not yet clear. MATERIALS:A chronic constriction injury (CCI) of the sciatic nerve model and a lumbar sympathectomy (LS) model were established to investigate the effect of LS on abnormal cold pain in CCI rats and its molecular mechanism. The effect of LS on cold allodynia in CCI rats was observed through behavioral tests, including the measurement of mechanical pain threshold, the acetone cold stimulation test, and the cold plate test. The changes in the levels of differentially expressed genes in CCI rats after LS were further observed by transcriptome sequencing (bulk RNA-seq). RESULT:Through behavioural experiments and transcriptome sequencing (bulk RNA-Seq) analysis, we found that lumbar sympathectomy (LS) significantly alleviated cold allodynia, cold-evoked allodynia and cold pain sensitivity in CCI rats, and changed the spinal cord transcriptome, including pathways related to inflammatory signal transduction and tissue remodelling. The functional enrichment analysis of differential expression genes (DEGs) revealed a number of signalling pathways associated with pain regulation. This study provides a new molecular biological basis for the application of LS in alleviating cold abnormal pain.
OBJECTIVE:To evaluate physical activity and balance in children with OBPP (Obstetric Brachial Plexus Palsy) and investigate the relationship between these variables. PARTICIPANTS AND SETTING:The study included 58 children with OBPP and 58 healthy controls aged 7-12 years. METHODS:Physical activity was measured using the Physical Activity Questionnaire for Children (PAQ-C). Dynamic balance was evaluated with the Y Balance Test (YBT), and static balance was assessed using the One-Leg Standing (OLS) test. Outcome measures included scores from these assessments and group comparisons. RESULTS:Children with OBPP showed significant deficits in dynamic balance, particularly in the posterolateral direction (p < 0.05), while static balance and physical activity levels did not differ significantly between groups (p > 0.05). Logistic regression identified the left posterolateral balance score as a significant positive predictor for group classification (p < 0.001). CONCLUSION:Children with OBPP experience significant impairments in dynamic balance, emphasizing the need for targeted interventions to address postural control and lateral stability. Comprehensive assessments incorporating physical activity and balance measures are crucial for developing effective rehabilitation strategies.
Aim of the study: To characterize differences in somatosensory gating associated with maturation, we compared the amplitude ratio of responses to the second stimulus (S2) over the first stimulus (S1) between adolescents and young adults using a paired-pulse stimulation paradigm while recording somatosensory-evoked potentials (SEPs). Methods: Thirteen right-handed adolescent males (14.1 ± 0.3 yrs) and twenty-four adult males (21.2 ± 1.2 yrs) participated. We focused on SEP components at Fz and C3', and sensory gating for each component was quantified as the S2/S1 amplitude. Components showing significant gating were identified within each group. Subsequently, S2/S1 amplitude ratios between groups and bivariate correlations among gated components were examined. Results: Adolescents showed significant gating for N30 at Fz and P22 and P45 at C3', and adults showed significant gating for N30 at Fz and P22 and N60 at C3'. The S2/S1 amplitude ratios for N30 at Fz and P45 at C3' were significantly smaller in adolescents than adults, whereas other components did not differ. Correlations among S2/S1 amplitude ratios were not significant in either group, suggesting component-specific mechanisms. Conclusions: Adolescents showed stronger frontal N30 gating and a different centroparietal pattern relative to adults, suggesting immature and region-specific inhibitory processes. The absence of correlations among S2/S1 ratios supports the presence of partially independent generator and neurochemical mechanisms across SEP components. These findings provide a developmental profile of somatosensory gating.
OBJECTIVE:Light touch sensitivity of the foot sole is typically measured when individuals are seated or lying down; yet, a critical function of the foot sole is to support cutaneous feedback during standing and walking activities. The objective of this study was to evaluate how individuals perceive light touch stimulation across the foot sole while in different postures including standing. METHODS:We measured light touch perceptual threshold (LTPT) in standing, seated, and supine postures in 19 volunteers (10 females, 9 males), using Semmes-Weinstein Monofilaments. Perceptual thresholds were calculated at three foot sole locations (1st metatarsal, lateral arch, and heel) in each posture. RESULTS:Perceptual thresholds were significantly higher in the standing condition compared to the seated and supine conditions across all foot locations; perceptual thresholds were significantly higher while seated compared to supine only at the heel and not at the lateral arch or 1st metatarsal. Our results demonstrate that postural changes significantly influence sensitivity across the foot sole. CONCLUSION:Performing perceptual threshold assessments of the foot sole while standing may offer more relevant insights into the capacity of foot sole cutaneous afferents to convey light touch information in conditions where such feedback plays a vital role in maintaining balance.
