Functional electrical stimulation for foot drop in multiple sclerosis: a systematic review and meta-analysis of the effect on gait speed

Objective: To review the efficacy of functional electrical stimulation (FES) used for foot drop in people with multiple sclerosis (pwMS) on gait speed in short and long walking performance tests. Data sources: Five databases (Cochrane Library, CINAHL, Embase, MEDLINE, Pubmed) and reference lists were searched. Study selection: Studies of both observational and experimental design where gait speed data in pwMS could be extracted were included. Data extraction: Data were independently extracted and recorded. Methodological quality was assessed using the Effective Public Health Practice Project (EPHPP) tool. Data synthesis: Nineteen studies (described in 20 articles) recruiting 490 pwMS were identified and rated moderate or weak, with none gaining a strong rating. All studies rated weak for blinding. Initial and ongoing orthotic and therapeutic effects were assessed with regards to the impact of FES on gait speed in short and long walking tests. Meta-analyses of the short walk tests revealed a significant initial orthotic effect (t = 2.14, p = 0.016) with a mean increase in gait speed of 0.05 meters per second (m/s) and ongoing orthotic effect (t = 2.81, p = 0.003) with a mean increase of 0.08m/s. There were no initial or ongoing effect on gait speed in long walk tests and no therapeutic effect on gait speed in either short or long walk tests. Conclusions: FES used for foot drop has a positive initial and ongoing effect on gait speed in short walking tests. Further fully-powered randomized controlled trials comparing FES with alternative treatments are required

Galois theory and commutators

We prove that the relative commutator with respect to a subvariety of a variety of Omega-groups introduced by the first author can be described in terms of categorical Galois theory. This extends the known correspondence between the Froehlich-Lue and the Janelidze-Kelly notions of central extension. As an example outside the context of Omega-groups we study the reflection of the category of loops to the category of groups where we obtain an interpretation of the associator as a relative commutator.Comment: 14 page

Impact of Resistance Therapy on Motor Function in Children with Cerebral Palsy: A Systematic Review and Meta-Analysis

Cerebral palsy is one of the main causes of disability in childhood. Resistance therapy shows benefits in increasing strength and gait in these patients, but its impact on motor function is not yet clear. The objective was to analyze the impact of resistance therapy on the improvement in the motor function using a review and meta-analysis. A comprehensive literature research was conducted in Medline (PubMed), Institute for Scientific Information (ISI) Web of Knowledge, and Physiotherapy Evidence Database (PEDro) in relation to clinical trials in which resistance therapy was used and motor function was assessed. Twelve controlled clinical trials and three non-controlled clinical trials (only one intervention arm) studies were identified. In terms of pre?post difference, the overall intra-group effect was in favor of resistance therapy intervention: standardized mean difference (SMD) = 0.37, 95% confidence interval (CI) = 0.21 to 0.52, p < 0.001 (random-effects model), with moderate heterogeneity (I2 = 59.82%). SMDs were also positive by restricting to each of the analyzed scales: SMD = 0.37, 1.33, 0.10, and 0.36 for Gross Motor Function Measure (GMFM), Lateral Step Up (LSU), Time Up and Go (TUG), and Mobility Questionnaire (MobQue) scales, respectively. Regarding the difference between groups, the results showed a high heterogeneity (I2 < 99%), with the mean difference (MD) also favorable for the GMFM scale: MD = 1.73, 95% CI = 0.81 to 2.64, p < 0.001 (random-effects model). Our results support a positive impact of resistance therapy on motor function. Further studies should delve into the clinical relevance of these results

Brain morphology in children with 47, XYY syndrome: a voxel- and surface-based morphometric study.

The neurocognitive and behavioral profile of individuals with 47,XYY is increasingly documented; however, very little is known about the effect of a supernumerary Y-chromosome on brain development. Establishing the neural phenotype associated with 47,XYY may prove valuable in clarifying the role of Y-chromosome gene dosage effects, a potential factor in several neuropsychiatric disorders that show a prevalence bias toward males, including autism spectrum disorders. Here, we investigated brain structure in 10 young boys with 47,XYY and 10 age-matched healthy controls by combining voxel-based morphometry (VBM) and surface-based morphometry (SBM). The VBM results show the existence of altered gray matter volume (GMV) in the insular and parietal regions of 47,XYY relative to controls, changes that were paralleled by extensive modifications in white matter (WM) bilaterally in the frontal and superior parietal lobes. The SBM analyses corroborated these findings and revealed the presence of abnormal surface area and cortical thinning in regions with abnormal GMV and WMV. Overall, these preliminary results demonstrate a significant impact of a supernumerary Y-chromosome on brain development, provide a neural basis for the motor, speech and behavior regulation difficulties associated with 47,XYY and may relate to sexual dimorphism in these areas

Relative Commutator Theory in Semi-Abelian Categories

Basing ourselves on the concept of double central extension from categorical Galois theory, we study a notion of commutator which is defined relative to a Birkhoff subcategory B of a semi-abelian category A. This commutator characterises Janelidze and Kelly's B-central extensions; when the subcategory B is determined by the abelian objects in A, it coincides with Huq's commutator; and when the category A is a variety of omega-groups, it coincides with the relative commutator introduced by the first author.Comment: 22 page