Recent studies have investigated muscle synergies as biomarkers for stroke, but it remains controversial if muscle synergies and clinical observation convey the same information on motor impairment. We aim to identify whether muscle synergies and clinical scales convey the same information or not. Post-stroke patients were administered an upper limb treatment. Before (T0) and after (T1) treatment, we assessed motor performance with clinical scales and motor output with EMG-derived muscle synergies. We implemented an exploratory factor analysis (EFA) and a confirmatory factor analysis (CFA) to identify the underlying relationships among all variables, at T0 and T1, and a general linear regression model to infer any relationships between the similarity between the affected and unaffected synergies (Median-sp) and clinical outcomes at T0. Clinical variables improved with rehabilitation whereas muscle-synergy parameters did not show any significant change. EFA and CFA showed that clinical variables and muscle-synergy parameters (except Median-sp) were grouped into different factors. Regression model showed that Median-sp could be well predicted by clinical scales. The information underlying clinical scales and muscle synergies are therefore different. However, clinical scales well predicted the similarity between the affected and unaffected synergies. Our results may have implications on personalizing rehabilitation protocols.

Objective: The aim of this systematic review with meta-analysis was to evaluate the effectiveness of RMT in internal and central nervous system disorders, on pulmonary function, exercise capacity and quality of life. Methods: The inclusion criteria were (1) publications designed as Randomized Controlled Trial (RCT), with (2) participants being adults with pulmonary dysfunction caused by an internal disease or central nervous system disorder, (3) an intervention defined as RMT (either IMT or EMT) and (4) with the assessment of exercise capacity, respiratory function and quality of life. For the methodological quality assessment of risk of bias, likewise statistical analysis and meta-analysis the RevMan version 5.3 software and the Cochrane Risk of Bias Tool were used. Two authors independently analysed the following databases for relevant research articles: PubMed, Scopus, Cochrane Library, Web of Science, and Embase. Results: From a total of 2200 records, the systematic review includes 29 RCT with an overall sample size of 1155 patients. Results suggest that patients with internal and central nervous system disorders who underwent RMT had better quality of life and improved significantly their performance in exercise capacity and in respiratory function assessed with FVC and MIP when compared to control conditions (i.e. no intervention, sham training, placebo or conventional treatments). Conclusion: Respiratory muscle training seems to be more effective than control conditions (i.e. no intervention, sham training, placebo or conventional treatment), in patients with pulmonary dysfunction due to internal and central nervous system disorders, for quality of life, exercise capacity and respiratory function assessed with MIP and FVC, but not with FEV1.

To characterize individuals with stroke who responded or did not respond to upper limb motor treatment by analyzing muscle synergy patterns (similarity, merging and fractionation). This study is a secondary analysis of a multicentre randomized controlled trial. Inpatients of two specialised neurorehabilitation hospitals. We enrolled 62 individuals with a unilateral first-event ischemic or haemorrhagic stroke and severe-to-mild upper limb motor impairment (Fugl-Meyer Assessment Upper Extremity score of 5 to 61, out of 66). We excluded people with untreated seizure, severe cognitive or verbal comprehension impairment. After randomization, individuals were allocated to conventional, virtual reality or robot-assisted treatment groups (20 sessions, 1h/day, 5d/week, 4 weeks). A blinded assessor performed assessments both before and after the intervention. Surface electromyography recordings from 16 muscles during reaching tasks were collected pre- and post-treatment. We extracted muscle synergy patterns (similarity, merging, and fractionation) of the stroke-affected and unaffected upper limb of each subject. Overall, individuals improved upper limb motor function (Fugl-Meyer Assessment Upper Extremity change score = 7.14 ± 7.46, p< 0.001). We identified 34 responders to treatment showing clinically significant improvement (over the Minimal Clinically Important Difference of 5 points on the Fugl-Meyer Assessment-Upper Extremity). The responders showed decreased merging of synergies (p=0.016) as compared with the non-responders (p=0.025), who conversely showed improved similarity of synergies (p=0.006). In individuals with stroke undergoing upper limb motor rehabilitation, changes in the synergy merging pattern may serve as a potential marker to distinguish responders from non-responders. The trial is registered in ClinicalTrial.gov, identifier number NCT03530358 (https://clinicaltrials.gov/study/NCT03530358).

A single-blind randomized controlled trial was conducted to compare whether the continuous visualization of a virtual teacher, during virtual reality rehabilitation, is more effective than the same treatment provided without a virtual teacher visualization, for the recovery of arm motor function after stroke. Teacher and no-teacher groups received the same amount of virtual reality therapy (i.e., 1 h/d, 5 dd/w, 4 ww) and an additional hour of conventional therapy. In the teacher group, specific feedback (“virtual-teacher”) showing the correct kinematic to be emulated by the patient was always displayed online during exercises. In the no-teacher group patients performed the same exercises, without the virtual-teacher assistance. The primary outcome measure was Fugl-Meyer Upper Extremity after treatment. 124 patients were enrolled and randomized, 62 per group. No differences were observed between the groups, but the same number of patients (χ² = 0.29, p = 0.59) responded to experimental and control interventions in each group. The results confirm that the manipulation of a single instant feedback does not provide clinical advantages over multimodal feedback for arm rehabilitation after stroke, but combining 40 h conventional therapy and virtual reality provides large effect of intervention (i.e., Cohen’s d 1.14 and 0.92 for the two groups, respectively).

BackgroundHumans often use co-speech gestures to promote effective communication. Attention has been paid to the cortical areas engaged in the processing of co-speech gestures.AimsTo investigate the neural network underpinned in the processing of co-speech gestures and to observe whether there is a relationship between areas involved in language and gesture processing.Methods & ProceduresWe planned to include studies with neurotypical and/or stroke participants who underwent a bimodal task (i.e., processing of co-speech gestures with relative speech) and a unimodal task (i.e., speech or gesture alone) during a functional magnetic resonance imaging (fMRI) session. After a database search, abstract and full-text screening were conducted. Qualitative and quantitative data were extracted, and a meta-analysis was performed with the software GingerALE 3.0.2, performing contrast analyses of uni- and bimodal tasks.Main ContributionThe database search produced 1024 records. After the screening process, 27 studies were included in the review. Data from 15 studies were quantitatively analysed through meta-analysis. Meta-analysis found three clusters with a significant activation of the left middle frontal gyrus and inferior frontal gyrus, and bilateral middle occipital gyrus and inferior temporal gyrus.ConclusionsThere is a close link at the neural level for the semantic processing of auditory and visual information during communication. These findings encourage the integration of the use of co-speech gestures during aphasia treatment as a strategy to foster the possibility to communicate effectively for people with aphasia.