Efficacy and Safety of Vagus Nerve Stimulation in Stroke Rehabilitation: A Systematic Review and Meta-Analysis.

INTRODUCTION: Recent randomized controlled trials (RCTs) have assessed the role of vagus nerve stimulation (VNS) when paired with standard rehabilitation in stroke patients. This review aimed to evaluate the efficacy and safety of VNS as a novel treatment option for post-stroke recovery. METHODS: We searched PubMed, EMBASE, Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials (CENTRAL), and CINAHL Plus for articles published from their date of inception to June 2021. RCTs investigating the efficacy or safety of VNS on post-stroke recovery were included. The outcomes were upper limb sensorimotor function, health-related quality of life, level of independence, cardiovascular effects, and adverse events. The risk of bias was assessed using the Cochrane risk-of-bias tool, while the certainty of the evidence was assessed using the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) criteria. Review Manager 5.4 was used to conduct the meta-analysis. RESULTS: Seven RCTs (n = 236 subjects) met the eligibility criteria. Upper limb sensorimotor function, assessed by the Fugl-Meyer Assessment for Upper Extremity (FMA-UE), improved at day 1 (n = 4 RCTs; standardized mean difference [SMD] 1.01; 95% confidence interval [CI]: 0.35-1.66) and day 90 post-intervention (n = 3 RCTs; SMD 0.64; 95% CI: 0.31-0.98; moderate certainty of evidence) but not at day 30 follow-up (n = 2 RCTs; SMD 1.54; 95% CI: -0.39 to 3.46). Clinically significant upper limb sensorimotor function recovery, as defined by ≥6 points increase in FMA-UE, was significantly higher at day 1 (n = 2 RCTs; risk ratio [RR] 2.01; 95% CI: 1.02-3.94) and day 90 post-intervention (n = 2 RCTs; RR 2.14; 95% CI: 1.32-3.45; moderate certainty of the evidence). The between-group effect sizes for upper limb sensorimotor function recovery was medium to large (Hedges' g 0.535-2.659). While the level of independence improved with VNS, its impact on health-related quality of life remains unclear as this was only studied in two trials with mixed results. Generally, adverse events reported were mild and self-limiting. CONCLUSION: VNS may be an effective and safe adjunct to standard rehabilitation for post-stroke recovery; however, its clinical significance and long-term efficacy and safety remain unclear.

Evaluation of different teas against starch digestibility by mammalian glycosidases.

Current work investigated the ability of different tea (green, oolong and black teas) in inhibiting human salivary alpha-amylase (HSA) and mammalian alpha-glucosidase (AGH). The inhibitory profiles were correlated to their major polyphenol content (theaflavins and catechins). The fully fermented black tea was demonstrated to be most potent in inhibiting HSA and AGH (IC50 of 0.42 to 0.67 and 0.56 to 0.58 mg of tea leaves/mL respectively). Its capability in retarding the digestion of a real food system (rice noodle) was further elucidated with an in vitro digestion study. Results indicated that black tea was able to retard starch digestion moderately, thereby allowing a gradual reduction of sugar liberation. Polyphenolic profile analysis suggested that the oxidized catechins, theaflavins, may be responsible for its activity. We have found that refractive index (RI) measurement is a rapid, direct, and highly convenient method for quantifying the degree of enzymatic starch digestion and kinetics. The RI method has good linearity range, limit of detection (0.1596 mg/mL, maltose equivalent) and limit of quantitation (0.6312 mg/mL) and was successfully applied in our study.