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The need for developing a simple and effective assessment tool for muscle mass has been increasing in a rapidly aging society. This study aimed to evaluate the feasibility of the surface electromyography (sEMG) parameters for estimating muscle mass. Overall, 212 healthy volunteers participated in this study. Maximal voluntary contraction (MVC) strength and root mean square (RMS) values of motor unit potentials from surface electrodes on each muscle (biceps brachii, triceps brachii, biceps femoris, rectus femoris) during isometric exercises of elbow flexion (EF), elbow extension (EE), knee flexion (KF), knee extension (KE) were acquired. New variables (MeanRMS, MaxRMS, and RatioRMS) were calculated from RMS values according to each exercise. Bioimpedance analysis (BIA) was performed to determine the segmental lean mass (SLM), segmental fat mass (SFM), and appendicular skeletal muscle mass (ASM). Muscle thicknesses were measured using ultrasonography (US). sEMG parameters showed positive correlations with MVC strength, SLM, ASM, and muscle thickness measured by US, but showed negative correlations with SFM. An equation was developed for ASM: ASM = −26.04 + 20.345 × Height + 0.178 × weight − 2.065 × (1, if female; 0, if male) + 0.327 × RatioRMS(KF) + 0.965 × MeanRMS(EE) (SEE = 1.167, adjusted R2 = 0.934). sEMG parameters in controlled conditions may represent overall muscle strength and muscle mass in healthy individuals. [ABSTRACT FROM AUTHOR]

Background: Standard autonomic testing includes a 10-minute head-up tilt table test to detect orthostatic hypotension. Although this test can detect delayed orthostatic hypotension (dOH) between 3 and 10 minutes of standing, it cannot detect late-onset dOH after 10 minutes of standing. Methods: To determine whether Valsalva maneuver responses can identify patients who would require prolonged head-up tilt table test to diagnose late-onset dOH; patients with immediate orthostatic hypotension (onset <3 minutes; n=176), early-onset dOH (onset between 3 and 10 minutes; n=68), and late-onset dOH (onset >10 minutes; n=32) were retrospectively compared with controls (n=114) with normal head-up tilt table test and composite autonomic scoring scale score of 0. Results: Changes in baseline systolic blood pressure at late phase 2 (∆SBPVM2), heart rate difference between baseline and phase 3 (∆HRVM3), and Valsalva ratio were lower and pressure recovery time (PRT) at phase 4 was longer in late-onset dOH patients than in controls. Differences in PRT and ∆HRVM3 remained significant after correcting for age. A PRT ≥2.14 s and ∆HRVM3 ≤15 bpm distinguished late-onset dOH from age- and sex-matched controls. Patients with longer PRT (relative risk ratio, 2.189 [1.579–3.036]) and lower ∆HRVM3 (relative risk ratio, 0.897 [0.847–0.951]) were more likely to have late-onset dOH. Patients with longer PRT (relative risk ratio, 1.075 [1.012–1.133]) were more likely to have early-onset than late-onset dOH. Conclusions: Long PRT and short ∆HRVM3 can help to identify patients who require prolonged head-up tilt table test to diagnose late-onset dOH. [ABSTRACT FROM AUTHOR]

Introduction: Although white matter hyperintensity (WMH) shares similar vascular risk and pathology with small vessel occlusion (SVO) stroke, there were few studies to evaluate the impact of the burden of WMH volume on early and delayed stroke outcomes in SVO stroke., Materials and Methods: Using a multicenter registry database, we enrolled SVO stroke patients between August 2013 and November 2022. The WMH volume was estimated by automated methods using deep learning (VUNO Med-DeepBrain, Seoul, South Korea), which was a commercially available segmentation model. After propensity score matching (PSM), we evaluated the impact of WMH volume on early neurological deterioration (END) and poor functional outcomes at 3-month modified Ranking Scale (mRS), defined as mRS score >2 at 3 months, after an SVO stroke., Results: Among 1,718 SVO stroke cases, the prevalence of subjects with severe WMH (Fazekas score ≥ 3) was 68.9%. After PSM, END and poor functional outcomes at 3-month mRS (mRS > 2) were higher in the severe WMH group (END: 6.9 vs. 13.5%, p < 0.001; 3-month mRS > 2: 11.4 vs. 24.7%, p < 0.001). The logistic regression analysis using the PSM cohort showed that total WMH volume increased the risk of END [odd ratio [OR], 95% confidence interval [CI]; 1.01, 1.00-1.02, p = 0.048] and 3-month mRS > 2 (OR, 95% CI; 1.02, 1.01-1.03, p < 0.001). Deep WMH was associated with both END and 3-month mRS > 2, but periventricular WMH was associated with 3-month mRS > 2 only., Conclusion: This study used automated methods using a deep learning segmentation model to assess the impact of WMH burden on outcomes in SVO stroke. Our findings emphasize the significance of WMH burden in SVO stroke prognosis, encouraging tailored interventions for better patient care., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Lee, Suh, Sohn, Kim, Han, Sung, Yu, Lim and Lee.)