Balance and coordination training and endurance training after nerve injury

Introduction: Different rehabilitation treatments have proven useful in accelerating regeneration. Methods: After sciatic nerve crush in rats, we tested balance and coordination training (BCT) and endurance training (ET) through sensorimotor tests and analyzed nerve and muscle morphology. Results: After BCT and ET, rats performed better in sensorimotor tests than did non‐trained animals. However, only BCT maintained sensorimotor function during training. Furthermore, BCT and ET produced significantly larger muscle area than in non‐trained animals. Conclusions: These findings indicate that BCT and ET, when initiated in the early phase after sciatic nerve injury, improve morphological properties of the soleus muscle and sciatic nerve, but only the task‐oriented BCT maintained sensorimotor function. The success of rehabilitative strategies appears to be highly task‐specific, and strategies that stimulate sensory pathways are the most effective in improving balance and/or coordination parameters. Muscle Nerve 51 : 83–91, 2015     

Reliability of the log‐transformed EMG amplitude‐power output relationship for incremental knee‐extensor ergometry

Introduction: The purpose of this investigation was to determine the reproducibility of the log‐transformed model for electromyography (EMG) amplitude during incremental single‐leg knee‐extensor exercise. Methods: Eight healthy college‐aged men performed 3 incremental tests on separate occasions on a knee‐extensor ergometer. EMG amplitude was analyzed for each participant on each occasion for the rectus femoris and vastus medialis muscles at 4 different exercise power outputs (30%, 50%, 70%, and 90%) corresponding to each participant's maximal power output. Intraclass correlation coefficients (ICC) were determined for the slope and y‐intercept terms derived from the log‐transformed EMG amplitude‐power output relationship for each muscle. Results: The ICC values for the rectus femoris (slope = 0.779; y‐intercept = 0.787) and vastus medialis (slope = 0.756; y‐intercept = 0.763) muscles were high. Conclusions: The log‐transformed EMG amplitude‐power output relationship is a reliable index for measuring motor unit activation. Muscle Nerve 52:428–434, 2015     

Functional impact of vibratory proprioceptive assistance in patients with facioscapulohumeral muscular dystrophy

Introduction: In this study we analyzed the effects of a rehabilitation method based on the use of vibratory proprioceptive assistance (VPA) in subjects with facioscapulohumeral muscular dystrophy. Methods: Eight subjects were given 1 month of mechanical vibratory treatment that consisted of 8 sessions of 40‐min stimulation on the more affected side. During each session, illusory movements were induced as follows: sensations of extension or flexion of the forearm or elevation of the arm via vibration applied to the distal tendon of the biceps brachialis (BB), triceps brachialis (TB), or pectoralis major muscles (PM), respectively, and of elevation of the arm with extension or flexion of the forearm via vibration of PM+BB or PM+TB, respectively. Results: Treatment led to a significant increase in the amplitude of voluntary shoulder flexion, constant score, and self‐rated health. Conclusion: VPA may serve as a rehabilitation method for reducing the deleterious effects of decline in motor activities. Muscle Nerve 52 : 780–787, 2015     

Pre‐morbid type 2 diabetes mellitus is not a prognostic factor in amyotrophic lateral sclerosis

Introduction: The aim of this study was to determine whether a history of pre‐morbid type 2 diabetes mellitus (DM2) is a prognostic factor in amyotrophic lateral sclerosis (ALS). Methods: The relationship between DM2 and survival was analyzed in a study population consisting of 1,322 participants from 6 clinical trials. Results: Survival did not differ by diabetes status (log‐rank test, P = 0.98), but did differ by body mass index (BMI) (log‐rank test, P = 0.008). In multivariate analysis, there was no significant association between diabetes and survival (P = 0.18), but the risk of reaching a survival endpoint decreased by 4% for each unit increase in baseline BMI (HR 0.96, 95% CI 0.94–0.99, P = 0.001). DM2 was less prevalent among ALS clinical trial participants than predicted. Conclusions: A history of pre‐morbid DM2 is not an independent prognostic factor in ALS clinical trial databases. The low DM2 prevalence rate should be examined in a large, prospective study to determine whether DM2 affects ALS risk. Muscle Nerve 52:339–343, 2015     

Stroke‐related effects on maximal dynamic hip flexor fatigability and functional implications

Introduction: Stroke‐related changes in maximal dynamic hip flexor muscle fatigability may be more relevant functionally than isometric hip flexor fatigability. Methods: Ten chronic stroke survivors performed 5 sets of 30 hip flexion maximal dynamic voluntary contractions (MDVC). A maximal isometric voluntary contraction (MIVC) was performed before and after completion of the dynamic contractions. Both the paretic and nonparetic legs were tested. Results: Reduction in hip flexion MDVC torque in the paretic leg (44.7%) was larger than the nonparetic leg (31.7%). The paretic leg had a larger reduction in rectus femoris EMG (28.9%) between the first and last set of MDVCs than the nonparetic leg (7.4%). Reduction in paretic leg MDVC torque was correlated with self‐selected walking speed (r² = 0.43), while reduction in MIVC torque was not (r² = 0.11). Conclusions: Reductions in maximal dynamic torque of paretic hip flexors may be a better predictor of walking function than reductions in maximal isometric contractions. Muscle Nerve 51 : 446–448, 2015     

Early‐stage development of human induced pluripotent stem cell‐derived neurons

Recent advances in human induced pluripotent stem cells (hiPSCs) offer new possibilities for biomedical research and clinical applications. Differentiated neurons from hiPSCs are expected to be useful for developing novel methods of treatment for various neurological diseases. However, the detailed process of functional maturation of hiPSC‐derived neurons (hiPS neurons) remains poorly understood. This study analyzes development of hiPS neurons, focusing specifically on early developmental stages through 48 hr after cell seeding; development was compared with that of primary cultured neurons derived from the rat hippocampus. At 5 hr after cell seeding, neurite formation occurs in a similar manner in both neuronal populations. However, very few neurons with axonal polarization were observed in the hiPS neurons even after 48 hr, indicating that hiPS neurons differentiate more slowly than rat neurons. We further investigated the elongation speed of axons and found that hiPS neuronal axons were slower. In addition, we characterized the growth cones. The localization patterns of skeletal proteins F‐actin, microtubule, and drebrin were similar to those of rat neurons, and actin depolymerization by cytochalasin D induced similar changes in cytoskeletal distribution in the growth cones between hiPS neurons and rat neurons. These results indicate that, during the very early developmental stage, hiPS neurons develop comparably to rat hippocampal neurons with regard to axonal differentiation, but the growth of axons is slower. © 2015 The Authors. Journal of Neuroscience Research Published by Wiley Periodicals, Inc.     

Comparison of long-term outcomes between children with aplastic anemia and refractory cytopenia of childhood who received immunosuppressive therapy with antithymocyte globulin and cyclosporine

The 2008 World Health Organization classification proposed a new entity in childhood myelodysplastic syndrome, refractory cytopenia of childhood. However, it is unclear whether this morphological classification reflects clinical outcomes. We retrospectively reviewed bone marrow morphology in 186 children (median age 8 years; range 1–16 years) who were enrolled in the prospective study and received horse antithymocyte globulin and cyclosporine between July 1999 and November 2008. The median follow-up period was 87 months (range 1–146 months). Out of 186 patients, 62 (33%) were classified with aplastic anemia, 94 (49%) with refractory cytopenia of childhood, and 34 (18%) with refractory cytopenia with multilineage dysplasia. Aplastic anemia patients received granulocyte colony-stimulating factor more frequently and for longer durations than other patients (P<0.01). After six months, response rates to immunosuppressive therapy were not significantly different among the 3 groups. Acquisition of chromosomal abnormalities was observed in 5 patients with aplastic anemia, 4 patients with refractory cytopenia of childhood, and 3 patients with refractory cytopenia with multilineage dysplasia. Although the cumulative incidence of total clonal evolution at ten years was not significantly different among the 3 groups, the cumulative incidence of monosomy 7 development was significantly higher in aplastic anemia than in the other groups (P=0.02). Multivariate analysis revealed that only granulocyte colony-stimulating factor administration duration of 40 days or more was a significant risk factor for monosomy 7 development (P=0.02). These findings suggest that even the introduction of a strict morphological distinction from hypoplastic myelodysplastic syndrome cannot eradicate clonal evolution in children with aplastic anemia.