Characterization of neuromuscular performances in adults with late-onset Pompe disease: A control case cross-sectional study.

Adults with late-onset Pompe disease (aLOPD) are characterized by muscular contractile tissue deterioration. However, their neuromuscular performances are poorly known. We aimed to compare maximal muscle strength, activation, explosive strength and neuromuscular fatigue between aLOPD and controls. We studied 20 aLOPD and 20 matched controls. Isometric maximum voluntary contraction (MVC) torque was obtained for the hip, knee and ankle muscles. The voluntary activation level (VAL) during knee extensor MVC was assessed using interpolated twitch technique. Explosive strength was evaluated for knee and ankle muscles through the rate of torque development (RTD) during fast contractions. Neuromuscular fatigue was measured during a 30-second contraction of knee flexors and extensors. All muscle MVC torques were significantly lower in aLOPD than controls (p <0.05). The weakest muscles were the hip extensors followed by hip abductors and abductors. Raw value of RTD was lower in aLOPD for the majority of muscles (p <0.05). No intergroup differences were reported for normalized RTD, VAL and neuromuscular fatigue (p-values> 0.05). Our study shows that maximal strength was the only neuromuscular characteristic affected in aLOPD with a proximal-distal intensity gradient. This suggests that the surviving muscle tissue of aLOPD is as functionally efficient as that of control individuals.

Determinants and Characterization of Locomotion in Adults with Late-Onset Pompe Disease: New Clinical Biomarkers.

BACKGROUND: The late-onset form of Pompe disease (LOPD) is characterized by muscle weakness, locomotor limitations and a risk of falls. The mechanisms responsible for altered locomotion in adults with LOPD are unknown. The identification of clinical biomarkers is essential for clinical follow-up and research. OBJECTIVES: To identify muscle determinants of impaired locomotor performance, gait stability and gait pattern, and biomechanical determinants of falls in adults with LOPD. METHODS: In this cross-sectional, case-control study, LOPD and control participants underwent 3D gait analysis, locomotor performance tests and muscle strength measurements (isokinetic dynamometer). We explored the muscular determinants of locomotor performance (gait speed, 6-minute walk test distance and timed up and go test), gait stability (spatiotemporal gait variables) and the gait pattern. We also explored biomechanical gait determinants of falls. After intergroup comparisons, determinants were sought to use forward stepwise multiple regression. RESULTS: Eighteen participants with LOPD and 20 control participants were included. Locomotor performance, gait stability, and the gait pattern were significantly altered in LOPD compared to control participants. Hip abductor strength was the main common determinant of locomotor performance, gait stability and pelvic instability. Hip flexor strength was the main determinant of abnormal gait kinematics at the hip and knee. Percentage duration of single support phase during the gait cycle was the main determinant of falls. CONCLUSIONS: Hip abductor strength and percentage duration of single support during gait were the major determinants of locomotor performance, gait stability, falls and the gait pattern in LOPD. These new clinical biomarkers should therefore be systematically assessed using instrumented tools to improve the follow-up of adults with LOPD. They should also be considered in future studies to accurately assess the effects of new therapies. Hip abductor strength and single support phase should also be priority targets for rehabilitation.

Motor Function Characteristics of Adults With Late-Onset Pompe Disease: A Systematic Scoping Review.

BACKGROUND AND OBJECTIVES: Pompe disease is a rare neuromuscular disease caused by a deficiency of the lysosomal enzyme acid α-glucosidase. The late-onset Pompe disease (LOPD) in adults is characterized by weakness of ventilatory, axial, and proximal extremity muscles. These muscle impairments progressively impair various motor functions such as locomotion and postural control. Nearly 87% of adults with LOPD (aLOPD) report walking problems, and more than 80% report instability and falls. Knowledge of these motor functions is now sufficient to provide a clear and comprehensive overview of motor function in aLOPD. Therefore, this scoping review aimed to summarize current knowledge about motor function in aLOPD. It specifically targeted neuromuscular performance, locomotion, and postural control. METHODS: A systematic search in MEDLINE (through PubMed), EMBASE, and Cochrane databases was conducted until May 2021. We included studies providing primary data on at least 4 participants, exploring neuromuscular performance, locomotion, and/or postural control in aLOPD. Risk of bias analysis was assessed using tools appropriate to the study designs; the risk of bias 2 (Cochrane tool) for randomized controlled trials, risk of bias in Nonrandomized Studies - of Interventions (Cochrane tool) for nonrandomized interventional trials, and the Newcastle-Ottawa Scale for cohort studies and case-control studies. RESULTS: The search identified 2,885 articles. After screening, 58 articles were included in the analysis. In these studies, 88% explored locomotion, 83% neuromuscular performance, and 3% postural control. This review showed that aLOPD experience symmetrical weakness, concerning especially the hip and lumbar muscles. Locomotor activities are limited with a distance reduction, spatiotemporal gait parameter modification, and an increased pelvic drop and tilt. Balance disorders are also observed especially in the anteroposterior direction. DISCUSSION: We performed the first review on motor function characteristics in aLOPD. Although a significant amount of knowledge was synthesized in this review, our study also highlighted the lack of current research on this topic. Maximal muscle strength was the only neuromuscular performance studied, and gait biomechanics and postural control were poorly explored in LOPD. Relationships between the degree of muscle weakness and motor function alterations also remain to be determined in aLOPD.

Self-rehabilitation combined with botulinum toxin to improve arm function in people with chronic stroke. A randomized controlled trial.

BACKGROUND: Botulinum toxin injection (BTI) reduces muscle hyperactivity, but its effect on active upper-limb function is limited. Intensive rehabilitation could optimize the effects; however, outpatient post-stroke rehabilitation is usually not intensive. One solution could be self-rehabilitation. OBJECTIVES: The aim of this randomized controlled trial was to determine the effect of a self-rehabilitation program combined with BTI on upper-limb function in individuals with chronic hemiparesis. METHODS: In total, 33 outpatients were randomly allocated to receive BTI+self-rehabilitation (R group: n=17) or BTI alone (C group: n=16). Outcomes evaluated just before the BTI and 4 weeks later included the Wolf Motor Function Test (WMFT time: primary outcome), Action Research Arm Test, fatigue and quality of life. RESULTS: Change in WMFT did not differ between groups at 4 weeks (WMFT time: -14% for R group, -4% for C group. WFMT score: +12% for R group, 0% in C group). WFMT time and score improved significantly in the R group only (-14%, P=0.01, and +12%, P=0.02). In addition, the proportion of patients with improved WMFT time and score was higher in the R than C group (R group: 71% improved score, 77% improved time; C group: 43% improved score, 50% improved time). Also, passive range of shoulder flexion (P=0.03) and wrist extension (P=0.01) improved only in the R group. No other variables changed significantly. Compliance was excellent; average daily training time was greater than that prescribed. CONCLUSIONS: The addition of a self-rehabilitation program to BTI did not significantly improve functional outcomes more than BTI alone; however, movement quality and speed improved only in the self-rehabilitation group. Participants in the self-rehabilitation group trained more than they were asked to, which suggests that they found the program worthwhile. These clinically relevant findings justify larger-scale studies of the effects of self-rehabilitation to enhance the effects of BTI. CLINICAL TRIAL: NCT02699762.