Side of lesion influences interhemispheric inhibition in subjects with post-stroke hemiparesis

OBJECTIVE: To examine changes in interhemispheric inhibition (IHI) during homologous muscle activation in healthy subjects and in people with hemiparesis. METHODS: IHI in the abductor pollicus brevis (APB) muscle was examined using paired transcranial magnetic stimulation. Stimuli were delivered while the target APB was at rest or activated, and while the non-target contralateral APB was at rest or activated. RESULTS: In control subjects, IHI in the resting target APB was enhanced during activation of the contralateral APB, and was greater from the dominant hemisphere to the non-dominant. In stroke subjects, IHI in the non-affected APB was not modulated during voluntary activation of the affected APB, but was influenced by the prior dominance of affected hemisphere. Bilateral muscle activation did not elicit any changes in IHI in either group. CONCLUSIONS: IHI is asymmetrical between hemispheres but only when the target muscle is at rest. Subjects with stroke have an impaired ability to modulate IHI during unilateral muscle activation. SIGNIFICANCE: In people with stroke, the extent and modulation of interhemispheric transfer is influenced by the prior dominance of the affected hemisphere. This may impact on the efficacy of treatment interventions incorporating bilateral activation.     

脑卒中患者吞咽障碍及康复效果影像学研究

目的探讨电视X线透视吞咽功能检查（videofluoroscopic swallowing study,VFSS）在脑卒中患者吞咽功能评估中的应用价值,观察脑卒中后吞咽障碍发生情况,康复前后患者吞咽功能变化.方法脑卒中患者70例及健康成人80名分别作为研究组与对照组均进行VFSS,比较两组误吸等VFSS异常征象的发生情况.对发现误吸患者进行吞咽功能康复训练4周,训练后复查VFSS,比较训练前后吞咽异常的发生情况变化.结果对照组渗透或误吸、口腔滞留、咽腔滞留的发生率为5.0%,13.4%,25.3%.主要为轻度渗透及口咽腔滞留.研究组渗透或误吸、口腔滞留、咽腔滞留发生率为45.0%,46.5%,48.9%,主要为重度渗透或误吸,中重度口咽腔滞留.其中隐匿性误吸为10次（占总误吸的24.4%）.误吸患者康复治疗后渗透或误吸发生率较康复治疗前减少（P＜0.05）.结论脑卒中后吞咽障碍在康复期仍较为常见,可表现为多种影像学异常.VFSS可确切诊断吞咽异常,进行针对性康复训练,使患者吞咽功能提高.     

脑卒中后肩-手综合征的危险因素分析

目的　探讨脑卒中后肩 手综合征的危险因素 ,为预防其发生提供依据。方法　 2 0 0 1年 8月至 2 0 0 3年 4月期间 ,对病程≤ 3个月的 10 3例脑卒中患者 ,发生肩 手综合征的可能危险因素进行回归分析。结果　肩 手综合征的患病率为 30 1% ,通过Logistic回归分析发现 :肩关节半脱位和年龄是其危险因素。结论　肩 手综合征是卒中后 3个月内一种常见的并发症 ,应针对危险因素 ,早期采取预防措施 ,尽可能减少其发生。     

国产A型肉毒毒素治疗脑卒中后上肢痉挛的疗效

目的探讨国产A型肉毒毒素(CBTX-A)肌肉注射治疗脑卒中后上肢痉挛的疗效和安全性。方法选取43例脑卒中患者为研究对象。根据随机数字表将患者分为两组:CBTX-A +康复治疗组(治疗组)和单纯康复治疗组(对照组)。治疗组患者除康复训练外,肱二头肌肌肉注射CBTX- A。分别于治疗前及治疗后2、4、8、12周对患者上肢功能进行评价。评价内容包括改良的Ashworth计分(MAS)、关节活动度(ROM)、上肢的Fugl-Meyer(FMA-上肢)计分和上肢的FIM运动能力(mot- FIM-上肢)。结果治疗组CBTX-A局部注射治疗后,85.7%(18/21)的患者有效。两组在MAS、ROM、FMA-上肢计分和mot-FIM-上肢方面,治疗后比治疗前均有显著改善。治疗后2、4、8周MAS计分治疗组分别为1.74±0.41,1.62±0.35,1.60±0.41,对照组分别为2.50±0.51,2.27±0.53, 2.18±0.55,各期两组间差异有统计学意义(P<0.01)。但是在治疗后12周时,两组间差异无统计学意义(P>0.05)。治疗后4-12周,ROM计分治疗组分别为57.81±57.60,66.43±64.38,68.14±65.99,对照组分别为27.91±30.13,30.73±34.03,33.73±34.50,各期治疗组比对照组均有显著性增加,差异有统计学意义(P<0.05)。治疗组治疗后FMA-上肢计分和mot-FIM-上肢计分与对照组相比均无统计学意义(P>0.05)。结论通过实验可以得出CBTX-A肌肉注射结合康复治疗可以达到提前缓解局部肌张力,扩大关节活动度,减轻疼痛,改善肢体功能的目的,这种治疗方法安全有效,具有良好的耐受性。     

Virtual reality treatment and assessments for post-stroke unilateral spatial neglect: A systematic literature review

Unilateral spatial neglect (USN) is a highly prevalent post-stroke deficit. Currently, there is no gold standard USN assessment which encompasses the heterogeneity of this disorder and that is sensitive to detect mild deficits. Similarly, there is a limited number of high quality studies suggesting that conventional USN treatments are effective in improving functional outcomes and reducing disability. Virtual reality (VR) provides enhanced methods for USN assessment and treatment. To establish best-practice recommendations with respect to its use, it is necessary to appraise the existing evidence. This systematic review aimed to identify and appraise existing VR-based USN assessments; and to determine whether VR is more effective than conventional therapy. Assessment tools were critically appraised using standard criteria. The methodological quality of the treatment trials was rated by two authors. The level of evidence according to stage of recovery was determined. Findings were compiled into a VR-based USN Assessment and Treatment Toolkit (VR-ATT). Twenty-three studies were identified. The proposed VR tools augmented the conventional assessment strategies. However, most studies lacked analysis of psychometric properties. There is limited evidence that VR is more effective than conventional therapy in improving USN symptoms in patients with stroke. It was concluded that VR-ATT could facilitate identification and decision-making as to the appropriateness of VR-based USN assessments and treatments across the continuum of stroke care, but more evidence is required on treatment effectiveness.     

Cross-sectional study of quadriceps properties and postural stability in patients with chronic stroke and limited vs. non-limited community ambulation

Background: Changes in the paretic-side metabolism post-stroke and quadriceps muscle mechanical properties favour muscle wasting, affecting postural instability and walking impairment. Further clarification is needed in subjects post-stroke who show limited or non-limited community ambulation.

Objectives: To analyze between-limb differences in quadriceps muscle thickness, strength and thigh cutaneous temperature, as well as investigate postural stability in subjects with chronic stroke and limited vs. non-limited community ambulation and compared against healthy controls.

Methods: In this controlled cross-sectional study, 26 participants with chronic hemiparesis post-stroke (divided in a slow gait group (SG<0.8 m/s) (n = 13) and a fast gait group with full community ambulation speed (FG≥0.8 m/s)) and 18 healthy people were recruited. Thigh surface temperature, rectus femoris (RF) and vastus intermedius (VI) muscles thickness, quadriceps’ isometric maximal voluntary contraction and postural stability were measured.

Results: The SG presented significantly lower RF (P = .019) and VI (P = .006) muscle thickness, less peak force (P < .001) and lower temperature (P = .002) in the paretic vs the non-paretic limb. The FG showed significantly lower VI thickness (P = .036) and peak force (P < .001) in the paretic vs the non-paretic limb. Regarding balance, all indices were worse in the SG versus the FG and CG.

Conclusions: Subjects of the FG, despite showing full community ambulation speed, had less quadriceps strength and VI muscle thickness but not RF muscle wasting in the paretic limb. The paretic VI muscle wasting may be an important factor to reach normal walking. The SG showed between-limb differences in all the studied variables and the worst postural stability.     

Classifying physical activity research following stroke using the behavioral epidemiologic framework

Abstract

Background:

Stroke is a significant public health issue in the USA and a need emerges to better understand how to reduce an individual's co-morbidity risk. Physical activity is one approach to improving the health of individuals and comprehensive literature supports increased activity as a means to reduce risk of morbidity and mortality. One approach to examining whether research in a field is addressing a public health issue is through application of the behavioral epidemiological framework.

Objective:

To classify physical activity research for individuals following stroke into distinct phases so that efforts can be made to systematically address gaps and disseminate evidence-based practice.

Methods:

Specific key words were identified and then searched through EBSCOhost, PubMed, and Google Scholar. Physical activity and stroke literature from 2000–2014 was categorized into one of five discrete phases. Research in Phase 1 identified associations between activity and health; Phase 2 established valid measures of activity; Phase 3 examined determinants of behavior; Phase 4 evaluated activity interventions; and Phase 5 disseminated evidence-based practice.

Results:

A comprehensive review of literature identified 202 articles with 70% categorized in Phase 1 (n?=?141), 11% in Phase 2 (n?=?23), 10% in Phase 3 (n?=?20), 8% in Phase 4 (n?=?15), and 1% in Phase 5 (n?=?3).

Conclusion:

Findings suggest that physical activity research for individuals following stroke is in the early stages of development with less than 10% of research evaluating or disseminating interventions.     

脑卒中后抑郁大鼠海马原位增殖的新生细胞存活和分化状态

目的 观察脑卒中后抑郁(post-stroke depression,PSD)大鼠海马原位增殖新生细胞的存活和分化.方法 采用左侧大脑中动脉阻塞(MCAO)联合慢性不可预见温和应激刺激(chronicmild stress,CMS)及孤养法建立PSD模型,将雄性SD大鼠分为假手术、脑卒中、CMS和PSD组.每组均为18只.采取免疫组织化学、荧光双标染色及共聚焦成像动态检测,比较各研究组大鼠左侧海马齿状回溴脱氧尿苷嘧啶(BrdU)及其与神经元特异性核蛋白(NeuN)或胶质纤维酸性蛋白(GFAP)共表达.结果 与脑卒中组(232.2±8.6、123.7±2.6、136.2±2.6)相比,PSD组大鼠左侧(伤侧)海马齿状回BrdU+细胞数在脑梗死后第21(156.2±2.5)、30(70.2±2.0)和45天(81.2±1.1)均明显减少(t=28.83、52.2、62.08,均P<0.01),但仍高于假手术组.与脑卒中组(79.3%±2.8%、87.7%±4.6%)相比,PSD组大鼠左侧(伤侧)海马齿状回BrdU+/NeuN+细胞比例在脑梗死后第30(69.0%±3.4%)和45天(78.3%±2.4%)均明显减少(t=5.871、4.403,均P<0.01).BrdU+/GFAP+细胞比例在脑梗死后30和45 d均明显增加(t=4.226、8.945,P<0.01).结论 PSD大鼠脑卒中后海马齿状回原位增殖的新生细胞存活降低,分化为神经元的比例下降,胶质细胞比例增加.     

Gait quality and velocity influences activity tracker accuracy in individuals post-stroke

Objective: Fitbit Zip? (FBZ) is a low-cost user-friendly device that could help motivate individuals post-stroke to increase their physical activity. However, inaccuracy in step counts from altered gait variables could cause dissatisfaction and reduce compliance. The aim of this study was to determine the influence of gait variables on the concurrent validity of the FBZ.

Method: In a cross-sectional study, 19 community-dwelling stroke survivors (mean 66 (SD 8) years) wore a FBZ at the non-paretic hip, and were videoed completing a six minute walk test (6MWT). Steps recorded by the FBZ were compared against the criterion standard of manually counted steps from video-recordings. Spatio-temporal gait parameters were calculated, and gait quality was assessed using the Wisconsin Gait Analysis (WGA) tool. Concurrent validity of FBZ was determined using Kendall’s Tau correlation coefficient. Linear regression analysis determined the association between gait parameters, quality, and FBZ accuracy.

Results: A very strong correlation was observed between the FBZ steps and manual counting (τ = 0.80, p < .001). Step difference demonstrated significant negative association with gait velocity (R² = 0.35, B = ?59.94, p = .007), and positive association with WGA score (R² = 0.69, B = 4.59, p < .001), indicating poor FBZ accuracy in participants with lower speed (≤0.8m/s) and poor gait quality (WGA score>16).

Conclusions: FBZ is an accurate measure of step activity in independent ambulators with stroke walking at speeds > 0.8m/s, but accuracy can be compromised with lower speed and poor gait quality. Clinicians should consider gait velocity and quality before advising FBZ as a motivational tool to increase physical activity in individuals post-stroke.     

Physiological alterations of maximal voluntary quadriceps activation by changes of knee joint angle

The purpose of this study was to investigate the influence of different angles of the knee joint on voluntary activation of the quadriceps muscle, estimating the ability of a subject to activate a muscle maximally by means of voluntary contraction. Isometric torque measurement was performed on 6 healthy subjects in 5 degrees intervals between 30 degrees and 90 degrees of knee joint flexion. Superimposed twitches at maximal voluntary contraction (MVC) and at a level of 60% and 40% of the MVC were applied and the voluntary activation estimated. At between 30 degrees and 75 degrees of knee flexion, the maximal extension torque increased at an average rate of 2.67 +/- 0.6 Nm/degree, followed by a decline with further flexion. However, throughout the joint-angle range tested, voluntary activation increased on average by 0.37%/degree with a maximum at 90 degrees of flexion. Due to the influence of joint position it is not possible to generalize results obtained at the knee joint angle of 90 degrees of flexion, which is usually used for the quadriceps twitch-interpolation technique. Consequently, it is useful to investigate voluntary activation deficits in knee joint disorders at a range of knee joint angles that includes, in particular, the more extended joint angles used frequently during daily activity.     

脑卒中后抑郁大鼠海马齿状回5-羟色胺1A受体的表达

目的 观察脑卒中后抑郁(PSD)大鼠海马齿状回5-羟色胺1A(5-HT1A)受体的表达.方法 将SD雄性大鼠分为正常对照组、卒中组、应激抑郁对照组和PSD组,每组6只.应用左侧大脑中动脉阻塞(MCAO)联合不可预见的慢性温和应激(CMS)刺激及孤养法建立PSD大鼠模型,采用荧光实时定量聚合酶链反应和Western印迹法检测并比较各组大鼠CMS第19天和第28天齿状回5-HT1A受体(mRNA)和蛋白表达水平.结果 (1)CMS第19天,PSD组5-HT1A受体mRNA表达(O.012±0.001)低于正常对照组(0.361±0.010)和卒中组(0.039±0.002;P＜0.001);其5-HT1A受体蛋白表达(0.400±0.030)低于正常组(1.320±0.060)和卒中组(0.610±0.060;均P＜0.001).(2)CMS第28天,PSD组5-HT1A受体mRNA(0.013±0.001)低于正常对照组(0.336±0.011)、卒中组(0.063±0.006;均P＜0.001);其5-HT1A受体蛋白表达(0.080±0.020)低于正常组(0.620 ±0.030)、卒中组(0.260±0.040)和应激抑郁组(0.320±0.020;均P＜0.001).结论 PsD大鼠海马齿状回5-HT1A受体表达水平降低,此改变可能是PSD发病的分子机制之一.     

Assessment of the reliability of central and peripheral fatigue after sustained maximal voluntary contraction of the quadriceps muscle

The aim of the present study was to further confirm the validity of measurements for characterizing neuromuscular alterations by establishing their reliability both before and after fatigue. Thirteen men (28 +/- 5 years) volunteered to participate in two separate identical sessions requiring the performance of a sustained maximal voluntary contraction (MVC) with the quadriceps muscle for 2 min. MVC and transcutaneous electrical stimulations were used before and immediately after the fatiguing contraction to investigate the reliability of MVC torque, central activation, and peripheral variables (M-wave properties, peak twitch, peak doublet) within and between sessions. Based on previous and present results, we advise the use of (1) voluntary activation level with potentiated doublet as a reference to describe central fatigue, (2) electromyographic activity of vastus lateralis muscle as a surrogate for quadriceps for both voluntary and evoked contraction, and (3) potentiated peak doublet amplitude to investigate contractile fatigue. These findings can be useful in the choice of the parameters describing central and peripheral fatigue of the quadriceps muscle in future studies.     

Effects of the combination of respiratory muscle training and abdominal drawing-in maneuver on respiratory muscle activity in patients with post-stroke hemiplegia: a pilot randomized controlled trial

Abstract

Purpose:

No study has examined the effects of the combination of respiratory muscle training (RMT) and abdominal drawing-in maneuver (ADIM) on respiratory muscle activity and function in stroke patients during early pulmonary rehabilitation. The purpose of this study was to investigate the effects of RMT combined with ADIM on decreased respiratory muscle activity and function in patients with post-stroke hemiplegia.

Methods:

Thirty-seven subjects with post-stroke hemiplegia were randomly allocated to three groups; integrated training group (ITG), respiratory muscle training group (RMTG), and control group (CG). All of the subjects received routine therapy for stroke rehabilitation for 1 hour, five times a week for 6 weeks. Especially, the ITG received RMT using an incentive respiratory spirometer and ADIM using a Stabilizer, and the RMTG only received RMT using incentive respiratory spirometer for 15?minutes a day, five times a week for 6 weeks. Pulmonary function was evaluated using spirometry for measuring the forced vital capacity (FVC) and force expiratory volume in 1?second (FEV₁). Additional surface electromyography (sEMG) analysis was included by measuring the respiratory muscle activity.

Results:

Our results showed that changes between the pre- and post-test values of FVC (F?=?12.50, P?=?0.02) and FEV₁ (F?=?12.81, P?=?0.01) (P?<?0.05) in the ITG were significantly (P?<?0.05) greater. Changes in EMG activation of the diaphragm (F?=?13.75, P?=?0.003) and external intercostal (F?=?14.33, P?=?0.002) (P?<?0.01) muscles of patients in the ITG during maximal static inspiratory efforts were significantly (P?<?0.05) greater than those in patients of the RMTG and the CG at post-test.

Conclusions:

Our findings suggested that RMT combined with ADIM could improve pulmonary function in patients with post-stroke hemiplegia.     

Recording activity in proximal muscle networks with surface EMG in assessing infant motor development

ObjectiveTo develop methods for recording and analysing infant’s proximal muscle activations.MethodsSurface electromyography (sEMG) of truncal muscles was recorded in three months old infants (N = 18) during spontaneous movement and controlled postural changes. The infants were also divided into two groups according to motor performance. We developed an efficient method for removing dynamic cardiac artefacts to allow i) accurate estimation of individual muscle activations, as well as ii) quantitative characterization of muscle networks.ResultsThe automated removal of cardiac artefacts allowed quantitation of truncal muscle activity, which showed predictable effects during postural changes, and there were differences between high and low performing infants. The muscle networks showed consistent change in network density during spontaneous movements between supine and prone position. Moreover, activity correlations in individual pairs of back muscles linked to infant́s motor performance.ConclusionsThe hereby developed sEMG analysis methodology is feasible and may disclose differences between high and low performing infants. Analysis of the muscle networks may provide novel insight to central control of motility.SignificanceQuantitative analysis of infant’s muscle activity and muscle networks holds promise for an objective neurodevelopmental assessment of motor system.     

Short-term effect of a close-fitting type of walking assistive device on spinal cord reciprocal inhibition

One of the major problems with walking encountered by patients with spastic hemiplegia is diminished toe clearance due to spasticity of their leg muscles. To improve their walking, a specialized robot assist for ankle movements (RE-Gait) has been utilized. The present study examined the neurophysiological effects whether spinal cord reciprocal Ia inhibition (RI) in the leg was altered by using RE-Gait. Sixteen patients with a clinical diagnosis of stroke were divided into the two groups, RE-Gait walking group (Group R) and normal (controlled) walking group (Group C). In each group, they walked on a flat floor for 15 min with or without RE-Gait. The depression of soleus (Sol) H-reflexes conditioned by common peroneal nerve stimuli with the conditioning-test (C-T) intervals of 1, 2, 3, and 4 ms were assessed before and immediately after each walking session. After the intervention, the LSM (SE) of Sol H-reflex amplitude with 1, 2 and 3 ms C-T interval conditions were significantly decreased in group R (1 ms: 88.15 (4.60), 2 ms: 86.37 (4.60), 3 ms: 89.68 (4.62)) compared to group C (1 ms: 105.57 (4.56), 2 ms: 100.89 (4.58), 3 ms: 107.72 (4.58)) [1 ms: p = 0.012, 2 ms: p = 0.035, 3 ms: p = 0.011]. Walking assistive robot that targets ankle movements might be a new rehabilitation tool for regulating spinal cord excitability.