注意训练对非流畅性失语患者双任务范式干扰效应影响的功能磁共振研究

目的考察注意训练对非流畅性失语患者汉字加工任务中双任务范式干扰效应的激活区及偏侧化指数的影响。方法将20例脑卒中后非流畅性失语患者分成实验组及对照组各10例,分别给予注意训练和认知训练,每次30 min,每周5次,共4周。训练前后分别采用组块设计对患者汉字加工任务进行功能磁共振扫描,比较训练前后双任务范式干扰效应的激活区及偏侧化指数。结果训练前两组患者均为右侧额下回、双侧顶叶、双侧小脑显著激活;训练后,实验组各激活区更加显著,而对照组各激活区未见显著变化;训练前两组患者均呈右半球优势;训练后实验组呈左半球优势,而对照组仍呈右半球优势。结论在双任务范式干扰效应中,右侧额下回、双侧顶叶、双侧小脑可能在知觉注意阶段对解决双重任务干扰非常重要;注意训练后激活更加显著;注意训练可能使失语症患者语义加工产生了功能重组。     

DUAL-TASK ASSESSMENT IMPLICATIONS FOR ANTERIOR CRUCIATE LIGAMENT INJURY: A SYSTEMATIC REVIEW

Background:Several systematic reviews have evaluated the role of dual-task assessment in individuals with concussion. However, no systematic reviews to date have investigated dual-task protocols with implications for individuals with anterior cruciate ligament (ACL) injury or ACL reconstruction (ACLR).Purpose:To systematically review the evidence on dual-task assessment practices applicable to those with ACL deficiency/ACLR, specifically with the aim to identify motor-cognitive performance costs.Study Design:Systematic reviewMethods:A systematic literature review was undertaken on those with ACL-deficient or ACL-reconstructed knees performing dual-task activities. The following databases were searched from inception to June 8, 2018 including CINAHL, PsychInfo, PubMed, SPORTDiscus, Web of Science, and gray literature. Three primary search categories (knee, cognition, and motor task) were included. Only one reviewer independently performed the database search, data extraction, and scored each article for quality. All studies were assessed for quality and pertinent data were extracted, examined and synthesized.Results:Ten studies were included for analysis, all of which were published within the prior ten years. Performance deficits were identified in those with either ACL deficiency or ACLR while dual-tasking, such as prioritization of postural control at the expense of cognitive performance, impaired postural control in single limb stance, greater number of cognitive errors, and increased step width coefficient of variation while walking. No studies examined those with prior ACL injury or ACLR during tasks that mimicked ACL injury mechanisms such as jump-landing or single-leg cutting.Conclusion:The results of the current systematic review suggests that postural control, gait, and/or cognitive deficits exist when evaluated under a dual-task paradigm in those with ACL deficiency or ACLR. This systematic review highlights the need for future research on dual-task assessment for individuals who have sustained an ACL injury or undergone ACLR, specifically utilizing more difficult athletic movements.Level of Evidence:Level 3a     

The attentional cost of external rhythmical cues and their impact on gait in Parkinson’s disease: effect of cue modality and task complexity

Summary Changes in gait performance in 153 subjects with PD using three rhythmical cues (auditory, visual and somatosensory) were measured during a simple walking task and a dual walking task in the home. Subjects were ‘on’ medication and were cued at preferred step frequency. Accelerometers recorded gait and walking speed, step amplitude and step frequency were determined from raw data. Data were analysed with SAS using linear regression models. Gait performance during a single task reduced with cues in contrast to a dual task where PD subjects appeared to benefit from rhythmical cues (increased speed and step length). Effects were dependent on cue modality with significant improvements for auditory cues compared to others. A significant short-term carry-over effect of cues reduced 3 weeks later. Cues may reduce attentional demands by facilitating attentional allocation, accounting for differences of cue seen during single and dual task. Furthermore cue modality may influence attentional demand which is an important consideration for rehabilitation.     

基于严肃游戏的双重任务训练对养老机构轻度认知障碍老年人的干预效果

目的 评价基于严肃游戏的双重任务训练对养老机构轻度认知障碍老年人的干预效果。方法 将60例养老机构轻度认知障碍老年人按照居住的社会福利院分为对照组和干预组各30例。对照组采取常规的生活照护及文体娱乐活动干预,干预组在对照组的基础上给予基于严肃游戏的平板游戏及有氧运动双重任务训练12周。结果 干预组和对照组分别25例、26例老年人完成研究。干预后,干预组简版老年抑郁量表评分显著低于对照组,蒙特利尔认知评估量表评分及生活质量简表的生理总评分、心理总评分显著高于对照组(均P<0.05),两组日常生活能力量表评分差异无统计学意义(P>0.05)。结论 基于严肃游戏的双重任务训练有助于提高养老机构轻度认知障碍老年人的认知功能,改善抑郁情绪,提高生活质量。     

Relationships between gait variability and ambulatory activity post stroke

Background: Fall risk and balance confidence are related to gait variability and ambulatory activity post stroke, yet whether a relationship exists between gait variability and ambulatory activity is unknown. Knowing if gait variability measured under naturalistic conditions is related to ambulatory activity could explain more about the relationship between falls and walking activity post-stroke.

Objectives: To examine relationships between spontaneous, daily ambulatory activity and gait variability during single- and dual-task walking, in low- and high-distraction settings in adults post stroke.

Methods: Sixteen community-dwelling adults post stroke participated in a cross-sectional study. Spatiotemporal gait parameters were recorded during single- and cognitive-motor dual-task walking in low- and high-distraction settings. Coefficient of variation was calculated for stride length and stride duration. Average walking bout duration, maximum walking bout duration, and total number of steps per day were captured using an activity monitor. Correlations between ambulatory activity measures and gait variability were examined.

Results: In the high-distraction setting, single-task stride duration variability was negatively related to all three ambulatory activity measures, but the strongest relationship was a negative correlation between dual-task stride duration variability and average walking duration. In the low-distraction setting, single-task stride duration variability was negatively related to maximum walking duration. None of the other variability measures were related to ambulatory activity.

Conclusions: The finding that stride duration variability in a high-distraction environment, with or without an additional cognitive task, is related to ambulatory activity in community-dwelling stroke survivors suggests that assessments incorporating attentional demands of real-world walking may be useful additions to clinical practice.     

Biomechanical and cognitive interactions during Visuo Motor Targeting Task

BackgroundBiomechanical analyses primarily focus on physical aspects of human movement; however, it is not understood how walking is affected while simultaneously performing a demanding cognitive task - a form of Cognitive-Motor Interference (CMI). CMI occurs when performance of a primary task (e.g. walking) is affected following the introduction of a cognitive task (e.g. visual search).Research questionWould Visuo Motor Targeting Task (VMTT) impair visual search performance and reduce the margin of stability (MoS) at higher gait speeds?MethodsA protocol was developed to investigate responses of the neuromuscular system while performing a complex visual search task. The Computer Assisted Rehabilitation ENvironment (CAREN, Motekforce Link, Netherlands) system was used for the experimental design. Twenty male participants (Age = 24.2 ± 2.5yrs, Weight = 70.3 ± 10.6 kg, Height = 178.0 ± 9.1 cm) located and pointed towards targets in complex scenes while walking at different gait speeds (0.55, 1.11 and 1.67 m/s.) or while stationary. The cost of visual search during a Visuo Motor Targeting Task (VMTT) was based on the pointing accuracy during the visual search task.ResultsA two-way repeated measure ANOVA showed that MoS in the ML direction significantly improved with increased gait speed and during the visual search task. There was also a significant interaction with MoS improvement being greater during the visual search task at high gait speeds. MoS in the AP was only affected by gait speed. Visual performance and cost of visual search were enhanced during walking versus standing up to 25 %.SignificanceThis study investigated CMI at different gait speeds, which may have implications in postural control, falls and other neurological disorders.     

The impact of a community-based food education programme on dietary pattern in patients with type 2 diabetes: Results of a pilot randomised controlled trial in Portugal

The purpose of this study was to analyse the effects of a food education programme, with easy-to-implement strategies integrated in a community-based exercise programme, on dietary pattern of patients with type 2 diabetes (T2D). Thirty-three patients (65.4 ± 5.9 years old) were engaged in a 9-month randomised controlled trial: a supervised exercise programme (control group [CON]; n = 15; combined exercise; three sessions per week; 75 min per session) or the same exercise programme plus a concomitant 16-week food education programme (experimental group [EXP]; n = 18; 15-min. group classes and dual-task strategies during exercise). Dietary pattern was assessed using a 3-day food record at baseline and at 9 months. The intake of total fat, polyunsaturated fat, and the daily servings of vegetables significantly increased in EXP compared with the CON group. Retention and adherence to the programme were 54% and 49.5 ± 27.2%, respectively. This food education programme improved dietary pattern of patients with T2D. Special attention should be given to strategies that support participants’ attendance.     

双任务干预改善健康老年人平衡功能效益的系统综述

目的 系统综述双任务干预对健康老年人平衡功能干预的有效性。     

Word form encoding is under attentional demand: evidence from dual-task interference in aphasia

Although speakers can go on producing utterances while doing concurrent tasks, language planning is affected in conditions of divided attention. It is however unclear whether a concurrent task impacts only lexical selection, or if post-lexical processing is also impacted. To elucidate this question, we reasoned that if an encoding process is under attentional control, this should be even more the case when the planning process is disrupted due to brain damage: increased error rates in left-hemisphere damaged participants under dual-task conditions should therefore shed light on which encoding processes need attentional resources. Twelve participants producing either predominantly lexical or phonological errors following left-hemisphere stroke and eleven matched healthy controls underwent a dual-task picture naming paradigm with a concurrent auditory verbal and non-verbal task. The results indicate an impact of active dual-tasks on word production in both controls and aphasic participants, but a magnified effect on errors in aphasic participants with an overall increase of phonological errors under dual-task conditions. These results suggest that post-lexical encoding processes are under attentional demand.     

Improving Dual-Task Control With a Posture-Second Strategy in Early-Stage Parkinson Disease

Objective

To examine the task prioritization effects on postural-suprapostural dual-task performance in patients with early-stage Parkinson disease (PD) without clinically observed postural symptoms.