Effect of dual tasking on intentional vs. reactive balance control in people with hemiparetic stroke

Neurostimulation After Stroke

Neural stimulation technology aids stroke survivors in regaining lost motor functions. This article explores its applications in upper and lower limb stroke rehabilitation. The authors review various methods to target the corticomotor system, including transcranial direct current stimulation, repetitive transcranial magnetic stimulation, and vagus nerve stimulation. In addition, the authors review the use of peripheral neuromuscular electrical stimulation for therapeutic and assistive purposes, including transcutaneous electrical nerve stimulation, neuromuscular electrical stimulation, and functional electrical stimulation. For each, the authors examine the potential benefits, limitations, safety considerations, and FDA status.

Post-Stroke Functional Changes: In-Depth Analysis of Clinical Tests and Motor-Cognitive Dual-Tasking Using Wearable Sensors

Clinical tests like Timed Up and Go (TUG) facilitate the assessment of post-stroke mobility, but they lack detailed measures. In this study, 21 stroke survivors and 20 control participants underwent TUG, sit-to-stand (STS), and the 10 Meter Walk Test (10MWT). Tests incorporated single tasks (STs) and motor-cognitive dual-task (DTs) involving reverse counting from 200 in decrements of 10. Eight wearable motion sensors were placed on feet, shanks, thighs, sacrum, and sternum to record kinematic data. These data were analyzed to investigate the effects of stroke and DT conditions on the extracted features across segmented portions of the tests. The findings showed that stroke survivors (SS) took 23% longer for total TUG (p < 0.001), with 31% longer turn time (p = 0.035). TUG time increased by 20% (p < 0.001) from STs to DTs. In DTs, turning time increased by 31% (p = 0.005). Specifically, SS showed 20% lower trunk angular velocity in sit-to-stand (p = 0.003), 21% longer 10-Meter Walk time (p = 0.010), and 18% slower gait speed (p = 0.012). As expected, turning was especially challenging and worsened with divided attention. The outcomes of our study demonstrate the benefits of instrumented clinical tests and DTs in effectively identifying motor deficits post-stroke across sitting, standing, walking, and turning activities, thereby indicating that quantitative motion analysis can optimize rehabilitation procedures.

Effects of intensive multiplanar trunk training coupled with dual-task exercises on balance, mobility, and fall risk in patients with stroke: a randomized controlled trial

OBJECTIVE

We determined whether an exercise regime comprising high-intensity training, multiplanar trunk movements, and dual-task practice could improve trunk control, balance, functional mobility, and reduce fall risk in patients with hemiplegic stroke.

METHODS

In this randomized controlled trial, 74 patients (mean age 61.71 years) were randomly assigned to the experimental and comparison groups. Primary outcome was trunk impairment scale (TIS) scores. Secondary outcomes were scores on the Berg balance scale, 10-meter walk test, Timed-up-and-go test, timed-Up-Go-cognitive, and Stroke Impact Scale-16 to measure between-group changes from baseline. We used linear mixed modeling to identify changes over time within and between groups on each scale and whether changes persisted at 6- and 12-month follow-ups.

RESULTS

We observed significantly increased mean TIS scores from baseline to 3 months post-treatment (7.74); the increased scores were maintained at 6- and 12-month follow-ups (8.60 and 8.43, respectively). In the experimental group, all secondary outcomes showed significant and clinically meaningful results. Fall risk between groups was significantly reduced at 6 and 12 months.

CONCLUSIONS

Intensive multiplanar trunk movements coupled with dual-task practice promoted trunk control, balance, and functional recovery in patients with stroke, reduced fall risk, and improved independent mobility.Trial registration: #IRCT20200127046275N1.

Effect of Contextual Interference in the Practicing of a Computer Task in Individuals Poststroke

OBJECTIVES

Sensory and motor alterations resulting from stroke often impair the performance and learning of motor skills. The present study is aimed at investigating whether and how poststroke individuals and age- and sex-matched healthy controls benefit from a contextual interference effect on the practice of a maze task (i.e., constant vs. random practice) performed on the computer.

METHODS

Participants included 21 poststroke individuals and 21 healthy controls, matched by sex and age (30 to 80 years). Both groups were divided according to the type of the practice (constant or random) presented in the acquisition phase of the learning protocol. For comparison between the groups, types of practice, and blocks of attempts, the analysis of variance with Tukey's post hoc test (p < 0.05) was used.

RESULTS

Poststroke individuals presented longer movement times as compared with the control group. In addition, only poststroke individuals who performed the task with random practice showed improved performance at the transfer phase. Moreover, randomized practice enabled poststroke individuals to perform the transfer task similarly to individuals without any neurological impairment.

CONCLUSION

The present findings indicated a significant effect of contextual interference of practice in poststroke individuals, suggesting that applying randomized training must be considered when designing rehabilitation protocols for this population.

Cognitive-motor exergaming for reducing fall risk in people with chronic stroke: A randomized controlled trial

BACKGROUND

Dual-task (simultaneous motor and cognitive task) (DT) training via virtual-reality exergaming is known to benefit balance control post-stroke. However, the efficacy of such training on DT balance control (volitional and reactive) and cognitive (executive function and attention) domains associated with fall risk remains unclear.

OBJECTIVE

We evaluated the efficacy of cognitive-motor exergame training (CMT) (Wii-fit games in conjunction with cognitive tasks) for improving balance control (volitional and reactive) and cognition (executive function and attention) among people with chronic stroke (PwCS).

METHODS

Hemiparetic, ambulatory PwCS were randomly assigned to either CMT (n = 12) or conventional training (CT) (n = 12) and underwent six weeks of high-intensity, tapered balance training. The CMT group performed Wii-fit games in conjunction with cognitive tasks, while CT group underwent customized, progressive balance training. Performance under DT conditions on Limits of Stability (volitional) and Slip-Perturbation (reactive) tests, and letter-number sequencing (cognition) determined the efficacy of CMT.

RESULTS

Post-intervention, under DT reactive conditions, CMT group improved both motor and cognition, while the CT group improved motor alone. Under DT volitional conditions, motor performance improved only in CMT group.

CONCLUSION

Cognitive-motor exergaming appears to be effective for improving balance control and cognition and could be implemented in clinical stroke rehabilitation settings.

Timing of reactive stepping among individuals with sub-acute stroke: effects of 'single-task' and 'dual-task' conditions

Performance decrements in balance tasks are often observed when a secondary cognitive task is performed simultaneously. This study aimed to determine whether increased cognitive load resulted in altered reactive stepping in individuals with sub-acute stroke, compared to a reactive stepping trial with no secondary task. The secondary purpose was to determine whether differences existed between the first usual-response trial, subsequent usual-response trials, and the dual-task condition. Individuals with sub-acute stroke were exposed to external perturbations to elicit reactive steps. Perturbations were performed under a usual-response (single-task) and dual-task condition. Measures of step timing and number of steps were based on force plate and video data, respectively; these measures were compared between the usual-response and dual-task trials, and between the first usual-response trial, later usual-response trials (trials 2-5) and a dual-task trial. A longer time of unloading onset and greater number of steps were identified for the first usual-response trial compared to later usual-response trials. No significant differences were identified between usual-response and dual-task trials. Although improvements were observed from the first to subsequent usual-response lean-and-release trials, performance then tended to decrease with the introduction of the dual-task condition. These findings suggest that when introduced after usual-response trials, the dual-task trial may represent the first trial of a new condition, which may be beneficial in reducing the potential for adaptation that may occur after multiple repetitions of a reactive stepping task. Therefore, these findings may lend support to the introduction of a new condition (i.e. a dual-task trial) in addition to usual-response trials when assessing reactive balance in individuals with stroke.

Effect of Yoga practice on reducing cognitive-motor interference for improving dynamic balance control in healthy adults

OBJECTIVE

The purpose of our study was to investigate the effects of Yoga on reducing cognitive-motor interference (CMI) for maintaining balance control during varied balance tasks.

METHOD

Yoga (N=10) and age-similar non-practitioners (N=10) performed three balance tasks including the Limits of Stability test (LOS - Intentional balance), Motor Control test (MCT - Reactive balance), and Sensory Organization Test (SOT -condition 6: inducing both somatosensory and visual conflicts) under single-task (ST) and dual-task (DT, addition of a cognitive working memory task) conditions. The motor performance was assessed by recording the response time (RT) and movement velocity (MV) of the center of pressure (CoP) on LOS test, weight symmetry (WS) of CoP on the MCT test and equilibrium (EQ) of CoP on the SOT test. Cognitive performance was recorded as the number of correct responses enumerated in sitting (ST) and under DT conditions. The Motor cost (MC) and cognitive cost (CC) were computed using the formula ([ST-DT]/ST)*100 for all the variables. Greater cost indicates lower performance under DT versus ST condition.

RESULTS

The Yoga group showed a significantly lesser MC for both MCT and SOT tests (p<0.05) in comparison to their counterparts. The CC were significantly lower on LOS and MCT test for the Yoga group (p<0.05).

CONCLUSION

Results suggest that Yoga practice can significantly reduce CMI by improving allocation and utilization of attentional resources for both balance control and executive cognitive functioning; thus resulting in better performance under DT conditions.