Cerebral Microbleeds Were Related With Poor Cognitive Performances on the Dual Task Condition in Older Adults

Background: The dual task (DT) was commonly used to assess the risk of falls in older adults and patients with neurological disorders. However, the performance on DT conditions has not been well investigated in patients with cerebral microbleed (CMB). This study is aimed to compare the performance in DT tests between older adults with and without CMB, and to explore the association between CMB and cognitive performances of DT.Methods: This is a cross-sectional study. A total of 211 old adults participated, involving 68 CMB patients. The task protocol involved two global cognition tests, two single cognitive tests (serial 7 subtraction and semantic fluency), two single motor tasks [8-m walking and timed up and go test (TUG)], and three DT tests [walking and serial subtraction (WSS), walking and semantic fluency (WSF), and TUG and serial subtraction (TUGSS)]. The time taken to complete each task and the number of correct responses were recorded. For each DT condition, the correct response rate (CRR) and the dual-task effect (DTE) for the correct number were calculated.Results: Compared with subjects without CMB, CMB patients had worse cognitive performances on DT condition in CRR of WSS (p = 0.003), WSF (p = 0.030) and TUGSS (p = 0.006), and DTE of WSS (p = 0.017). Binary logistic regression analysis showed that the presence of CMB was an independent risk factor for the impairment group for CRR of TUGSS (OR, 2.54; 95% CI, 1.11–5.82; p = 0.027) with the adjustment for confounders, rather than CRR of WSS and WSF, or DTE of WSS. Multiple linear regression analysis showed that CRR of TUGSS decreased with the increase of CMB number grades (β, −0.144; 95% CI, −0.027, −0.002; p = 0.028).Conclusion: The present study indicated that CMBs were closely associated with poor cognitive performances on DT in the elderly. Strongest effect size was seen for CRR of TUGSS, where performance deficits increased in proportion to the degree of CMB burden.

The Effect of Cognitive Task on Postural Control Dynamic Regularity of Athletes With Chronic Ankle Instability When Standing on an Unstable Surface

Background and Objectives: Postural control disorder is a common complication in patients with Chronic Ankle Instability (CAI). The present study aimed to investigate the effect of dual cognitive task on postural control behavior with regard to the Center of Pressure (CoP) signal regularity while standing on an unstable surface in athletes with CAI. Methods: In the present study, 58 men participated in two groups of healthy and patients with CAI. The CoP signal was examined in 4 different unstable states on the wobble board located at the center of the force plate. The regularity of the signals recorded from the force plate was investigated using sample entropy in two directions: anterior-posterior and medial-lateral. Results: In both groups, there was a significant difference in CoP’s sample entropy signal when performing a cognitive task with a postural task (P<0.001). There was a significant difference between the two groups in the cognitive task and the single task in the anteroposterior direction while standing on two legs. Conclusion: During dual tasks, the patients with CAI have a more dynamic regularity in the CoP signal than their normal counterparts. In the dual-task condition, more irregularities are observed in the CoP signal of healthy individuals. In unstable conditions, patients with CAI decrease the adaptability of postural control behavior with increasing CoP signal regularity.

2BALANCE: Test-retest reliability of a cognitive-motor dual-task protocol

PURPOSE: Aside from typical symptoms such as dizziness and vertigo, persons with vestibular disorders often have cognitive and motor problems. These symptoms have been assessed in single-task condition. However, dual-tasks assessing cognitive-motor interference might be an added value as they reflect daily life situations better. Therefore, the 2BALANCE protocol was developed. In the current study, the test-retest reliability of this protocol was assessed. METHODS: The 2BALANCE protocol was performed twice in 20 healthy young adults with an in-between test interval of two weeks. Two motor tasks and five different cognitive tasks were performed in single and dual-task condition. Intraclass correlation coefficients (ICC), the standard error of measurement, and the minimal detectable difference were calculated. RESULTS: All cognitive tasks, with the exception of the mental rotation task, had favorable reliability results (0.26≤ICC≤0.91). The dynamic motor task indicated overall substantial reliability values in all conditions (0.67≤ICC≤0.98). Similar results were found for the static motor task during dual-tasking (0.50≤ICC≤0.92), but were slightly lower in single-task condition (–0.26≤ICC≤0.75). CONCLUSIONS: The 2BALANCE protocol was overall consistent across trials. However, the mental rotation task showed lowest reliability values.

Obstacle Avoidance and Dual-Tasking During Reaching While Standing in Patients With Mild Chronic Stroke

Background. Poststroke individuals use their paretic arms less often than expected in daily life situations, even when motor recovery is scored highly in clinical tests. Real-world environments are often unpredictable and require the ability to multitask and make decisions about rapid and accurate arm movement adjustments. Objective. To identify whether and to what extent cognitive–motor deficits in well-recovered individuals with stroke affect the ability to rapidly adapt reaching movements in changing cognitive and environmental conditions. Methods. Thirteen individuals with mild stroke and 11 healthy controls performed an obstacle avoidance task in a virtual environment while standing. Subjects reached for a virtual juice bottle with their hemiparetic arm as quickly as possible under single- and dual-task conditions. In the single-task condition, a sliding glass door partially obstructed the reaching path of the paretic arm. A successful trial was counted when the subject touched the bottle without the hand colliding with the door. In the dual-task condition, subjects repeated the same task while performing an auditory–verbal working memory task. Results. Individuals with stroke had significantly lower success rates than controls in avoiding the moving door in single-task (stroke: 51.8 ± 21.2%, control: 70.6 ± 12.7%; P = .018) and dual-task conditions (stroke: 40.0 ± 27.6%, control: 65.3 ± 20.0%; P = .015). Endpoint speed was lower in stroke subjects for successful trials in both conditions. Obstacle avoidance deficits were exacerbated by increased cognitive demands in both groups. Individuals reporting greater confidence using their hemiparetic arm had higher success rates. Conclusion. Clinically well-recovered individuals with stroke may have persistent deficits performing a complex reaching task.

Are Static and Dynamic Postural Balance Assessments Two Sides of the Same Coin? A Cross-Sectional Study in the Older Adults

The aim of this study was to investigate if the combination of static and dynamic postural balance assessments gives more accurate indications on balance performance among healthy older adults. We also aimed at studying the effect of a dual-task condition on static and dynamic postural balance control. Fifty-seven healthy older adults (age = 73.2 ± 5.0 year, height = 1.66 ± 0.08 m, and body mass = 72.8 ± 13.8 kg) completed the study. Static and dynamic balance were assessed both in single-task and dual-task conditions through a force plate and an oscillating platform. The dominant handgrip strength was also measured with a dynamometer. Pearson’s correlation revealed non-statistically significant correlations between static and dynamic balance performance. The dual-task worsened the balance performance more in the dynamic (+147.8%) than in the static (+25.10%, +43.45%, and +72.93% for ellipse area, sway path, and AP oscillations, respectively) condition (p &lt; 0.001). A weak correlation was found between dynamic balance performance and handgrip strength both in the single (p &lt; 0.05; r = −0.264) and dual (p &lt; 0.05; r = −0.302) task condition. The absence of correlations between static and dynamic balance performance suggests including both static and dynamic balance tests in the assessment of postural balance alterations among older adults. Since cognitive-interference tasks exacerbated the degradation of the postural control performance, dual-task condition should also be considered in the postural balance assessment.

The Influence of Wobble Board on Spatial Learning and Navigation: Sex Differences in Learning Performance

In order to determine how postural control affects spatial memory performance, the present study looked at the interaction between postural control on a wobble board and performance in a concurrent spatial navigation task (virtual Morris water maze) in 68 participants. Participants in dual task condition navigated the virtual maze on a wobble board, while participants in single task condition navigated in the normal standing way. Postural sway errors on wobble board, path length and duration to find platform were measured during the experiment. The main effect of the condition showed that participants in the dual task condition took longer paths to find the hidden platform, and were slower compared to participants in the single task condition. In terms of sex differences, the results showed that male participants found the hidden platform faster and used shorter paths than females in both conditions.

Detection of Motor Dysfunction With Wearable Sensors in Patients With Idiopathic Rapid Eye Movement Disorder

Patients with idiopathic rapid eye movement sleep behavior disorder (iRBD) are at high risk for conversion to synucleinopathy and Parkinson disease (PD). This can potentially be monitored by measuring gait characteristics of iRBD patients, although quantitative data are scarce and previous studies have reported inconsistent findings. This study investigated subclinical gait changes in polysomnography-proven iRBD patients compared to healthy controls (HCs) during 3 different walking conditions using wearable motor sensors in order to determine whether gait changes can be detected in iRBD patients that could reflect early symptoms of movement disorder. A total 31 iRBD patients and 20 HCs were asked to walk in a 10-m corridor at their usual pace, their fastest pace, and a normal pace while performing an arithmetic operation (dual-task condition) for 1 min each while using a wearable gait analysis system. General gait measurements including stride length, stride velocity, stride time, gait length asymmetry, and gait variability did not differ between iRBD patients and HCs; however, the patients showed decreases in range of motion (P = 0.004) and peak angular velocity of the trunk (P = 0.001) that were significant in all 3 walking conditions. iRBD patients also had a longer step time before turning compared to HCs (P = 0.035), and the difference between groups remained significant after adjusting for age, sex, and height. The decreased trunk motion while walking and increased step time before turning observed in iRBD may be early manifestations of body rigidity and freezing of gait and are possible prodromal symptoms of PD.

The Effects of Transcranial Direct Current Stimulation on Dual-Task Interference Depend on the Dual-Task Content

Recently, some studies revealed that transcranial direct current stimulation (tDCS) reduces dual-task interference. Since there are countless combinations of dual-tasks, it remains unclear whether stable effects by tDCS can be observed on dual-task interference. An aim of the present study was to investigate whether the effects of tDCS on dual-task interference change depend on the dual-task content. We adopted two combinations of dual-tasks, i.e., a word task while performing a tandem task (word-tandem dual-task) and a classic Stroop task while performing a tandem task (Stroop-tandem dual-task). We expected that the Stroop task would recruit the dorsolateral prefrontal cortex (DLPFC) and require involvement of executive function to greater extent than the word task. Subsequently, we hypothesized that anodal tDCS over the DLPFC would improve executive function and result in more effective reduction of dual-task interference in the Stroop-tandem dual-task than in the word-tandem dual-task. Anodal or cathodal tDCS was applied over the DLPFC or the supplementary motor area using a constant current of 2.0 mA for 20 min. According to our results, dual-task interference and the task performances of each task under the single-task condition were not changed after applying any settings of tDCS. However, anodal tDCS over the left DLPFC significantly improved the word task performance immediately after tDCS under the dual-task condition. Our findings suggested that the effect of anodal tDCS over the left DLPFC varies on the task performance under the dual-task condition was changed depending on the dual-task content.

Effects of dual-task gait treadmill training on gait ability, dual-task interference, and fall efficacy in people with stroke: A Randomized Controlled Trial

Objective This study aimed to investigate the effects of dual-task gait training using a treadmill on gait ability, dual-task interference, and fall efficacy in people with stroke. Methods Patients with chronic stroke (N = 34) were recruited and randomly allocated to the experimental or control group. Both groups underwent gait training on a treadmill and a cognitive task. In the experimental group, gait training was conducted in conjunction with the cognitive task, whereas in the control group, the training and the cognitive task were conducted separately. Each intervention was provided for 60 minutes, twice a week, for a period of 6 weeks for both groups. The primary outcomes were as follows: gait parameters (speed, stride, variability, and cadence) under single-task and dual-task conditions, correct response rate (CRR) under single-task and dual-task conditions, and dual-task cost (DTC) in gait parameters and CRR. The secondary outcome was the fall efficacy scale. Results Dual-task gait training using a treadmill improved all gait parameters in the dual-task condition, speed, stride, and variability in the single-task condition, and CRR in both conditions. Difference between the groups was observed in speed, stride, and variability in the dual-task condition. Furthermore, dual-task gait training on a treadmill improved DTC in speed, variability, and cadence along with that in CRR, indicating true improvement of DTC, which led to significant improvement in DTC in speed and variability compared with single-task training. Conclusions Dual-task gait treadmill training was more effective in improving gait ability in dual-task training and DTI than single-task training involving gait and cognitive task separately in people with chronic stroke.

Neuroimaging, Behavioral, and Gait Correlates of Fall Profile in Older Adults

Prior research has suggested that measurements of brain functioning and performance on dual tasks (tasks which require simultaneous performance) are promising candidate predictors of fall risk among older adults. However, no prior study has investigated whether brain function measurements during dual task performance could improve prediction of fall risks and whether the type of subtasks used in the dual task paradigm affects the strength of the association between fall characteristics and dual task performance. In this study, 31 cognitively normal, community-dwelling older adults provided a self-reported fall profile (number of falls and fear of falling), completed a gait dual task (spell a word backward while walking on a GaitRite mat), and completed a supine dual task (rhythmic finger tapping with one hand while completing the AX continuous performance task (AX-CPT) with the other hand) during functional magnetic resonance imaging (fMRI). Gait performance, AX-CPT reaction time and accuracy, finger tapping cadence, and brain functioning in finger-tapping-related and AX-CPT-related brain regions all showed declines in the dual task condition compared to the single task condition. Dual-task gait, AX-CPT and finger tapping performance, and brain functioning were all independent predictors of fall profile. No particular measurement domain stood out as being the most strongly associated measure with fall variables. Fall characteristics are determined by multiple factors; brain functioning, motor task, and cognitive task performance in challenging dual-task conditions all contribute to the risk of falling.