Dual-task Walking Performance Research Articles

Associations between dual-task walking and cognitive impairment in people attending a cognitive diagnostic clinic.

Dual-task walking performance is an early marker of dementia. However, there is uncertainty about which measure of the dual-task test is a better marker. The objective of this study was to determine which dual-task measure best differentiates between normal cognition, mild cognitive impairment (MCI) and dementia. Participants (n = 116) were aged ≥60 years attending a cognitive clinic in Melbourne, Australia. Single- and dual-task gait speed were obtained using a 16 metre distance and stopwatch. The cognitive task involved reciting alternate letters of the alphabet sitting and walking. Dual-task interference in gait and cognition was calculated as: single-task-dual-task/single task × 100 and summed to obtain total interference. Multiple linear regression was used to determine differences in single and dual-task measures between those with no cognitive impairment (n = 11), MCI (n = 54) and dementia (n = 51). The mean age of the sample was 76.9 (SD 6.4) years and 48.3% (n = 56) were female. Compared to those with dementia: (a) those with MCI had a higher dual-task letter rate and lower cognitive and total interference (all indicate better performance) (p < .05) and (b) those with no cognitive impairment had a higher single- and dual-task letter rate (both indicate better performance) (p < .05). There were no differences between those with no cognitive impairment and those with MCI (all p > .05). In a cognitive clinic, measurement during dual-task walking differentiated those with dementia from those with MCI or no cognitive impairment. However, differences appear to be driven by performance on the cognitive, rather than the gait task.

Reliability and construct validity of three self-report questionnaires assessing dual-task difficulties in people with multiple sclerosis: an international study

ObjectiveTo evaluate the reliability and validity of the Dual-Tasking Questionnaire (DTQ), Dual-Task Screening-List (DTSL), and Dual-Task-Impact on Daily-life Activities Questionnaire (DIDA-Q). DesignMulti-center, cross-sectional study SettingPwMS were recruited from seven MS centers across six countries (Belgium, Chile, Italy, Israel, Spain, and Turkey). ParticipantsA total of 356 pwMS (mean age 47.5±11.5, EDSS 3.79±1.83) were enrolled. InterventionsNot applicable Main Outcome MeasuresThe reliability (internal consistency, test-retest, and measurement error) and construct validity (structural and convergent) were assessed. ResultsThe DTQ, DTSL, and DIDA-Q demonstrated excellent test-retest reliability [Intraclass correlation coefficients (95% CI): 0.84 (0.80-0.87) to 0.90 (0.87-0.92)] and internal consistency (Cronbach's α: 0.86 to 0.96). As hypothesized, the three questionnaires showed a strong correlation with each other, moderate-to-strong correlations with other self-report questionnaires (perceived walking difficulties, fatigue, and fear of falling), and low-to-moderate correlations with cognitive information processing speed, manual dexterity, and dual-task walking performance (walking with word list generation task), showing convergent validity. The DIDA-Q exhibited systematically superior properties. These results were also verified in subsets from six different countries. In the structural validity analysis, all questionnaires displayed two main factors, allocated as ‘motor-driven’ and ‘cognitive-driven’ subscales. ConclusionsThe DTQ, DTSL, and DIDA-Q have good-to-excellent measurement properties, with the highest properties observed in DIDA-Q. The use of these self-reported questionnaires can be used in research and clinical practice to assess the impact of dual-task difficulties on the daily life of ambulatory pwMS.

The contribution of cognitive reserve in explaining the dual-task walking performance in iNPH patients: comparison with other cognitive, functional, and socio-demographic variables

BackgroundIdiopathic normal pressure hydrocephalus (iNPH) is a prevalent neurological disorder, but its diagnosis remains challenging. Dual-task (DT) walking performance is a reliable indicator of iNPH but less is known about the role of cognitive reserve (CR) in predicting DT walking performance.AimsThe objective of this study was to evaluate the contribution of CR on DT walking in healthy controls (HC) and in iNPH patients (iNPH-P).Methods68 iNPH-P (77.2 +/- 6.7 years old) and 28 HC (74.5 +/- 5.7 years old) were evaluated on their single-task walking (Vsimple) and on 4 DT walking (walking and counting or counting backwards, naming animals, naming words beginning with the letter P) (Vcount, VcountB, Vanimals and Vletter respectively). The contribution of CR on the different DT walking speeds was compared between HC and iNPH-P. In iNPH-P, the contribution of CR on the walking speeds was compared with regard to other cognitive, functional, and socio-demographic variables.ResultsSimple linear regression demonstrated a moderate influence of CR on single and DT walking speed in iNPH-P (β > 0.3, p < .001) but not in HC where the relation was not significant. In iNPH-P, results showed that CR played a major role in explaining each of the single and DT walking speeds with NPH-scale.ConclusionAs CR could be improved through the life cycle, these results support the idea of developing and supporting physical activity programs that will enrich social, physical, and cognitive resources to protect against age-related functional decline, especially in iNPH-P patients where the age-related deficits are greater.

Disability Moderates Dual Task Walking Performance and Neural Efficiency in Older Adults With Multiple Sclerosis.

Mobility and cognitive impairment are prevalent and co-occurring in older adults with multiple sclerosis (OAMS), yet there is limited research concerning the role of disability status in the cognitive control of gait among OAMS. We investigated the levels of prefrontal cortex (PFC) activation, using oxygenated hemoglobin (HbO2), during cognitively-demanding tasks in OAMS with lower and higher disability using functional near-infrared spectroscopy (fNIRS) to: (1) identify PFC activation differences in single task walk and cognitively-demanding tasks in OAMS with different levels of disability; and (2) evaluate if disability may moderate practice-related changes in neural efficiency in OAMS. We gathered data from OAMS with lower (n = 51, age = 65 ± 4 years) or higher disability (n = 48, age = 65 ± 5 years), using a cutoff of 3 or more, in the Patient Determined Disease Steps, for higher disability, under 3 different conditions (single-task walk, Single-Task-Alpha, and Dual-Task-Walk [DTW]) administered over 3 counterbalanced, repeated trials. OAMS who had a lower disability level exhibited decreased PFC activation levels during Single-Task-Walk (STW) and larger increases in PFC activation levels, when going from STW to a cognitively-demanding task, such as a DTW, than those with higher disability. OAMS with a lower disability level exhibited greater declines in PFC activation levels with additional within session practice than those with a higher disability level. These findings suggest that disability moderates brain adaptability to cognitively-demanding tasks and demonstrate the potential for fNIRS-derived outcome measures to complement neurorehabilitation outcomes.

Neural Oscillations and Functional Significances for Prioritizing Dual-Task Walking in Parkinson's Disease.

Task prioritization involves allocating brain resources in a dual-task scenario, but the mechanistic details of how prioritization strategies affect dual-task walking performance for Parkinson's disease (PD) are little understood. We investigated the performance benefits and corresponding neural signatures for people with PD during dual-task walking, using gait-prioritization (GP) and manual-prioritization (MP) strategies. Participants (N = 34) were asked to hold two inter-locking rings while walking and to prioritize either taking big steps (GP strategy) or separating the two rings (MP strategy). Gait parameters and ring-touch time were measured, and scalp electroencephalograph was performed. Compared with the MP strategy, the GP strategy yielded faster walking speed and longer step length, whereas ring-touch time did not significantly differ between the two strategies. The MP strategy led to higher alpha (8-12 Hz) power in the posterior cortex and beta (13-35 Hz) power in the left frontal-temporal area, but the GP strategy was associated with stronger network connectivity in the beta band. Changes in walking speed and step length because of prioritization negatively correlated with changes in alpha power. Prioritization-related changes in ring-touch time correlated negatively with changes in beta power but positively with changes in beta network connectivity. A GP strategy in dual-task walking for PD can enhance walking speed and step length without compromising performance in a secondary manual task. This strategy augments attentional focus and facilitates compensatory reinforcement of inter-regional information exchange.

Brain control of dual-task walking can be improved in aging and neurological disease.

The peak prevalence of multiple sclerosis has shifted into older age groups, but co-occurring and possibly synergistic motoric and cognitive declines in this patient population are poorly understood. Dual-task-walking performance, subserved by the prefrontal cortex, and compromised in multiple sclerosis and aging, predicts health outcomes. Whether acute practice can improve dual-task walking performance and prefrontal cortex hemodynamic response efficiency in multiple sclerosis has not been reported. To address this gap in the literature, the current study examined task- and practice-related effects on dual-task-walking and associated brain activation in older adults with multiple sclerosis and controls. Multiple sclerosis (n = 94, mean age = 64.76 ± 4.19years) and control (n = 104, mean age = 68.18 ± 7.01years) participants were tested under three experimental conditions (dual-task-walk, single-task-walk, and single-task-alpha) administered over three repeated counterbalanced trials. Functional near-infrared-spectroscopy was used to evaluate task- and practice-related changes in prefrontal cortex oxygenated hemoglobin. Gait and cognitive performances declined, and prefrontal cortex oxygenated hemoglobin was higher in dual compared to both single task conditions in both groups. Gait and cognitive performances improved over trials in both groups. There were greater declines over trials in oxygenated hemoglobin in dual-task-walk compared to single-task-walk in both groups. Among controls, but not multiple sclerosis participants, declines over trials in oxygenated hemoglobin were greater in dual-task-walk compared to single-task-alpha. Dual-task walking and associated prefrontal cortex activation efficiency improved during a single session, but improvement in neural resource utilization, although significant, was attenuated in multiple sclerosis participants. These findings suggest encouraging brain adaptability in aging and neurological disease.

Cortical thickness moderates intraindividual variability in prefrontal cortex activation patterns of older adults during walking.

Increased intraindividual variability (IIV) in behavioral and cognitive performance is a risk factor for adverse outcomes but research concerning hemodynamic signal IIV is limited. Cortical thinning occurs during aging and is associated with cognitive decline. Dual-task walking (DTW) performance in older adults has been related to cognition and neural integrity. We examined the hypothesis that reduced cortical thickness would be associated with greater increases in IIV in prefrontal cortex oxygenated hemoglobin (HbO2) from single tasks to DTW in healthy older adults while adjusting for behavioral performance. Participants were 55 healthy community-dwelling older adults (mean age = 74.84, standard deviation (SD) = 4.97). Structural MRI was used to quantify cortical thickness. Functional near-infrared spectroscopy (fNIRS) was used to assess changes in prefrontal cortex HbO2 during walking. HbO2 IIV was operationalized as the SD of HbO2 observations assessed during the first 30 seconds of each task. Linear mixed models were used to examine the moderation effect of cortical thickness throughout the cortex on HbO2 IIV across task conditions. Analyses revealed that thinner cortex in several regions was associated with greater increases in HbO2 IIV from the single tasks to DTW (ps < .02). Consistent with neural inefficiency, reduced cortical thickness in the PFC and throughout the cerebral cortex was associated with increases in HbO2 IIV from the single tasks to DTW without behavioral benefit. Reduced cortical thickness and greater IIV of prefrontal cortex HbO2 during DTW may be further investigated as risk factors for developing mobility impairments in aging.

The impact of music making on neural efficiency & dual-task walking performance in healthy older adults

ABSTRACT Music making is linked to improved cognition and related neuroanatomical changes in children and adults; however, this has been relatively under-studied in aging. The purpose of this study was to assess neural, cognitive, and physical correlates of music making in aging using a dual-task walking (DTW) paradigm. Study participants (N = 415) were healthy adults aged 65 years or older, including musicians (n = 70) who were identified by current weekly engagement in musical activity. A DTW paradigm consisting of single- and dual-task conditions, as well as portable neuroimaging (functional near-infrared spectroscopy), was administered. Outcome measures included neural activation in the prefrontal cortex assessed across task conditions by recording changes in oxygenated hemoglobin, cognitive performance, and gait velocity. Linear mixed effects models examined the impact of music making on outcome measures in addition to moderating their change between task conditions. Across participants (53.3% women; 76 ± 6.55 years), neural activation increased from single- to dual-task conditions (p < 0.001); however, musicians demonstrated attenuated activation between a single cognitive interference task and dual-task walking (p = 0.014). Musicians also displayed significantly smaller decline in behavioral performance (p < 0.001) from single- to dual-task conditions and faster gait overall (p = 0.014). Given evidence of lower prefrontal cortex activation in the context of similar or improved behavioral performance, results indicate the presence of enhanced neural efficiency in older adult musicians. Furthermore, improved dual-task performance in older adult musicians was observed. Results have important clinical implications for healthy aging, as executive functioning plays an essential role in maintaining functional ability in older adulthood.

The Executive-Function-Related Cognitive–Motor Dual Task Walking Performance and Task Prioritizing Effect on People with Parkinson’s Disease

To safely walk in a community environment requires dual cognitive-walking ambulation ability for people with Parkinson's disease (PD). A past study showed inconsistent results on cognitive-walking performance for PD patients, possibly due to the various cognitive tasks used and task priority assignment. This study designed cognitive-walking tests that used executive-related cognitive tasks to evaluate patients with early-stage Parkinson's disease who did not have obvious cognitive deficits. The effect of assigning task prioritization was also evaluated. Sixteen individuals with PD (PD group) and 16 individuals without PD (control group) underwent single cognitive tests, single walking tests, dual walking tests, and prioritizing task tests. Three types of cognitive, spatial memory, Stroops, and calculation tasks were employed. The cognitive performance was evaluated by response time, accuracy, and speed-accuracy trade off composite score. The walking performance was evaluated by the temporal spatial gait characteristics and variation in gait. The results showed that the walking performance of the PD group was significantly worse than the control group in both single and dual walking conditions. The group difference in cognitive performance was shown in composite score under the dual calculation walking task but not under the single task. While assigning priority to walking, no group difference in walking was observed but the response accuracy rate of PD groups declined. This study concluded that the dual task walking test could sharpen the cognitive deficits for early-stage PD patients. The task priority assignment might not be recommended while testing gait deficits since it decreased the ability to discriminate group differences.

Effects of different dual task training on dual task walking and responding brain activation in older adults with mild cognitive impairment

The concurrent additional tasking impacts the walking performance, and such impact is even greater in individuals with mild cognitive impairment (MCI) than in healthy elders. However, effective training program to improve dual task walking ability for the people with MCI is not immediately provided. Therefore, this study aimed to determine the effects of cognitive and motor dual task walking training on dual task walking performance and the responding brain changes in older people with MCI. Thirty older adults with MCI were randomly allocated to receive 24 sessions of 45-min cognitive dual task training (CDTT, n = 9), motor dual task training (MDTT, n = 11), or conventional physical therapy (CPT, n = 10). Gait performance and brain activation during single and dual task walking, and cognitive function assessed by trail-making test (TMT-A, B) and digit span test were measured at pre-, post-test, and 1-month follow-up. Both CDTT and MDTT improved dual task walking with responding activation changes in specific brain areas. The improvements in motor dual task walking performance after both dual task trainings were significantly better than after CPT in the older adults with MCI. Both cognitive and motor dual task training were feasible and beneficial to improve dual task walking ability in older adults with MCI.Trial Registration: The trial was registered to Thai Clinical Trial Registry and the registration number is TCTR20180510002 (first registration date: 10/05/2018).

Multiarea Brain Activation and Gait Deterioration During a Cognitive and Motor Dual Task in Individuals With Parkinson Disease.

In people with Parkinson disease (PD), gait performance deteriorating during dual-task walking has been noted in previous studies. However, the effects of different types of dual tasks on gait performance and brain activation are still unknown. The purpose of this study was to investigate cognitive and motor dual-task walking performance on multiarea brain activity in individuals with PD. Twenty-eight participants with PD were recruited and performed single walking (SW), walking while performing a cognitive task (WCT), and walking while performing a motor task (WMT) at their self-selected speed. Gait performance including walking speed, stride length, stride time, swing cycle, temporal and spatial variability, and dual-task cost (DTC) was recorded. Brain activation of the prefrontal cortex (PFC), premotor cortex (PMC), and supplementary motor areas (SMA) were measured using functional near-infrared spectroscopy during walking. Walking performance deteriorated upon performing a secondary task, especially the cognitive task. Also, a higher and more sustained activation in the PMC and SMA during WCT, as compared with the WMT and SW, in the late phase of walking was found. During WMT, however, the SMA and PMC did not show increased activation compared with during SW. Moreover, gait performance was negatively correlated with PMC and SMA activity during different walking tasks. Individuals with mild to moderate PD demonstrated gait deterioration during dual-task walking, especially during WCT. The SMA and PMC were further activated in individuals with PD when performing cognitive dual-task walking.Supplemental Digital Content is Available in the Text.Video Abstract available for more insights from the authors (see the Video, Supplemental Digital Content 1, available at: http://links.lww.com/JNPT/A383 ).

Effects of a 6-Min Treadmill Walking Test on Dual-Task Gait Performance and Prefrontal Hemodynamics in People With Multiple Sclerosis.

Fatigue is one of the most limiting symptoms in people with multiple sclerosis (pwMS) and can be subdivided into trait and state fatigue. Activity-induced state fatigue describes the temporary decline in motor and/or cognitive performance (motor and cognitive performance fatigability, respectively) and/or the increase in the perception of fatigue (perceived fatigability) in response to motor or cognitive tasks. To the best of our knowledge, the effects of a 6-min walk test (6MWT), which was often used to assess motor performance fatigability in pwMS, on motor-cognitive dual-task performance (i.e., walking + arithmetic task) and prefrontal cortex (PFC) hemodynamics are not well-known. This is of importance, since daily activities are often performed as multitasks and a worse dual-task walking performance is associated with an increased risk of falling. Consequently, we investigated the effect of a fast 6MWT (comfort velocity + 15%) performed on a treadmill on motor-cognitive performance fatigability (spatio-temporal gait parameters/accuracy during the arithmetic task) and perceived fatigability measures (rating of perceived exhaustion; RPE) as well as PFC hemodynamics recorded during dual-task walking in pwMS and healthy controls (HCs). Twenty pwMS (48.3 ± 9.0 years; 13 females/7 males; expanded disability status scale 2.7 ± 1.0, first diagnosis 13.8 ± 8.8 years) and 24 HC with similar age and sex (48.6 ± 7.9 years; 17 females/7 males) were included. Only cognitive performance fatigability (increased error rate) during dual-task walking was found after the fast 6MWT on the treadmill in pwMS. However, the changes in gait parameters did not indicate motor performance fatigability, although both the groups reported perceived fatigability (increased RPE) after the fast 6MWT. Moreover, no change in the PFC activation was detected in both groups. Our results suggest that the intensity and/or duration of the fast 6MWT was not sufficient to induce motor performance fatigability in pwMS. These factors should be addressed by future studies on this topic, which should also consider further parameters, e.g., muscular oxygenation and/or myoelectrical activity, to verify that exercise intensity and/or duration was appropriate to induce motor performance fatigability in pwMS.Clinical Trial RegisterDRKS00021057.

Effects of fundamental movement skills based dual-task and dance training on single- and dual-task walking performance in older women with dementia

ObjectiveThe purpose of this study was to compare the effects of fundamental movement skills (FMS)-based dual-task training and dance training on spatio-temporal characteristics of gait performance under single- and dual-task walking conditions among older women with dementia. MethodThirty-eight elderly females with dementia were randomly assigned to one of two groups: (1) dual-task intervention (DTI, age: 73 ± 6.5 years) or (2) Iranian dance intervention (IDI, age: 72.52 ± 6.01 years). Both groups participated in a 10-week intervention program (3 sessions per week, each lasting 50 min). Gait performance parameters (gait speed, cadence, and stride length) and dual-task costs (DTC) were examined using a gait analysis system. The participants completed three walking trials under two conditions: single- and dual-task. The video data was analyzed using motion analysis software (Frame-DIAS II, DKH, DKH Inc., Tokyo, Japan). ResultsThe results showed that both groups significantly improved in terms of all gait variables, and DTC decreased (p < .001) from pre- to post-test for both conditions. However, the main effects for the group and the group-by-time interactions were not significantly different between the two groups (p > .05). ConclusionThese findings showed that DTI and IDI effectively improved gait performance following a 10-week intervention for older women with dementia. Therefore, it is suggested that either training program could decrease DTC and increase gait speed, stride length, and cadence among older females with dementia.

Comparing different montages of transcranial direct current stimulation on dual-task walking and cortical activity in chronic stroke: double-blinded randomized controlled trial

BackgroundTranscranial direct current stimulation (tDCS) is a noninvasive brain stimulation to modulate cortical activity for improving motor function. However, the different tDCS applications for modulating cortical activity and dual task gait performance in chronic stroke have not yet been investigated. This study investigated the effects of different tDCS applications on dual task gait performance and contralesional M1 activation in chronic stroke.MethodsForty-eight participants were randomized to anodal, bilateral, cathodal, and sham tDCS groups. Each group received 20 min of tDCS stimulation, except the sham group. Gait performance was measured by GaitRite system during cognitive dual task (CDT) walking, motor dual task (MDT) walking, and single walking (SW). Contralesional M1 activity of unaffected tibialis anterior (TA) was measured using transcranial magnetic stimulation (TMS). Intragroup difference was analyzed by Wilconxon sign ranks test with Bonferroni correction, and Kruskal–Wallis one-way analysis of variance by ranks was used for intergroup comparisons, followed by post-hoc Mann–Whitney U tests with Bonferroni correction.ResultsThe bilateral tDCS (p = 0.017) and cathodal tDCS (p = 0.010) improved the CDT walking speed more than sham group. The bilateral tDCS (p = 0.048) and cathodal tDCS (p = 0.048) also improved the MDT walking speed more than sham group. Furthermore, bilateral tDCS (p = 0.012) and cathodal tDCS (p = 0.040) increased the silent period (SP) more than the anodal and sham group. Thus, one-session of bilateral and cathodal tDCS improved dual task walking performance paralleled with increasing contralesional corticomotor inhibition in chronic stroke.ConclusionsOur results indicate that one-session of bilateral and cathodal tDCS increased contralesional corticomotor inhibition and improved dual task gait performance in chronic stroke.Trial registrationThai Clinical Trials Registry (TCTR20180116001). Registered prospectively on 16th Jan, 2018 at http://www.thaiclinicaltrials.org.

Neural correlates of dual-task walking in people with central neurological disorders: a systematic review.

People with central neurological disorders experience difficulties with dual-task walking due to disease-related impairments. The objective of this review was to provide a comprehensive examination of the neural correlates (structural/functional brain changes) of dual-task walking in people with Parkinson's disease (PD), multiple sclerosis (MS), stroke, and Alzheimer's disease (AD). A systematic review of the literature was conducted, following PRISMA guidelines, on Medline, Embase, and Scopus. Included studies examined the relationship between structural and functional brain imaging and dual-task walking performance in people with PD, MS, stroke, and AD. Articles that met the inclusion criteria had baseline characteristics, study design, and behavioral and brain outcomes extracted. Twenty-three studies were included in this review. Most structural imaging studies (75%) found an association between decreased brain integrity and poor dual-task performance. Specific brain regions that showed this association include the striatum regions and hippocampus in PD and supplementary motor area in MS. Functional imaging studies reported an association between increased prefrontal activity and maintained (compensatory recruitment) or decreased dual-task walking performance in PD and stroke. A subset (n = 2) of the stroke papers found no significant correlations. Increased supplementary motor area activity was associated with decreased performance in MS and stroke. No studies on AD were identified. In people with PD, MS, and stroke, several neural correlates of dual-task walking have been identified, however, the direction of the association between neural and performance outcomes varied across the studies. The type of cognitive task used and presentation modality (e.g., visual) may have contributed to these mixed findings.

Effects of Age on Dual Task Walking Performance as Measured Using a Smartphone Application in Middle-Aged Adults

After the age of 65, one’s ability to walk while performing an additional cognitive task (i.e., dual-tasking) is predictive of both future falls and cognitive decline. However, while it is well-known that older adults exhibit diminished dual-task performance, the time course of age-related dual-task decline has not been established. We thus conducted an analysis of data collected within the ongoing Barcelona Brain Health Initiative, a prospective population-based study characterizing the determinants of brain health maintenance in middle-aged adults. Cognitively-unimpaired participants (n=655) aged 40-65 years without neuro-psychiatric disease completed laboratory-based trials of walking normally (single-task) and walking while performing a verbalized serial subtraction task (dual-task). A smartphone-based gait assessment application was used to capture data and derive both the mean stride time (ST) and stride time variability (STV, defined as the coefficient of variation about the mean stride time) of each trial. The dual-task costs (DTC) to each gait metric were obtained by calculating the percent change from single- to dual-task conditions. We categorized participants into five groups according to age (e.g. Group 1: 40-45 years; Group 5: 60-65 years). Age group did not have an effect on single-task gait outcomes (p>0.51). However, the oldest age group, as compared to each of the other groups, exhibited greater DTC to both ST and STV (p<0.03). These results indicate that dual-task walking performance in particular may begin to diminish in late middle age even in the absence of detectable cognitive issues, DTC may offer a sensitive metric to age-related change in cognitive function.

Associations between clinical characteristics and dual task performance in Multiple Sclerosis depend on the cognitive and motor dual tasks used.

Background: In persons with Multiple Sclerosis (pwMS) performing a simultaneous cognitive task while walking often results in slower gait. Clinical characteristics associated with reduced dual task (DT) performance are not yet entirely clear. This multi-centre study aimed to determine the relationship between clinical and demographical characteristics with dual task (DT) walking performance in pwMS during multiple DT conditions.Methods: Nine DT conditions were analysed, consisting of combinations of three types of cognitive (‘digit span’, ‘subtraction’, ‘vigilance’) and three types of walking (‘walk’, ‘walk with cup’, ‘walk over obstacles’) conditions. Primary outcomes were DT gait speed (m/s) and motor DT cost of gait speed (DTCmotor, %). Secondary outcomes were clinical tests of physical and cognitive functioning and patient-reported and demographical outcomes. Firstly, univariate analyses and, subsequently, multivariate analyses with backward modelling, were conducted for each type of walking DT condition separately. Cognitive DT conditions were included in the models as main and as interaction effect with the secondary outcomes.Results: Analysis were performed in 81 pwMS (EDSS 3.3 ± 1.0). In the final models of DTCmotor, the significant main effects were in ‘walk’ DT-conditions the Symbol Digit Modalities Test (SDMT), in ‘cup’ conditions the SDMT and Dynamic Gait Index and in ‘obstacles’ conditions age. For DT gait speed, main effects were found for the 2-Minute Walking Test (2MWT) and the Multiple Sclerosis Walking Scale for all walking conditions. Additionally, interactions between cognitive DT-conditions and SDMT, age and 2MWT were found.Conclusion: Clinical characteristics related to DT walking performance differed according to cognitive-motor DT-condition used. Still, in general, pwMS with a better mobility demonstrated higher DT gait speed, while a faster information processing speed was related to a lower DTCmotor.

Can dual-task paradigms predict Falls better than single task? – A systematic literature review

With about one third of adults aged 65 years and older being reported worldwide to fall each year, and an even higher prevalence with advancing age, aged-related falls and the associated disabilities and mortality are a major public health concern. In this context, identification of fall risk in healthy older adults is a key component of fall prevention. Since dual-task outcomes rely on the interaction between cognition and motor control, some studies have demonstrated the role of dual-task walking performance or costs in predicting future fallers. However, based on previous reviews on the topic, (1) discriminative and (2) predictive powers of dual tasks involving gait and a concurrent task are still a matter of debate, as is (3) their superiority over single tasks in terms of fall-risk prediction. Moreover, less attention has been paid to dual tasks involving postural control and transfers (such as gait initiation and turns) as motor tasks. In the present paper, we therefore systematically reviewed recent literature over the last 7 years in order to answer the three above mentioned questions regarding the future of lab-based dual tasks (involving posture, gait initiation, gait and turning) as easily applicable tests for identifying healthy older adult fallers. Despite great heterogeneity among included studies, we emphasized, among other things, the promising added value of dual tasks including turns and other transfers, such as in the Timed Up and Go test, for prediction of falls. Further investigation of these is thus warranted.

Cognitive Frailty Among Elderly Chinese Patients With Cerebral Small Vessel Disease: A Structural MRI Study

Cognitive frailty (CF) is gaining an increasing amount of attention in geriatric research. CF refers to the co-occurrence of physical frailty and cognitive impairment in people without dementia. Neuroimaging of elderly people has revealed the presence of numerous white matter lesions, which is a typical biomarker of cerebral small vessel disease (SVD) on magnetic resonance images. The aim of the present study was to estimate the prevalence of CF in elderly Chinese patients with SVD. One hundred and thirty elderly patients with SVD were recruited for this cross-sectional observational study. Participants who met three to five of the Fried criteria of the physical frailty (PF) phenotype (shrinking, weakness, slowness, self-reported exhaustion, or low physical activity) were classified as having PF. Then, individuals with PF were defined as having CF if mild cognitive impairment was discovered by the Mini-Mental State Examination. Lastly, a series of cognitive function tests and the dual-task walking paradigm were examined. Based on the CF diagnostic criteria, the frequency of CF was 23.08% among elderly Chinese patients with SVD. Furthermore, CF-positive patients had a more significant SVD burden, based on magnetic resonance imaging findings. Logistic regression analysis, which was adjusted for age, sex, education, and comorbidities, showed that CF was negatively correlated with the dual-task walking speed in elderly people with SVD. Thus, SVD burden might be an indicator of CF phenotype. In elderly patients with SVD, CF was associated with dual task walking performance.

Distinct Effects of Motor Training on Resting-State Functional Networks of the Brain in Parkinson’s Disease

Background. Nigrostriatal dopaminergic loss is a hallmark of Parkinson’s disease (PD) pathophysiology, leading to motor Parkinsonism. Different intervention protocols have shown that motor and cognitive functions improvement in PD occur via the modulation of distinct motor and cognitive pathways. Objective. To investigate the effects of two motor training programs on the brains’ functional networks in PD patients. Methods. Thirty-seven PD patients were prospectively studied. All enrolled patients underwent either treadmill training (TT) (n = 19) or treadmill with virtual reality (TT + VR) (n = 18) for 6 weeks. Magnetic resonance imaging (MRI) scans (3 T) acquiring 3-dimensional T1-weighted and resting-state functional MRI (rs-fMRI) data sets were performed at baseline and after 6 weeks. Independent component analysis (ICA) was conducted, and functional connectivity (FC) changes within large-scale functional brain networks were examined. Results. In both groups, significant post-training FC decrease in striatal, limbic, and parietal regions within the basal ganglia network, executive control network, and frontal-striatal network, and significant FC increase in the caudate, and cingulate within the sensorimotor network (SMN) were observed. Moreover, a significant time × group interaction was detected where TT + VR training had greater effects on FC levels in the supplementary motor area (SMA) and right precentral gyrus within the SMN, and in the right middle frontal gyrus (MFG) within the cerebellar network. These FC alterations were associated with improved usual and dual-task walking performance. Conclusions. These results suggest that TT with-and-without the addition of a VR component affects distinct neural pathways, highlighting the potential for beneficial neural plasticity in PD. Such distinctive task-specific pathways may foster the facilitation of interventions tailored to the individual needs of PD patients. Registered at Clinicaltrials.gov number: NCT01732653.