Actual and Imagined Music-Cued Gait Training in People with Multiple Sclerosis: A Double-Blind Randomized Parallel Multicenter Trial

BACKGROUND

Actual and imagined cued gait trainings have not been compared in people with multiple sclerosis (MS).

OBJECTIVE

To analyze the effects of cued motor imagery (CMI), cued gait training (CGT), and combined CMI and cued gait training (CMI-CGT) on motor, cognitive, and emotional functioning, and health-related quality of life in people with MS.

METHODS

In this double-blind randomized parallel-group multicenter trial, people with MS were randomized (1:1:1) to CMI, CMI-CGT, or CGT for 30 minutes, 4×/week for 4 weeks. Patients practiced at home, using recorded instructions, and supported by ≥6 phone calls. Data were collected at weeks 0, 4, and 13. Co-primary outcomes were walking speed and distance, analyzed by intention-to-treat. Secondary outcomes were global cognitive impairment, anxiety, depression, suicidality, fatigue, HRQoL, motor imagery ability, music-induced motivation, pleasure and arousal, self-efficacy, and cognitive function. Adverse events and falls were continuously monitored.

RESULTS

Of 1559 screened patients, 132 were randomized: 44 to CMI, 44 to CMI-CGT, and 44 to CGT. None of the interventions demonstrated superiority in influencing walking speed or distance, with negligible effects on walking speed (η2 = 0.019) and distance (η2 = 0.005) observed in the between-group comparison. Improvements in walking speed and walking distance over time corresponded to large effects for CMI, CMI-CGT, and CGT (η2 = 0.348 and η2 = 0.454 respectively). No severe study-related adverse events were reported.

CONCLUSIONS

CMI-GT did not lead to improved walking speed and distance compared with CMI and CGT alone in people with MS. Lack of a true control group represents a study limitation.

TRIAL REGISTRATION

German Clinical Trials Register, DRKS00023978.

Motor imagery ability of children with duchenne muscular dystrophy: Reliability and validity of kinesthetic and Visual Imagery Questionnaire-10, and its association with cognitive status

PURPOSE

To investigate validity and reliability of the Kinesthetic and Visual Imagery Questionnaire-10 (KVIQ-10) in children with Duchenne Muscular Dystrophy (DMD), to compare the motor imagery (MI) ability with age-matched controls, and to examine the relationship between MI ability and cognitive status.

METHODS

The research involved 38 children who were diagnosed with DMD, as well as 20 healthy controls aged between 7 and 18 years. The KVIQ-10 was assessed for its test-retest reliability, internal consistency, construct and concurrent validity. The Motor Imagery Questionnaire for Children (MIQ-C) was selected as the gold standard test for concurrent validity. Cognitive function was assessed using the Modified Mini Mental Test (MMMT) and Montreal Cognitive Assessment (MoCA).

RESULTS

KVIQ-10 showed excellent test-retest reliability (ICC>0.90) and high internal consistency (Cronbach's alpha>0.70). A moderate-to-strong association was found between KVIQ-10 and MIQ-C subscales (p < 0.001). KVIQ-10 and MIQ-C subscores were statistically lower in the DMD group (p ≤ 0.05). A correlation was found between MoCA and KVIQ-10 in children with DMD (p ≤ 0.05).

CONCLUSIONS

The KVIQ-10 is a reliable and valid measure to assess the MI ability of children with DMD whose imagery ability was determined to be impaired.

CLINICAL TRIAL REGISTRATION NUMBER AND URL

NCT05559710 (https://classic.

CLINICALTRIALS

gov/ct2/show/NCT05559710?term=NCT05559710&draw=2&rank=1).

Motor imagery ability in baseball players with throwing yips

The motor imagery ability is closely related to an individual's motor performance in sports. However, whether motor imagery ability is diminished in athletes with yips, in whom motor performance is impaired, is unclear. Therefore, this cross-sectional study aimed to determine whether general motor imagery ability or vividness of motor imagery specific to throwing motion is impaired in baseball players with throwing yips. The study enrolled 114 college baseball players. They were classified into three groups: 33 players in the yips group, 26 in the recovered group (previously had yips symptoms but had resolved them), and 55 in the control group. They answered the revised version of the vividness of movement imagery questionnaire (VMIQ-2), which assesses general motor imagery ability. Furthermore, they completed a questionnaire that assesses both positive and negative motor imagery vividness specific to baseball throwing. In the former, they responded to their ability to vividly imagine accurately throwing a controlled ball, whereas in the latter, they responded to the vividness of their experience of negative motor imagery associated with baseball throwing, specifically the image of a wild throw. No significant difference in the VMIQ-2 was found among the three groups. While no significant difference in the vividness of positive motor imagery for ball throwing was found in either first-person visual or kinesthetic perspectives among the three groups, the yips group exhibited significantly higher vividness of negative motor imagery than the control group in both perspectives. These results indicate that negative motor imagery specific to baseball throwing may be associated with symptoms of yips. Therefore, interventions addressing psychological aspects, such as anxiety, which are potential causes of the generation of negative motor imagery, may be necessary to alleviate the symptoms of yips.

Motor imagery has a priming effect on motor execution in people with multiple sclerosis

Priming is a learning process that refers to behavioral changes caused by previous exposure to a similar stimulus. Motor imagery (MI), which involves the mental rehearsal of action representations in working memory without engaging in actual execution, could be a strategy for priming the motor system. This study investigates whether MI primes action execution in Multiple Sclerosis (MS). Here, 17 people with MS (PwMS) and 19 healthy subjects (HS), all right-handed and good imaginers, performed as accurately and quickly as possible, with a pencil, actual or mental pointing movements between targets of small (1.0 × 1.0 cm) or large (1.5 × 1.5 cm) size. In actual trials, they completed five pointing cycles between the left and right targets, whereas in mental trials, the first 4 cycles were imagined while the fifth was actually executed. The fifth cycle was introduced to assess the MI priming effect on actual execution. All conditions, presented randomly, were performed with both dominant (i.e., right) and non-dominant arms. Analysis of the duration of the first 4 cycles in both actual and mental trials confirmed previous findings, showing isochrony in HS with both arms and significantly faster mental than actual movements (anisochrony) in PwMS (p < 0.01) [time (s); HS right: actual: 4.23 ± 0.15, mental: 4.36 ± 0.16; left: actual: 4.32 ± 0.15, mental: 4.43 ± 0.18; PwMS right: actual: 5.85 ± 0.16, mental: 5.99 ± 0.21; left: actual: 6.68 ± 0.20, mental: 5.94 ± 0.23]; anisochrony in PwMS was present when the task was performed with the non-dominant arm. Of note, temporal analysis of the fifth actual cycle showed no differences between actual and mental trials for HS with both arms, whereas in PwMS the fifth actual cycle was significantly faster after the four actual cycles for the non-dominant arm (p < 0.05) [time (s); HS right: actual: 1.03 ± 0.04, mental: 1.03 ± 0.03; left: actual: 1.08 ± 0.04, mental: 1.05 ± 0.03; PwMS right: actual: 1.48 ± 0.04, mental: 1.48 ± 0.06; left: actual: 1.66 ± 0.05, mental: 1.48 ± 0.06]. These results seem to suggest that a few mental repetitions of an action might be sufficient to exert a priming effect on the actual execution of the same action in PwMS. This would indicate further investigation of the potential use of MI as a new motor-cognitive tool for MS neurorehabilitation.

Factors and strategies affecting motor imagery ability in people with multiple sclerosis: a systematic review

BACKGROUND

Although growing evidence has shown beneficial effects of motor imagery (MI) training in different populations including people with multiple sclerosis (pwMS), not all patients with neurological diseases may benefit from MI.

OBJECTIVES

To investigate factors and strategies affecting and enhancing MI ability in pwMS.

DATA SOURCES

MEDLINE/PubMed, PsycINFO, Cochrane Library, Scopus, EMBASE, EBSCOhost, Web of Science and REHABDATA databases, clinical trials registries, dissertation repositories, study bibliographies and internet search engines were searched through August 2021.

STUDY SELECTION

Any study type but single case studies investigating factors or strategies contributing to MI ability in pwMS.

STUDY APPRAISAL AND SYNTHESIS METHODS

Risk of bias (RoB) was assessed using the Joanna Briggs Institute Checklist for Case-Control and Analytical Cross-Sectional Studies and Cochrane RoB-2.0 tool for randomised trials. A qualitative synthesis was performed summarising main results.

RESULTS

Eight databases, 4 trial registries, 9 dissertation repositories, and 1 internet search engine were searched. Fourteen studies including 366 pwMS and 236 healthy controls were included. Most frequently, cognitive impairment was reported as a negative factor influencing MI ability in pwMS. Other negative factors were cognitive fatigue and disability. Inconsistent evidence was found on the contribution of MS phenotype, anxiety, and depression. Using a theory-based MI framework and familiarisation to MI and external cueing may enhance MI ability.

LIMITATIONS

Eligible studies were highly heterogeneous.

CONCLUSION AND IMPLICATIONS OF KEY FINDINGS

Cognitive impairment, cognitive fatigue and disability negatively influence MI ability in pwMS. Visual and/or auditory cueing of MI are strategies for facilitating MI ability.

SYSTEMATIC REVIEW REGISTRATION NUMBER

PROSPERO CRD42020173081 CONTRIBUTION OF THE PAPER.

Test-Retest Reliability and Criterion Validity of the Spanish Version of Two Motor Imagery Questionnaires in People With Parkinson Disease

BACKGROUND AND PURPOSE

The Kinesthetic and Visual Imagery Questionnaire (KVIQ) and the Movement Imagery Questionnaire-Revised Second Version (MIQ-RS) are measurement instruments that assess motor imagery vividness. The aim of this study was to examine the validity and reliability of the Spanish KVIQ and MIQ-RS in people with Parkinson disease (PD).

METHODS

A longitudinal descriptive study was conducted following the COSMIN standards. Thirty-five people with idiopathic PD were evaluated twice (7-15 days apart) with the Spanish KVIQ and MIQ-RS. Structural validity, internal consistency, test-retest reliability (ICC), standard error of measurement (SEM), smallest detectable change (SDC), and criterion validity of the MIQ-RS and KVIQ long (KVIQ-20), short (KVIQ-10), and extended (KVIQ-34) versions and their subscales (if pertinent) were tested.

RESULTS

Factor analysis was satisfactory for the MIQ-RS, KVIQ-20, and KVIQ-10, providing evidence of their 2-dimensional structure. Evidence of the structural validity of the KVIQ-34 was not confirmed and thus was analyzed as an overall score. Revelle's ω > 0.9 showed excellent internal consistency. Test-retest reliability was moderate (ICC = 0.58-0.75) and higher for all visual subscales. SEM and SDC were up to 14.39% and 39.89% of the scores, respectively. Criterion validity between questionnaires and subscales was strong (Spearman's r > 0.7).

DISCUSSION AND CONCLUSIONS

The results provide evidence for the validity and reliability of the Spanish MIQ-RS, KVIQ-20, and KVIQ-10 to assess motor imagery vividness in people with PD, whereas the KVIQ-34 should only be interpreted as an overall score. Psychometric, procedural, and practical features of the questionnaires should be considered when applying into clinical practice.Video Abstract available for more insights from the authors (see the Video, Supplemental Digital Content 1, available at: http://links.lww.com/JNPT/A401).

Mental Strategies in a P300-BCI: Visuomotor Transformation Is an Option

Currently, P300-BCIs are mostly used for spelling tasks, where the number of commands is equal to the number of stimuli that evoke event-related potentials (ERPs). Increasing this number slows down the BCI operation because each stimulus has to be presented several times for better classification. Furthermore, P300 spellers typically do not utilize potentially useful imagery-based approaches, such as the motor imagery successfully practiced in motor rehabilitation. Here, we tested a P300-BCI with a motor-imagery component. In this BCI, the number of commands was increased by adding mental strategies instead of increasing the number of targets. Our BCI had only two stimuli and four commands. The subjects either counted target appearances mentally or imagined hand movements toward the targets. In this design, the motor-imagery paradigm enacted a visuomotor transformation known to engage cortical and subcortical networks participating in motor control. The operation of these networks suffers in neurological conditions such as stroke, so we view this BCI as a potential tool for the rehabilitation of patients. As an initial step toward the development of this clinical method, sixteen healthy participants were tested. Consistent with our expectation that mental strategies would result in distinct EEG activities, ERPs were different depending on whether subjects counted stimuli or imagined movements. These differences were especially clear in the late ERP components localized in the frontal and centro-parietal regions. We conclude that (1) the P300 paradigm is suitable for enacting visuomotor transformations and (2) P300-based BCIs with multiple mental strategies could be used in applications where the number of possible outputs needs to be increased while keeping the number of targets constant. As such, our approach adds to both the development of versatile BCIs and clinical approaches to rehabilitation.

Effects of actual and imagined music-cued gait training on motor functioning and brain activity in people with multiple sclerosis: protocol of a randomised parallel multicentre trial

INTRODUCTION

Motor imagery (MI) refers to the mental rehearsal of a physical action without muscular activity. Our previous studies showed that MI combined with rhythmic-auditory cues improved walking, fatigue and quality of life (QoL) in people with multiple sclerosis (pwMS). Largest improvements were seen after music and verbally cued MI. It is unclear whether actual cued gait training achieves similar effects on walking as cued MI in pwMS. Furthermore, in pwMS it is unknown whether any of these interventions leads to changes in brain activation. The purpose of this study is therefore to compare the effects of imagined and actual cued gait training and a combination thereof on walking, brain activation patterns, fatigue, cognitive and emotional functioning in pwMS.

METHODS AND ANALYSIS

A prospective double-blind randomised parallel multicentre trial will be conducted in 132 pwMS with mild to moderate disability. Randomised into three groups, participants will receive music, metronome and verbal cueing, plus MI of walking (1), MI combined with actual gait training (2) or actual gait training (3) for 30 min, 4× per week for 4 weeks. Supported by weekly phone calls, participants will practise at home, guided by recorded instructions. Primary endpoints will be walking speed (Timed 25-Foot Walk) and distance (2 min Walk Test). Secondary endpoints will be brain activation patterns, fatigue, QoL, MI ability, anxiety, depression, cognitive functioning, music-induced motivation-to-move, pleasure, arousal and self-efficacy. Data will be collected at baseline, postintervention and 3-month follow-up. MRI reference values will be generated using 15 matched healthy controls.

ETHICS AND DISSEMINATION

This study follows the Standard Protocol Items: Recommendations for Interventional Trials-PRO Extension. Ethical approval was received from the Ethics Committees of the Medical Universities of Innsbruck (1347/2020) and Graz (33-056 ex 20/21), Austria. Results will be disseminated via national and international conferences and published in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

DRKS00023978.

Motor Imagery of Walking in People Living with and without Multiple Sclerosis: A Cross-Sectional Comparison of Mental Chronometry

Motor imagery represents the ability to simulate anticipated movements mentally prior to their actual execution and has been proposed as a tool to assess both individuals’ perception of task difficulty as well as their perception of their own abilities. People with multiple sclerosis (pwMS) often present with motor and cognitive dysfunction, which may negatively affect motor imagery. In this cross-sectional study, we explored differences in motor imagery of walking performance between pwMS (n = 20, age = 57.1 (SD = 8.6) years, 55% female) and age- and sex-matched healthy controls (n = 20, age = 58.1 (SD = 7.0) years, 60% female). Participants underwent mental chronometry assessments, a subset of motor imagery, which evaluated the difference between imagined and actual walking times across four walking tasks of increasing difficulty (i.e., large/narrow-width walkway with/without obstacles). Raw and absolute mental chronometry (A-MC) measures were recorded in single- (ST) and dual-task (DT) conditions. In ST conditions, pwMS had higher A-MC scores across all walking conditions (p ≤ 0.031, η² ≥ 0.119), indicating lower motor imagery ability compared to healthy controls. During DT, all participants tended to underestimate their walking ability (3.38 ± 6.72 to 5.63 ± 9.17 s). However, after physical practice, pwMS were less able to adjust their imagined walking performance compared to healthy controls. In pwMS, A-MC scores were correlated with measures of balance confidence (ρ = −0.629, p < 0.01) and the self-reported expanded disability status scale (ρ = 0.747, p < 0.01). While the current study revealed that pwMS have lower motor imagery of walking performance compared to healthy individuals, further work is necessary to examine how the disassociation between mental chronometry and actual performance relates to quality of life and well-being.

Effectiveness of Motor Imagery on Motor Recovery in Patients with Multiple Sclerosis: Systematic Review

The effects of motor imagery (MI) on functional recovery of patients with neurological pathologies, such as stroke, has been recently proven. The aim of this study is to evaluate the effectiveness of MI on motor recovery and quality of life (QOL) in patients with multiple sclerosis (pwMS). A search was carried out in the following scientific databases: PubMed, CINAHL, PEDro, Scopus, Cochrane and Web of Science, up to November 2020. The grey literature and reference lists of potentially relevant articles were also searched. The Checklist for Measuring Quality and The Cochrane collaboration’s tool were used to assess the methodological quality and risk of bias of the studies. Five studies were included in the systematic review. Findings showed that pwMS using MI had significant improvements in walking speed and distance, fatigue and QOL. In addition, several benefits were also found in dynamic balance and perceived walking ability. Although the evidence is limited, rehabilitation using MI with the application of musical and verbal guides (compared to non-intervention or other interventions), can produce benefits on gait, fatigue and QOL in pwMS with a low score in the Expanded Disability Status Scale.

The effect of handedness on mental rotation of hands: a systematic review and meta-analysis

Body-specific mental rotation is thought to rely upon internal representations of motor actions. Handedness is a source of distinctly different motor experience that shapes the development of such internal representations. Yet, the influence of handedness upon hand mental rotation has never been systematically evaluated. Five databases were searched for studies evaluating hand left/right judgement tasks in adults. Two independent reviewers performed screening, data extraction, and critical appraisal. Eighty-seven datasets were included, with 72 datasets pooled; all had unclear/high risk of bias. Meta-analyses showed that right-handers were faster, but not more accurate, than left-handers at hand mental rotation. A unique effect of handedness was found on performance facilitation for images corresponding to the dominant hand. Meta-analyses showed that right-handers were quicker at identifying images of right hands than left hands-a dominance advantage not evident in left-handers. Differing hand representations (more lateralised hand dominance in right-handers) likely underpin these findings. Given potential differences between hand preference and motor performance, future research exploring their distinct contributions to mental rotation is warranted.

Spatial constraints and cognitive fatigue affect motor imagery of walking in people with multiple sclerosis

Motor imagery (MI) is the mental simulation of an action without any overt motor execution. Interestingly, a temporal coupling between durations of real and imagined movements, i.e., the so-called isochrony principle, has been demonstrated in healthy adults. On the contrary, anisochrony has frequently been reported in elderly subjects or those with neurological disease such as Parkinson disease or multiple sclerosis (MS). Here, we tested whether people with MS (PwMS) may have impaired MI when they imagined themselves walking on paths with different widths. When required to mentally simulate a walking movement along a constrained pathway, PwMS tended to overestimate mental movement duration with respect to actual movement duration. Interestingly, in line with previous evidence, cognitive fatigue was found to play a role in the MI of PwMS. These results suggest that investigating the relationship between cognitive fatigue and MI performances could be key to shedding new light on the motor representation of PwMS and providing critical insights into effective and tailored rehabilitative treatments.

Influence of RehaCom Therapy on the Improvement of Manual Skills in Multiple Sclerosis Subjects

Objective

To assess the influence of cognitive therapy, in combination with cognitive software, on manual dexterity in individuals with multiple sclerosis (MS).

Methods

The Nine-Hole Peg Test (NHPT) was used to establish the eligibility of individuals with MS for testing and to assess their upper limb performance. In addition to standard upper limb rehabilitation, 20 participants received RehaCom-based visual-motor therapy, administered three times a week in 20-minute routines.

Results

A significant relationship was found between the use of manual therapy that utilized the cognitive function platform and the improvement of the non-dominant hand (p=0.037). Compared to controls, the experimental group scored higher on the NHPT, when using the dominant hand (p=0.007). All members of the experimental group, aged ≤60 years, needed considerably less time to do the NHPT with the dominant hand (p=0.008).

Conclusion

Application of manual therapy using the cognitive function platform improves performance of the hand. However, further research is needed to analyze the correlation between cognitive function and motor performance in patients with MS.

Language evolution to revolution: the leap from rich-vocabulary non-recursive communication system to recursive language 70,000 years ago was associated with acquisition of a novel component of imagination, called Prefrontal Synthesis, enabled by a mutation that slowed down the prefrontal cortex maturation simultaneously in two or more children – the Romulus and Remus hypothesis

There is an overwhelming archeological and genetic evidence that modern speech apparatus was acquired by hominins by 600,000 years ago. On the other hand, artifacts signifying modern imagination, such as (1) composite figurative arts, (2) bone needles with an eye, (3) construction of dwellings, and (4) elaborate burials arose not earlier than 70,000 years ago. It remains unclear (1) why there was a long gap between acquisition of modern speech apparatus and modern imagination, (2) what triggered the acquisition of modern imagination 70,000 years ago, and (3) what role language might have played in this process. Our research into evolutionary origin of modern imagination has been driven by the observation of a temporal limit for the development of a particular component of imagination. Modern children not exposed to recursive language in early childhood never acquire the type of active constructive imagination called Prefrontal Synthesis (PFS). Unlike vocabulary and grammar acquisition, which can be learned throughout one’s lifetime, there is a strong critical period for the development of PFS and individuals not exposed to recursive language in early childhood can never acquire PFS as adults. Their language will always lack understanding of spatial prepositions and recursion that depend on the PFS ability. In a similar manner, early hominins would not have been able to learn recursive language as adults and, therefore, would not be able to teach recursive language to their children. Thus, the existence of a strong critical period for PFS acquisition creates an evolutionary barrier for behavioral modernity. An evolutionary mathematical model suggests that a synergistic confluence of three events (1) a genetic mutation that extended the critical period by slowing down the prefrontal cortex development simultaneously in two or more children, (2) invention of recursive elements of language, such as spatial prepositions, by these children and (3) their dialogic communications using these recursive elements, resulted in concurrent conversion of a non-recursive communication system of their parents to recursive language and acquisition of PFS around 70,000 years ago.

Physical, cognitive and psychosocial effects of telerehabilitation-based motor imagery training in people with multiple sclerosis: A randomized controlled pilot trial

INTRODUCTION

Motor imagery training delivered at home via telerehabilitation is a novel rehabilitation concept. The aim was to investigate the effects of telerehabilitation-based motor imaging training (Tele-MIT) on gait, balance and cognitive and psychosocial outcomes in people with multiple sclerosis (pwMS).

METHODS

This randomized, controlled pilot trial included pwMS and healthy individuals. pwMS were randomly divided into two groups, intervention and control. The intervention group received Tele-MIT twice a week for 8 weeks. The control group was a wait-list group without any additional specific treatment. Healthy participants served as a baseline comparison. The Dynamic Gait Index, used to assess dynamic balance during walking, was the primary outcome. Secondary outcomes included assessments of walking speed, endurance and perceived ability, balance performance assessed by a computerized posturography device, balance confidence, cognitive functions, fatigue, anxiety, depression and quality of life.

RESULTS

Baseline comparisons with healthy individuals revealed that motor imagery abilities were preserved in pwMS (p > 0.05). The intervention group exhibited significant improvements in dynamic balance during walking (p = 0.002), walking speed (p = 0.007), perceived walking ability (p = 0.008), balance confidence (p = 0.002), most cognitive functions (p = 0.001-0.008), fatigue (p = 0.001), anxiety (p = 0.001), depression (p = 0.005) and quality of life (p = 0.002). No significant changes were observed in the control group in any of the outcome measures (p > 0.05).

DISCUSSION

Tele-MIT is a novel method that proved feasible and effective in improving dynamic balance during walking, walking speed and perceived walking ability, balance confidence, cognitive functions, fatigue, anxiety, depression and quality of life in pwMS.

Motor imagery in multiple sclerosis: exploring applications in therapeutic treatment

Motor imagery (MI) is a promising rehabilitation technique that has received significant interest for use in persons with multiple sclerosis (MS). Through alterations in neural networks, MI has the potential to improve measures of walking speed, walking distance, and fatigue in people with MS. Further research is required to assess the validity of MI in conjunction with other therapeutic MS treatments and provide objective outcome measures of motor improvements.

Effects and mechanisms of differently cued and non-cued motor imagery in people with multiple sclerosis: A randomised controlled trial

BACKGROUND

Walking impairment and fatigue are prevalent symptoms in people with multiple sclerosis (PwMS). Motor imagery (MI) with rhythmic auditory cueing improved walking in PwMS, but so far, the underlying mechanisms are not fully explored.

OBJECTIVE

This study investigated the effects and mechanisms of differently cued and non-cued MI on walking, fatigue and quality of life (QoL) in PwMS.

METHODS

A total of 60 PwMS with mild to moderate disability were randomised to music- and verbally cued MI (MVMI), music-cued MI (MMI) or MI. Participants practised cued or non-cued MI of walking for 17 minutes, six times per week for 4 weeks at home. Primary outcomes were walking speed (timed 25-foot walk) and walking distance (6-minute walk test).

RESULTS

A total of 59 participants completed the study. All interventions induced significant improvements in walking speed and distance, while MVMI was superior. After cued MI, fatigue and QoL significantly improved, with greatest changes seen after MVMI. All participants showed high MI ability. Post-intervention, sensorimotor synchronisation (SMS) was significantly more accurate after cued MI.

CONCLUSION

All interventions significantly improved walking. MVMI was superior in improving walking, fatigue and QoL. Results suggest that MI and SMS were mechanisms of action.

Dual-task cost in people with multiple sclerosis: A case–control study

Introduction

Limitations in fine motor functioning and cognitive performance are frequently reported in multiple sclerosis. Studies about dual-task costs in multiple sclerosis generally explore walking and postural performance. This study aims at exploring dual-task costs when simultaneously performing fine motor and cognitive tasks.

Method

Eighty people with multiple sclerosis and 80 matched controls performed the nine-hole peg test and the months backward test under single and dual-task conditions. Differences in performance over time were analysed with the paired t-test; differences in dual-task costs between groups were analysed with independent t-tests.

Results

People with multiple sclerosis and controls showed a significant decrease in fine motor and cognitive performance in dual-task conditions compared to single-task conditions ( P < 0.01). People with multiple sclerosis with limited hand capacity showed larger dual-task costs for cognitive performance compared to other hand capacity groups ( P < 0.05). Individuals with multiple sclerosis with lower cognitive capacity showed larger dual-task costs for fine motor performance ( P < 0.01).

Conclusion

Both people with multiple sclerosis and controls experience dual-task costs. People with multiple sclerosis with limited hand function showed an increased dual-task cost of cognitive performance and individuals with limited cognitive capacity showed a higher dual-task cost for fine motor performance. Therefore, occupational therapists should focus on cognitive or fine motor aspects during dual-task training dependent on individuals' capacities.

Exploring cued and non-cued motor imagery interventions in people with multiple sclerosis: a randomised feasibility trial and reliability study

Background

Motor imagery (MI) is increasingly used in neurorehabilitation to facilitate motor performance. Our previous study results demonstrated significantly improved walking after rhythmic-cued MI in people with multiple sclerosis (pwMS). The present feasibility study was aimed to obtain preliminary information of changes in walking, fatigue, quality of life (QoL) and MI ability following cued and non-cued MI in pwMS. The study further investigated the feasibility of a larger study and examined the reliability of a two-dimensional gait analysis system.

Methods

At the MS-Clinic, Department of Neurology, Medical University of Innsbruck, Austria, 15 adult pwMS (1.5–4.5 on the Expanded Disability Status Scale, 13 females) were randomised to one of three groups: 24 sessions of 17 min of MI with music and verbal cueing (MVMI), with music alone (MMI), or non-cued (MI). Descriptive statistics were reported for all outcomes. Primary outcomes were walking speed (Timed 25-Foot Walk) and walking distance (6-Minute Walk Test). Secondary outcomes were recruitment rate, retention, adherence, acceptability, adverse events, MI ability (Kinaesthetic and Visual Imagery Questionnaire, Time-Dependent MI test), fatigue (Modified Fatigue Impact Scale) and QoL (Multiple Sclerosis Impact Scale-29). The reliability of a gait analysis system used to assess gait synchronisation with music beat was tested.

Results

Participants showed adequate MI abilities. Post-intervention, improvements in walking speed, walking distance, fatigue, QoL and MI ability were observed in all groups. Success of the feasibility criteria was demonstrated by recruitment and retention rates of 8.6% (95% confidence interval, CI 5.2, 13.8%) and 100% (95% CI 76.4, 100%), which exceeded the target rates of 5.7% and 80%. Additionally, the 83% (95% CI 0.42, 0.99) adherence rate surpassed the 67% target rate. Intra-rater reliability analysis of the gait measurement instruments demonstrated excellent Intra-Class Correlation coefficients for step length of 0.978 (95% CI 0.973, 0.982) and step time of 0.880 (95% CI 0.855, 0.902).

Conclusion

Results from our study suggest that cued and non-cued MI are valuable interventions in pwMS who were able to imagine movements. A larger study appears feasible, however, substantial improvements to the methods are required such as stratified randomisation using a computer-generated sequence and blinding of the assessors.

Trial registration

ISRCTN ISRCTN92351899. Registered 10 December 2015.

Electronic supplementary material

The online version of this article (10.1186/s40945-018-0045-0) contains supplementary material, which is available to authorized users.

Object decision and multiple sclerosis: a preliminary study

The aim of this research was to study cognitive dysfunctions in multiple sclerosis (MS) by exploring subtle cognitive tasks, usually not included in the standard neuropsychological assessment. We wished to investigate whether it is possible to identify object decision deficits in MS patients without evident cognitive impairment; secondary objectives were to understand whether these deficits can be detected in the early stages of the disease and whether there are differences related to different phenotypes. Participants were divided into four groups: (a) 12 patients with early relapsing-remitting MS [ERR]; (b) 14 with late relapsing-remitting MS [LRR]; (c) 10 with secondary progressive MS [SP]; (d) 36 healthy controls [HCs]. All participants performed a series of experimental tasks: an object decision task (recognition of chimeric and real figures) and naming and visual discrimination tasks. Our results suggest that object decision disorders are detectable in patients without overt cognitive impairments and that performances on these tasks are related to phenotypes. On the other hand, the Chimeric Figures task is not appropriate for identifying cognitive dysfunctions in early MS.

Motor Imagery as a Function of Disease Severity in Multiple Sclerosis: An fMRI Study

Motor imagery (MI) is defined as mental execution without any actual movement. While healthy adults usually show temporal equivalence, i.e., isochrony, between the mental simulation of an action and its actual performance, neurological disorders are associated with anisochrony. Unlike in patients with stroke and Parkinson disease, only a few studies have investigated differences of MI ability in multiple sclerosis (MS). However, the relationship among disease severity, anisochrony and brain activation patterns during MI has not been investigated yet. Here, we propose to investigate MI in MS patients using fMRI during a behavioral task executed with dominant/non-dominant hand and to evaluate whether anisochrony is associated with disease severity. Thirty-seven right-handed MS patients, 17 with clinically isolated syndrome (CIS) suggestive of MS and 20 with relapsing-remitting MS (RR-MS) and 20 right-handed healthy controls (HC) underwent fMRI during a motor task consisting in the actual or imaged movement of squeezing a foam ball with the dominant and non-dominant hand. The same tasks were performed outside the MRI room to record the number of actual and imagined ball squeezes, and calculate an Index of performance (IP) based on the ratio between actual and imagined movements. IP showed that a progressive loss of ability in simulating actions (i.e., anisochrony) more pronounced for non-dominant hand, was found as function of the disease course. Moreover, anisochrony was associated with activation of occipito-parieto-frontal areas that were more extensive at the early stages of the disease, probably in order to counteract the changes due to MS. However, the neural engagement of compensatory brain areas becomes more difficult with more challenging tasks, i.e., dominant vs. non-dominant hand, with a consequent deficit in behavioral performance. These results show a strict association between MI performance and disease severity, suggesting that, at early stages of the disease, anisochrony in MI could be considered as surrogate behavioral marker of MS severity.

Resting-state functional connectivity and motor imagery brain activation

Motor imagery (MI) relies on the mental simulation of an action without any overt motor execution (ME), and can facilitate motor learning and enhance the effect of rehabilitation in patients with neurological conditions. While functional magnetic resonance imaging (fMRI) during MI and ME reveals shared cortical representations, the role and functional relevance of the resting-state functional connectivity (RSFC) of brain regions involved in MI is yet unknown. Here, we performed resting-state fMRI followed by fMRI during ME and MI with the dominant hand. We used a behavioral chronometry test to measure ME and MI movement duration and compute an index of performance (IP). Then, we analyzed the voxel-matched correlation between the individual MI parameter estimates and seed-based RSFC maps in the MI network to measure the correspondence between RSFC and MI fMRI activation. We found that inter-individual differences in intrinsic connectivity in the MI network predicted several clusters of activation. Taken together, present findings provide first evidence that RSFC within the MI network is predictive of the activation of MI brain regions, including those associated with behavioral performance, thus suggesting a role for RSFC in obtaining a deeper understanding of neural substrates of MI and of MI ability. Hum Brain Mapp 37:3847-3857, 2016. © 2016 Wiley Periodicals, Inc.

Neurobiological mechanisms for nonverbal IQ tests: implications for instruction of nonverbal children with autism

Traditionally, the neurological correlates of IQ test questions are characterized qualitatively in terms of ‘control of attention’ and ‘working memory.’ In this report we attempt to characterize each IQ test question quantitatively by two factors: a) the number of disparate objects that have to be imagined in concert in order to solve the problem and, b) the amount of recruited posterior cortex territory. With such a classification, an IQ test can be understood on a neuronal level and a subject’s IQ score could be interpreted in terms of specific neurological mechanisms available to the subject.

Here we present the results of an analysis of the three most popular nonverbal IQ tests: Test of Nonverbal Intelligence (TONI-4), Standard Raven's Progressive Matrices, and Wechsler Intelligence Scale for Children (WISC-V). Our analysis shows that approximately half of all questions (52±0.02%) are limited to mental computations involving only a single object; these easier questions are found towards the beginning of each test. More difficult questions located towards the end of each test rely on mental synthesis of several disparate objects and the number of objects involved in computations gradually increases with question difficulty. These more challenging questions require the organization of wider posterior cortex networks by the lateral prefrontal cortex (PFC). This conclusion is in line with neuroimaging studies showing that activation level of the lateral PFC and the posterior cortex positively correlates with task difficulty. This analysis has direct implications for brain pathophysiology and, specifically, for therapeutic interventions for children with language impairment, most notably for children with Autism Spectrum Disorder (ASD) and other developmental disorders.

The effect of rhythmic-cued motor imagery on walking, fatigue and quality of life in people with multiple sclerosis: A randomised controlled trial

BACKGROUND

Motor imagery and rhythmic auditory stimulation are physiotherapy strategies for walking rehabilitation.

OBJECTIVES

To investigate the effect of motor imagery combined with rhythmic cueing on walking, fatigue and quality of life (QoL) in people with multiple sclerosis (MS).

METHODS

Individuals with MS and Expanded Disability Status Scale scores of 1.5-4.5 were randomised into one of three groups: 17 minutes of motor imagery, six times per week, for 4 weeks, with music (A) or metronome cues (B), both with verbal cueing, and (C) controls. Primary outcomes were walking speed (Timed 25-Foot Walk) and distance (6-Minute Walk Test). Secondary outcomes were walking perception (Multiple Sclerosis Walking Scale-12), fatigue (Modified Fatigue Impact Scale) and QoL (Short Form-36 Health Survey, Multiple Sclerosis Impact Scale-29, Euroquol-5D-3L Questionnaire).

RESULTS

Of the 112 participants randomised, 101 completed the study. Compared to controls, both interventions significantly improved walking speed, distance and perception. Significant improvements in cognitive but not psychosocial fatigue were seen in the intervention groups, and physical fatigue improved only in the music-based group. Both interventions improved QoL; however, music-cued motor imagery was superior at improving health-related QoL.

CONCLUSION

Rhythmic-cued motor imagery improves walking, fatigue and QoL in people with MS, with music-cued motor imagery being more effective.

Rhythmic cued motor imagery and walking in people with multiple sclerosis: a randomised controlled feasibility study

BACKGROUND

Novel physiotherapy approaches such as motor imagery and rhythmic auditory stimulation have been shown to improve walking in people with multiple sclerosis (MS). Rhythmic cued motor imagery was used in this study, whose objectives were to evaluate the feasibility of a larger randomised controlled trial (RCT) in people with MS and to obtain information on walking.

METHODS

Thirty adult people with MS who scored 1.5-4.5 on the Expanded Disability Status Scale were recruited at the MS Clinic Innsbruck, Austria. Participants were randomly allocated to one of three groups, all receiving usual care: 17 min of motor imagery, six times per week, for 4 weeks, with music (A) or metronome cues (B) and (C) controls. Primary outcomes were recruitment rates, retention, compliance, adverse events and fatigue (Modified Fatigue Impact Scale). Secondary outcomes were walking speed (Timed 25-Foot Walk) and walking distance (6-Minute Walk Test).

RESULTS

We achieved our recruitment target by recruiting 12 participants per month, a mean eligibility rate of 40.1 % (95 % confidence interval (CI) 35.8, 44.6 %) out of 2500 MS Centre patients, mean consent rate of 15.9 % (95 % CI 11.3, 21.7 %) plus 54.5 % (95 % CI 47.4, 61.4 %) of eligible patients who expressed their interest to participate. Retention of 100 %, no adverse events, good compliance, high acceptability of the interventions and no worsening of fatigue confirmed feasibility. The mean improvement in walking speed in both groups A and B was -0.9 s (95 % CI -1.3, -0.5), and mean worsening in group C was 0.4 s (95 % CI -0.3, 1.1). The mean improvement in walking distance in group A was 68.1 m (95 % CI 51.4, 84.7) and in group B 92.9 m (95 % CI 55.2, 130.5), and mean worsening in group C was -9.4 m (95 % CI -35.6, 16.9).

CONCLUSIONS

Results from our study showed that a full-scale RCT is feasible to investigate the effects of rhythmic cued motor imagery on walking in people with MS, with no changes to the interventions and assessments. Based on the walking improvements, a total sample size of 138 participants was calculated. Stratified blocked randomisation, allocation concealment and blinding will be used in the main study.

TRIAL REGISTRATION

ISRCTN: ISRCTN67054113.

Assessing motor imagery ability in younger and older adults by combining measures of vividness, controllability and timing of motor imagery

With the population aging, a large number of patients undergoing rehabilitation are older than 60 years. Also, since the use of motor imagery (MI) training in rehabilitation is becoming more popular, it is important to gain a better knowledge about the age-related changes in MI ability. The main goal of this study was to compare MI ability in younger and older adults as well as to propose a new procedure for testing this ability. Thirty healthy young subjects (mean age: 22.9±2.7 years) and 28 healthy elderly subjects (mean age: 72.4±5.5 years) participated in the experiment. They were administered three tests aimed at assessing three dimensions of MI: (1) the kinesthetic and visual imagery questionnaire (KVIQ) to assess MI vividness; (2) a finger-thumb opposition task to assess MI controllability; and (3) a chronometric task to assess the timing of MI. On average, the younger and older groups showed similar results on the KVIQ and the chronometric task, but the younger group was more accurate at the finger-thumb opposition task. Interestingly, there was a large variability in the performance within both groups, emphasizing the importance of considering each person individually regarding MI ability, whatever his age. Finally, we propose two indexes of MI ability to identify the potential of persons to engage in MI training programs. Future studies are needed to confirm the predictive value of these MI indexes and define inclusion/exclusion thresholds for their use as a screening tool in both younger and older adults.

Motor imagery in unipolar major depression

Background: Motor imagery is a potential tool to investigate action representation, as it can provide insights into the processes of action planning and preparation. Recent studies suggest that depressed patients present specific impairment in mental rotation. The present study was designed to investigate the influence of unipolar depression on motor imagery ability.

Methods: Fourteen right-handed patients meeting DSM-IV criteria for unipolar depression were compared to 14 matched healthy controls. Imagery ability was accessed by the timing correspondence between executed and imagined movements during a pointing task, involving strong spatiotemporal constraints (speed/accuracy trade-off paradigm).

Results: Compared to controls, depressed patients showed marked motor slowing on both actual and imagined movements. Furthermore, we observed greater temporal discrepancies between actual and mental movements in depressed patients than in healthy controls. Lastly, depressed patients modulated, to some extent, mental movement durations according to the difficulty of the task, but this modulation was not as strong as that of healthy subjects.

Conclusion: These results suggest that unipolar depression significantly affects the higher stages of action planning and point out a selective decline of motor prediction.

Abnormalities of motor imagery and relationship with depressive symptoms in mildly disabling relapsing-remitting multiple sclerosis

BACKGROUND AND PURPOSE

The effectiveness of motor imagery (MI) as an adjunct to physical rehabilitation has previously been shown. Motor imagery ability can be affected by neurologic disorders that affect motor and cognitive function. This study was designed to assess MI ability in persons with mildly disabling relapsing-remitting multiple sclerosis (RRMS) based on the functional and cognitive dysfunctions.

METHODS

Twenty-two participants with RRMS and 23 age-, gender-, and education-matched comparison subjects were evaluated by a battery of MI tasks, including a kinesthetic and visual imagery questionnaire, a mental hand rotation task, and a visual guided pointing task.

RESULTS

There was no significant difference in MI vividness between the participants with MS and the comparison group, but the accuracy and temporal correspondence of MI in the participants with MS differed significantly from those in the comparison group. Depression scores were significantly higher in participants with MS (P < 0.001), and depression was significantly correlated with disability (r = 0.4; P < 0.05). The correlation between accuracy of MI in the participants with MS and their cognitive ability was significant (r = 0.57; P < 0.05). The MI duration of participants with MS was significantly correlated with their disability (r = 0.59; P < 0.05) and their cognitive ability (r = -0.38; P = 0.009).

DISCUSSION

The preservation of MI ability was observed in participants with RRMS; however, abnormalities in accuracy and temporal aspects of MI were observed even in the participants with mild disease. Abnormalities in temporal aspects and accuracy of MI were related to disability and cognitive ability, respectively. In participants with MS, depression should be considered as a confounding factor for the MI task results.

CONCLUSIONS

Our finding could be considered in the application of MI during the rehabilitation of persons with MS.

Upper limb assessment in multiple sclerosis: a systematic review of outcome measures and their psychometric properties

OBJECTIVE

To provide an overview of applied upper limb outcome measures in multiple sclerosis (MS) according to the International Classification of Functioning, Disability and Health (ICF) levels and to review their psychometric properties in MS.

DATA SOURCES

PubMed and Web of Knowledge.

STUDY SELECTION

Articles published until June 2013 were selected when written in English, published in the last 25 years, peer reviewed, including >5 persons with MS, and including standardized clinical upper limb outcome measures. Included articles were screened based on title/abstract and full text by 2 independent reviewers. In case of doubt, feedback from a third independent reviewer was obtained. Additionally, references lists were checked for relevant articles. Of the articles, 109 met the selection criteria and were included for data extraction.

DATA EXTRACTION

All reported clinical upper limb outcome measures were extracted from the included studies and classified according to the ICF levels by 2 independent reviewers. In addition, available psychometric properties (reliability, validity, responsiveness) in MS were summarized and discussed.

DATA SYNTHESIS

A diversity of outcome measures assessing impairments on the body functions and structures level (n=33), upper limb capacity (n=11), and performance (n=8) on the activity level were extracted from 109 articles. Hand grip strength and the nine-hole peg test (NHPT) were the most frequently used outcome measures. However, multiple outcome measures are necessary to encapsulate the multidimensional character of the upper limb function. The psychometric properties were insufficiently documented for most of the outcome measures, except for the NHPT.

CONCLUSIONS

The results of this review may help with the selection of appropriate outcome measures and may guide future research regarding the psychometric properties in MS.

The reliability and validity study of the Kinesthetic and Visual Imagery Questionnaire in individuals with multiple sclerosis

Objective

Motor imagery (MI) has been recently considered as an adjunct to physical rehabilitation in patients with multiple sclerosis (MS). It is necessary to assess MI abilities and benefits in patients with MS by using a reliable tool. The Kinesthetic and Visual Imagery Questionnaire (KVIQ) was recently developed to assess MI ability in patients with stroke and other disabilities. Considering the different underlying pathologies, the present study aimed to examine the validity and reliability of the KVIQ in MS patients.

Method

Fifteen MS patients were assessed using the KVIQ in 2 sessions (5-14days apart) by the same examiner. In the second session, the participants also completed a revised MI questionnaire (MIQ-R) as the gold standard. Intra-class correlation coefficients (ICCs) were measured to determine test-retest reliability. Spearman's correlation analysis was performed to assess concurrent validity with the MIQ-R. Furthermore, the internal consistency (Cronbach's alpha) and factorial structure of the KVIQ were studied.

Results

The test-retest reliability for the KVIQ was good (ICCs: total KVIQ=0.89, visual KVIQ=0.85, and kinesthetic KVIQ=0.93), and the concurrent validity between the KVIQ and MIQ-R was good (r=0.79). The KVIQ had good internal consistency, with high Cronbach's alpha (alpha=0.84). Factorial analysis showed the bi-factorial structure of the KVIQ, which was explained by visual=57.6% and kinesthetic=32.4%.

Conclusions

The results of the present study revealed that the KVIQ is a valid and reliable tool for assessing MI in MS patients.

The effects of mental practice in neurological rehabilitation; a systematic review and meta-analysis

Objective: To investigate the beneficial and adverse effects of a mental practice intervention on activities, cognition, and emotion in patients after stroke, patients with Parkinson's disease or multiple sclerosis.

Methods: Electronic databases PubMed/Medline, PEDro, Science Direct, Cochrane Library, PsycINFO, Rehadat, Embase, and Picarta were searched until June 2012. Fourteen randomized controlled trials in stroke and two randomized controlled trials in Parkinson's disease were included, representing 491 patients (421 with stroke). No randomized controlled trials in multiple sclerosis were identified. The methodologic quality of the included trials was assessed with the Amsterdam-Maastricht-Consensus-List (AMCL). Information on study characteristics and outcomes was summarized and evidence for effects described. Data from individual studies in stroke with same outcome measures were pooled.

Results: The included 16 randomized controlled trials were heterogeneous and methodologic quality varied. Ten trials reported significant effects in favor of mental practice in patients with stroke (n = 9) and Parkinson's disease (n = 1). In six studies mental practice had similar effects as therapy as usual (n = 5 in stroke and n = 1 in Parkinson's disease). Of six performed meta-analyses with identical measures in stroke studies only two showed significant effects of mental practice: short-term improvement of arm-hand-ability (ARAT: SMD 0.62; 95% CI: 0.05 to 1.19) and improvement of performance of activities (NRS: SMD 0.9; 95% CI: 0.04 to 1.77). Five studies found effects on cognition (e.g., effects on attention, plan actions in unfamiliar surroundings) and four reported observed side-effects, both positive (e.g., might increase motivation and arousal and reduce depression) and negative (e.g., diminished concentration, irritation).

Conclusions: Mental practice might have positive effects on performance of activities in patients with neurological diseases, but this review reports less positive results than earlier published ones. Strengths and limitations of past studies are pointed out. Methodologic recommendations for future studies are given.

Walking execution is not affected by divided attention in patients with multiple sclerosis with no disability, but there is a motor planning impairment

Purpose: We analysed the cognitive influence on walking in multiple sclerosis (MS) patients, in the absence of clinical disability. Method: A case-control study was conducted with 12 MS patients with no disability and 12 matched healthy controls. Subjects were referred for completion a timed walk test of 10 m and a 3D-kinematic analysis. Participants were instructed to walk at a comfortable speed in a dual-task (arithmetic task) condition, and motor planning was measured by mental chronometry. Results: Scores of walking speed and cadence showed no statistically significant differences between the groups in the three conditions. The dual-task condition showed an increase in the double support duration in both groups. Motor imagery analysis showed statistically significant differences between real and imagined walking in patients. Conclusion: MS patients with no disability did not show any influence of divided attention on walking execution. However, motor planning was overestimated as compared with real walking.

Imagined actions in multiple sclerosis patients: evidence of decline in motor cognitive prediction

Motor imagery is a mental process during which subjects internally simulate a movement without any motor output. Mental and actual movement durations are similar in healthy adults (isochrony) while temporal discrepancies (anisochrony) could be an expression of neurological deficits on action representation. It is unclear whether patients with multiple sclerosis (PwMS) preserve the capacity to simulate their own movements. This study investigates the ability of PwMS to predict their own actions by comparing temporal features of dominant and non-dominant actual and mental actions. Fourteen PwMS and nineteen healthy subjects (HS) were asked to execute and to imagine pointing arm movements among four pairs of targets of different sizes. Task duration was calculated for both actual and mental movements by an optoelectronic device. Results showed temporal consistency and target-by-target size modulation in actual movements through the four cycles for both groups with significantly longer actual and mental movement durations in PwMS with respect to HS. An index of performance (IP) was used to examine actual/mental isochrony properties in the two groups. Statistical analysis on IP showed in PwMS significantly longer actual movement durations with respect to mental movement durations (anisochrony), more relevant for the non-dominant than dominant arm. Mental prediction of motor actions is not well preserved in MS where motor and cognitive functional changes are present. Differences in performing imagined task with dominant and non-dominant arm could be related to increased cognitive effort required for performing non-dominant movements.

Compromised motor imagery ability in individuals with multiple sclerosis and mild physical disability: an ERP study

BACKGROUND

Motor imagery (MI) impairment has been reported in individuals with multiple sclerosis (MS). The present study was designed to investigate neural evidence for MI impairment and its relationship to working memory in MS patients.

METHODS

The study participants included 24 early stage MS patients (age: 22-40/mean=32.7 years; M/F=4/20; years since duration: 1-10/mean=5.8) and 24 age-, gender-, and education-matched controls (age: 21-40/mean=31.8 years; M/F=5/19). Event-related potentials were recorded during a mental hand rotation task, in which participants were instructed to judge the laterality of hands displayed in different orientations. Furthermore, the Paced Auditory Serial Addition Test (PASAT) was used for assessment of working memory.

RESULTS

At the behavioral level, MS patients were significantly less accurate and much slower (accuracy: 83.80 ± 7.72%; reaction time: 1665.95 ± 269.82 ms) than controls (accuracy: 88.35 ± 7.68%; reaction time: 1505.16 ± 225.11 ms). At the neural level, MS patients showed a significantly reduced amplitude (MS: 0.99 ± 0.89 μv, controls: 1.46 ± 1.00 μv) and delayed peak latency (MS: 458.45 ± 67.60 ms, controls: 417.91 ± 62.47 ms) at P3 for mental rotation effect. Moreover, there were significant correlations between individuals' PASAT scores and performance of the hand rotation task.

CONCLUSION

The results of the present study demonstrate MI impairment in patients with MS at both the behavioral and neural level. Neuronal activity dysfunction (decreased and delayed activity) in patients with MS provides new insights into MI impairment. Furthermore, our findings suggest the contribution of working memory dysfunction to compromised MI ability in patients with MS.