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.

Motor imagery ability scores are related to cortical activation during gait imagery.

Motor imagery (MI) is the mental execution of actions without overt movements that depends on the ability to imagine. We explored whether this ability could be related to the cortical activity of the brain areas involved in the MI network. To this goal, brain activity was recorded using high-density electroencephalography in nineteen healthy adults while visually imagining walking on a straight path. We extracted Event-Related Desynchronizations (ERDs) in the θ, α, and ß band, and we measured MI ability via (i) the Kinesthetic and Visual Imagery Questionnaire (KVIQ), (ii) the Vividness of Movement Imagery Questionnaire-2 (VMIQ), and (iii) the Imagery Ability (IA) score. We then used Pearson's and Spearman's coefficients to correlate MI ability scores and average ERD power (avgERD). Positive correlations were identified between VMIQ and avgERD of the middle cingulum in the ß band and with avgERD of the left insula, right precentral area, and right middle occipital region in the θ band. Stronger activation of the MI network was related to better scores of MI ability evaluations, supporting the importance of testing MI ability during MI protocols. This result will help to understand MI mechanisms and develop personalized MI treatments for patients with neurological dysfunctions.

Are Motor Imagery Ability scores related to cortical activity during gait imagery?

Motor imagery (MI) is the mental execution of actions without overt movements that depends on the ability to imagine. We explored whether this ability could be related to the cortical activity of the brain areas involved in the MI network. To this goal, brain activity was recorded using high-density electroencephalography (hdEEG) in nineteen healthy adults while visually imagining walking on a straight path. We extracted Event-Related Desynchronizations (ERDs) in the ß band, and we measured MI ability via (i) the Kinesthetic and Visual Imagery Questionnaire (KVIQ), (ii) the Vividness of Movement Imagery Questionnaire-2 (VMIQ), and (iii) the Imagery Ability (IA) score. We then used Pearson's and Spearman's coefficients to correlate MI ability scores and average ERD power (avgERD). VMIQ was positively correlated with avgERD of frontal and cingulate areas, whereas IA SCORE was positively correlated with avgERD of left inferior frontal and superior temporal regions. Stronger activation of the MI network was related to better scores of MI ability evaluations, supporting the importance of testing MI ability during MI protocols. This result will help to understand MI mechanisms and develop personalized MI treatments for patients with neurological dysfunctions.

Relationship between Corticospinal Excitability While Gazing at the Mirror and Motor Imagery Ability.

Mirror therapy (MT) helps stroke survivors recover motor function. Previous studies have reported that an individual's motor imagery ability is related to the areas of brain activity during motor imagery and the effectiveness of motor imagery training. However, the relationship between MT and motor imagery ability and between corticospinal tract excitability during mirror gazing, an important component of MT, and motor imagery ability is unclear. This study determined whether the motor-evoked potential (MEP) amplitude while gazing at the mirror relates to participants' motor imagery abilities. Twenty-four healthy right-handed adults (seven males) were recruited. Transcranial magnetic stimulation was performed while gazing at the mirror, and MEP of the first dorsal interosseous muscle of the right hand were measured. Motor imagery ability was measured using the Kinesthetic and Visual Imagery Questionnaire (KVIQ), which assesses the vividness of motor imagery ability. Additionally, a mental chronometry (MC) task was used to assess time aspects. The results showed a significant moderate correlation between changes in MEP amplitude values while gazing at the mirror, as compared with resting conditions, and assessment scores of KVIQ. This study shows that corticospinal excitability because of mirror gazing may be related to the vividness of motor imagery ability.

Corticospinal Excitability of the Lower Limb Muscles During the Anticipatory Postural Adjustments: A TMS Study During Dart Throwing.

Objective: To investigate whether the changes in the corticospinal excitability contribute to the anticipatory postural adjustments (APAs) in the lower limb muscles when performing the ballistic upper limb movement of the dart throwing. Methods: We examined the primary motor cortex (M1) excitability of the lower limb muscles [tibialis anterior (TA) and soleus (SOL) muscles] during the APA phase by using transcranial magnetic stimulation (TMS) in the healthy volunteers. The surface electromyography (EMG) of anterior deltoid, triceps brachii, biceps brachii, TA, and SOL muscles was recorded and the motor evoked potential (MEP) to TMS was recorded in the TA muscle along with the SOL muscle. TMS at the hotspot of the TA muscle was applied at the timings immediately prior to the TA onset. The kinematic parameters including the three-dimensional motion analysis and center of pressure (COP) during the dart throwing were also assessed. Results: The changes in COP and EMG of the TA muscle occurred preceding the dart throwing, which involved a slight elbow flexion followed by an extension. The correlation analysis revealed that the onset of the TA muscle was related to the COP change and the elbow joint flexion. The MEP amplitude in the TA muscle, but not that in the SOL muscle, significantly increased immediately prior to the EMG burst (100, 50, and 0 ms prior to the TA onset). Conclusion: Our findings demonstrate that the corticospinal excitability of the TA muscle increases prior to the ballistic upper limb movement of the dart throwing, suggesting that the corticospinal pathway contributes to the APA in the lower limb in a muscle-specific manner.

Implicit learning of symmetry of human movement and gray matter density: Evidence against pure domain general and pure domain specific theories of implicit learning.

Theories of the neural basis of implicit learning postulated that specific regions were responsible for specific structures (e.g., supra-finite state) regardless of domain (e.g., vision, movement); others assumed that implicit learning was the adaptation that occurred within neural regions dealing with each domain. We explored whether people could implicitly learn to detect symmetry in biological motion, and if so, based on voxel-based morphometry (VBM), whether the learning was associated with language-related regions involved with supra-finite state grammars (such as symmetry) or motor-related regions. To explore the relevance of motor-related regions, we investigated brain structural changes in athletes compared with non-athletes and the advantage of athletes in implicit learning of action symmetry. Further, we examined whether motor imagery ability could account for the role of motor-related regions in this learning. Participants passively observed and memorized a number of biological motion sequences instantiating a symmetry rule and then judged new sequences as grammatical or not. Behaviorally, the implicit acquisition of symmetry could extend to process biological motion. Athletes showed superior classification accuracy and kinesthetic imagery ability, and gave more familiarity attributions. VBM results showed that athletes exhibited greater gray matter density in the right cerebellum, as well as the left lingual gyrus, the left precuneus, the left calcarine gyrus, and the right thalamus. Correlation analysis showed that the cerebellar gray matter density was positively associated with classification accuracy, which was mediated by kinesthetic imagery ability. Moreover, gray matter density of the left inferior frontal cortex was also positively associated with classification accuracy, indicating the involvement of regions related to symmetry learning across domains. The study provides initial evidence that implicit learning involves both adaptation within brain regions responsible for the specific domain as well as brain regions processing the same structure across domains, at least in a case of supra-finite state grammars.

Task-independent Electrophysiological Correlates of Motor Imagery Ability from Kinaesthetic and Visual Perspectives.

Motor imagery (MI) ability is highly subjective, as indicated by the individual scores of the MIQ-3 questionnaire, and poor imagers compensate for the difficulty in performing MI with larger cerebral activations, as demonstrated by MI studies involving hands/limbs. In order to identify general, task-independent MI ability correlates, 16 volunteers were stratified with MIQ-3. The scores in the kinaesthetic (K) and 1st-person visual (V) perspectives were associated with EEG patterns obtained during K-MI and V-MI of the same complex MIQ-3 movements during these MI tasks (Spearman's correlation, significance at <0.05, SnPM corrected). EEG measures were relative to rest (relaxation, closed eyes), and based on six electrode clusters both for band spectral content and connectivity (Granger causality). Lower K-MI ability was associated with greater theta decreases during tasks in fronto-central clusters and greater inward information flow to prefrontal clusters for theta, high alpha and beta bands. On the other hand, power band relative decreases were associated with V-MI ability in fronto-central clusters for low alpha and left fronto-central and both centro-parietal clusters for beta bands. The results thus suggest different computational mechanisms for MI-V and MI-K. The association between low alpha/beta desynchronization and V-MIQ scores and between theta changes and K-MIQ scores suggest a cognitive effort with greater cerebral activation in participants with lower V-MI ability. The association between information flow to prefrontal hub and K-MI ability suggest the need for a continuous update of information to support MI-related executive functions in subjects with poor K-MI ability.

Motor imagery ability assessments in four disciplines: protocol for a systematic review.

INTRODUCTION: Motor imagery (MI) is a very popular and well-accepted technique in different disciplines. Originating from sport and psychology, MI is now also used in the field of medicine and education. Several studies confirmed the benefits of MI to facilitate motor learning and skill acquisition. The findings indicated that individual's MI ability might influence the effectiveness of MI interventions. Over the last two centuries, researchers have developed several assessments to evaluate MI's abstract construct. However, no systematic reviews (SR) exist for MI ability evaluation methods and their measurement properties. METHODS AND ANALYSIS: The SR will evaluate available MI ability assessments and their psychometric properties in four relevant disciplines: sports, psychology, medicine and education. This involves performing searches in SPORTDiscus, PsycINFO, Cochrane Library, Scopus, Web of Science and ERIC. Working independently, two reviewers will screen articles for selection. Then all raw information will be compiled in an overview table-including the articles' characteristics (eg, a study's setting or the population demographics) and the MI ability assessment (psychometric properties). To evaluate the articles' methodological quality, we will use the COSMIN checklist. Then we will evaluate all the included assessments' quality and perform a best-evidence synthesis. Results of this review will be reported following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. ETHICS AND DISSEMINATION: The SR is based on published data, and ethical approval is not required. This review will provide information on assessment performance and equipment, as well as its main focus and usefulness. Furthermore, we will present the methodological quality of all the included articles and assess the included instruments' quality. Ultimately, this will act as a valuable resource, providing an overview of MI ability assessments for individual clinical settings, treatment aims, and various populations. The SR's final report will be published in a peer-reviewed journal and presented at relevant conferences. PROSPERO REGISTRATION NUMBER: CRD42017077004.

Effect of motor imagery therapy on hand function and motor imagery ability of patients after stroke / 中国康复理论与实践

ObjectiveTo observe the effect of motor imagery therapy on hand function and motor imagery ability of stroke patients. MethodsFrom March, 2018 to March, 2020, 41 stroke patients in Beijing Bo'ai Hospital were selected and randomly divided into control group (n = 20) and observation group (n = 21). Both groups received conventional rehabilitation training, and the observation group received motor imagery therapy in addition, for four weeks. Before and after training, the scores of Fugl-Meyer Assessment-Hand (FMA-H) and Kinesthetic and Visual Imagery Questionnaire-10 (KVIQ-10), and the accuracy of mental rotation task were compared between two groups. ResultsOne patient in the observation group dropped down. Before training, there was no significant difference in the scores of FMA-H and KVIQ, and the accuracy of mental rotation task between two groups (P > 0.05). After training, all the indexes improved in both groups (t > 6.611, P < 0.001), and the scores of FMA-H (t = 3.742, P < 0.001) and KVIQ (t = 4.122, P < 0.001), and the accuracy of mental rotation task (t = 2.075, P < 0.05) were higher in the observation group than in the control group. ConclusionMotor imagery therapy could facilliate the recovery of hand dysfunction and improve the motor imagery ability of stroke patients.

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.

The Short-term and Long-term Effect of Motor Imagery Training of Athletes on Their Visual Imagery and Kinesthetic Imagery / 中国运动医学杂志

Objective To investigate the short-term and long-term effect of motor imagery training on visual imagery and kinesthetic imagery of athletes.Methods Twenty athletes majoring in the sports training of Capital University of Physical Education were selected into the experimental group,while 20 counterparts majoring in the human kinetic science were selected into the control group.All subjects received motor imagery training,and were assessed their visual imagery and kinesthetic imagery at three before the training,as well as ten minutes and 48 hours after the training.Results The repetitive measurement and analysis of variance showed that the visual imagery and kinesthetic imagery scores had the main effect of time factor [FvI (2,37)=7.57,P＜0.01;FK1 (2,37)=ll.75,P＜0.01)],as the scores were the highest at ten minutes after training,the second highest at 48 hours after training and the lowest before training.The visual imaginary scores increased significantly after the training,but had no significant difference 48 hours after the training compared to that before the training.After the training the kinesthetic imagery scores increased significantly and then declined slowly,and there were significant differences in the score before and 48 hours after the training (P=0.009).The experimental group and the control group had the same change trend in the visual and kinesthetic imagery scores.The average scores of the former group were higher than the latter at the same time points but without significant differences.The visual and kinesthetic imagery scores had no main effect of group factor,and there was no interaction effect of time factor and group factor.Conclusion Motor imagery training could increase the ability of visual and kinesthetic imagery of people never participating in motor imagery training and the short-term effect was more obvious.The long term effect of motor imagery training was more significant on kinesthetic imagery than visual imagery.

The reliability of the Chinese version of the kinesthetic and visual imagery questionnaire among stroke patients / 中华物理医学与康复杂志

Objective To develop kinesthetic and visual imagery questionnaires applicable to Chinese stroke survivors and evaluate their test-retest reliability,inter-rater reliability and internal consistency.Methods The English version of a kinesthetic and visual imagery questionnaire (KVIQ) was translated into Chinese using wellaccepted questionnaire translation procedures.Thirty stroke survivors were each assessed twice using two versions of the translation (the KVIQ-20 and the KVIQ-10) by two experienced raters with an interval of 7 days between the tests.The test-retest reliability,inter-rater reliability and internal consistency of the visual imagery score (visual imagery subscale),the kinesthetic imagery score (kinesthetic imagery subscale) and the total scores for the KVIQ-20 and KVIQ-10 versions were analyzed.Results The test-retest coefficients,the inter-rater reliability correlation coefficients and Cronbach's alphas for the KVIQ-20 version ranged from 0.879 to 0.945,from 0.894 to 0.936 and from 0.867 to 0.919,respectively.The corresponding measurements for the KVIQ-10 vcrsion were 0.914 to 0.953,0.852 to 0.900 and 0.827 to 0.878.Conclusion Both the KVIQ-20 and KVIQ-10 Chinese instruments have shown good testretest and inter-rater reliability and good internal consistency in assessing stroke survivors.Either is an effective tool for assessing their motor imagery ability.