Effect Of Mirror Visual Feedback Research Articles

The Effect of Mirror Visual Feedback on Spatial Neglect for Patients after Stroke: A Preliminary Randomized Controlled Trial.

We investigated the effects of mirror visual feedback (MVF), with reference to using a glass wall or a covered mirror, on the reduction of spatial neglect for patients with stroke. A total of 21 subacute patients with left spatial neglect after right-hemispheric stroke were randomly assigned to 3 groups: MVF, sham 1 (viewing the hemiparetic arm through the transparent glass during bilateral arm movement) and sham 2 (using a covered mirror). The 3-week treatment program for all groups consisted of 12 sessions of movement tasks for the hemiparetic arm graded according to the severity of arm impairments. Blinded assessments were administered at pre/post and a three-week follow-up. The results showed that there was no significant advantage for MVF than sham 1; however, MVF was more beneficial than sham 2, as shown by the line crossing (p = 0.022). Improvement in discriminating the left-gap figures on the left and right side of the page in the Gap Detection Test was greater in MVF than using the covered mirror (p = 0.013; p = 0.010), showing a slight advantage of MVF in alleviating allocentric symptoms. Our study confirms that MVF was superior to using a covered mirror as a method for reducing spatial neglect and in alleviating its allocentric symptoms, but no significant advantage over bilateral arm movement through transparent glass was found. Further research in comparing their therapeutic effects is warranted.

Modulation of Functional Connectivity in Response to Mirror Visual Feedback in Stroke Survivors: An MEG Study.

Background. Several brain regions are activated in response to mirror visual feedback (MVF). However, less is known about how these brain areas and their connectivity are modulated in stroke patients. This study aimed to explore the effects of MVF on brain functional connectivity in stroke patients. Materials and Methods. We enrolled 15 stroke patients who executed Bilateral-No mirror, Bilateral-Mirror, and Unilateral-Mirror conditions. The coherence values among five brain regions of interest in four different frequency bands were calculated from magnetoencephalographic signals. We examined the differences in functional connectivity of each two brain areas between the Bilateral-No mirror and Bilateral-Mirror conditions and between the Bilateral-Mirror and Unilateral-Mirror conditions. Results. The functional connectivity analyses revealed significantly stronger connectivity between the posterior cingulate cortex and primary motor cortex in the beta band (adjusted p = 0.04) and possibly stronger connectivity between the precuneus and primary visual cortex in the theta band (adjusted p = 0.08) in the Bilateral-Mirror condition than those in the Bilateral-No mirror condition. However, the comparisons between the Bilateral-Mirror and Unilateral-Mirror conditions revealed no significant differences in cortical coherence in all frequency bands. Conclusions. Providing MVF to stroke patients may modulate the lesioned primary motor cortex through visuospatial and attentional cortical networks.

The Priming Effects of Mirror Visual Feedback on Bilateral Task Practice: A Randomized Controlled Study.

The priming effect of mirror visual feedback can be simply provided by inexpensive mirror therapy (MT), which exhibits beneficial effects on sensorimotor recovery in stroke. The present study was a single-blind pretest-posttest study that examined whether the priming effect of mirror visual feedback on bilateral task practice would render better outcomes. Twenty-three patients with chronic stroke were randomized to receive hospital-based task-oriented MT or bilateral arm training (BAT) for 4 weeks at 90 minutes/day, 3 days/week and a home practice for 30-40 minutes/day, 5 days/week. There was the potential trend for MT to improve temperature sense as measured by the revised Nottingham Sensory Assessment (Cohen's d = 1.00; 95% confidence interval, -0.09 to 2.09), and MT increased the Stroke Impact Scale 3.0 total score (d = 0.89; 0.003 to 1.71). MT also showed a trend for greater improvements in the Motor Activity Log (amount of use: d = 0.62; -0.24 to 1.44; quality of movement: d = 0.50; -0.35 to 1.31). MT involving bilateral movement practice with the priming effect of mirror visual feedback may render beneficial effects. The unilateral approach or MT augmented by extra feedback might be appropriate modifications.

The effect of early intervention of mirror visual feedback on pain, disability and motor function following hand reconstructive surgery: a randomized clinical trial

Objective: To determine the effect of mirror visual feedback (MVF) on disability, pain, and motor function on patients who underwent hand reconstructive surgery. Design: Randomized, single-blinded controlled trial. Setting: Rehabilitation center. Subjects: A total of 40 patients who were randomly assigned into the intervention group (n = 20) and control group (n = 20) participated in this study. Interventions: The rehabilitation sessions took place twice a week for eight weeks. The control group received traditional rehabilitation for 75 minutes. While the intervention group performed MVF and traditional rehabilitation for 30 and 45 minutes, respectively. Measures: Pain and disability of the hand were assessed with McGill pain questionnaire and Disability of Arm, Shoulder, and Hand (DASH) scores. The range of joint motion was evaluated by Goniometer, and the strength of grip and pinch was evaluated by Dynamometer and Pinch gauge and dexterity evaluated by Minnesota Manual Muscle test. Results: The results indicated that both traditional and MVF methods induced significant decreasing pain (Pain Rate Index: F = 68.48, P = 0.000; Number of Word Count: F = 70.96, P = 0.000), disability (F = 50.08, P = 0.000) and increasing dexterity (placing test: F = 28.73, P = 0.000), and range of motion (F = 33.16, P = 0.000). The results also showed that the positive effect of MVF on pain, disability, dexterity, and range of motion was significantly greater than that of controls (P < 0.05), but there was no significant result in grip and lateral pinch strength between the intervention and control group (P > 0.05). Conclusion: MVF, in conjunction with traditional rehabilitation programs, may lead to greater improvements in pain, disability, placing dexterity, and range of motion. But it seems not to be effective on pinch and grip power and turning dexterity.

Can mirror visual feedback improve sensory relearning outcomes following median/ulnar nerve repair?

Background/Aims: Mirror visual feedback is an intervention that focuses on watching the movements of the intact hand in the mirror to restore the movements of the injured hand. This method is developed based on the concept of the central reflection of the amputated or injured limb. This study aims to determine the effect of mirror visual feedback as a complementary method on the outcomes of sensory relearning in patients following median/ulnar nerve repair. Methods: This randomised clinical trial was conducted on 20 patients with median/ulnar nerve damage who were selected through convenience sampling and were then randomly assigned to a treatment and a control group. Both groups received traditional rehabilitation in three 40-minute sessions a week. In addition, the treatment group received mirror visual feedback 15 minutes a day, 5 days a week, for 8 weeks. The patients' sensory status was assessed using Semmes-Weinstein Monofilaments and two-point discrimination tests and their sensory function was assessed using stereognosis both before and after the intervention. Findings: The final analysis was performed on a total of 20 patients. The Semmes-Weinstein Monofilaments test and two-point discrimination scores obtained showed significant improvements following therapy in both groups. The changes in Semmes-Weinstein Monofilaments test (P=0.000], two-point discrimination (P=0.000) and stereognosis (active: P=0.001, passive: P=0.000) scores were significantly greater in the mirror therapy group compared to the controls. Conclusions: Mirror visual feedback in conjunction with traditional sensory retraining programmes led to greater improvements in superficial sensation and touch discrimination of the hand in the first phase of the sensory relearning programme. This may be due to the use of the neuroplasticity potential, the stimulation of the somatosensory areas and motor networks, the adjustment of early cortical reorganisation and the prevention of further changes.

Neurophysiological effects of mirror visual feedback in stroke patients with unilateral hemispheric damage

Background and ObjectiveMirror visual feedback (MVF; the illusory perception of movement in one hand upon viewing the moving opposite hand in a midsagittal mirror) is thought to facilitate restoration of mal-adaptive neurophysiological processes underlying conditions like complex regional pain syndrome and phantom limb pain, and to have a positive effect on brain plasticity processes underlying motor recovery after stroke. However, its exact mode of action remains unclear. The aim of the current study was to explore the immediate neurophysiological effects of MVF in patients with stroke-related hemiparesis. We also investigated how these effects relate to lesion location and extent. MethodEEG and EMG data were obtained from 14 first-event sub-acute stroke patients (8 with right-, 6 with left-hemiparesis) during repeated wrist extension movements of the Non-paretic Upper-Limb (NUL), without (NUL/M-) and with (NUL/M+) a midsagittal mirror, as well as during bilateral movements with a mirror (Bil/M+). EEG data was correlated with normalized lesion data obtained from follow-up CT scans. ResultsNUL movement was accompanied by an asymmetric event-related de-synchronization (ERD) of low-beta EEG oscillations, with a more conspicuous ERD in the non-affected hemisphere. In the mirror condition, ERD magnitude was attenuated in both hemispheres. Stronger attenuation in the non-affected hemisphere abolished the hemispheric asymmetry. ERD attenuation by the mirror was affected by lesion side, the severity of hemiparesis and by lesion location and extent. ConclusionFollowing hemispheric stroke, the magnitude of low-beta ERD accompanying unilateral movement of the non-involved upper limb, and its hemispheric asymmetry, are both reduced by MVF. Low-beta ERD dynamics may serve as a marker of neurophysiological response to MVF in research aimed to elucidate the factors influencing patients’ clinical gain from this treatment.

Effect of Mirror Visual Feedback on Upper Extremity Function and Wrist Proprioception in Cerebral Palsy Children with Hemiparesis

The function of the affected side in the hemiplegic cerebral palsy is influenced by muscle tone abnormality, change of proprioception, diminished power, and decreased the speed of movement, weak grasp, and release functions. Mirror therapy (MT) is a therapeutic technique that uses the interaction of visuomotor-proprioception inputs to improve movement performance of the affected limb. This study was done to investigate the effects of mirror visual feedback exercises on upper extremity function and on the alternation of wrist proprioception in children with hemiparesis. Thirty-two children with spastic hemiparesis from both sexes ranging in age from five to seven years represented the sample of the study. They were assigned randomly into two groups of equal number (control and study). Every child in both groups was evaluated at baseline and after 3 months of intervention using The Quality of Upper Extremity Skills Test to evaluate movement patterns and hand function. Also, electro-goniometer was used to assess repositioning error through Active Reproduction of Active Positioning test (ARAP). The control group received a selected exercise program, while the study group received mirror visual feedback (MVF) exercises program training in addition to the same exercise program given to control group. Comparison of the pre-treatment results of the two groups revealed no significant differences in all variables, while significant improvements were observed in all the measuring variables of the two groups when comparing their pre and post-treatment mean values. Significant differences were also observed when comparing the post-treatment results of the two groups in favor of the study group. MVF exercises could be used together with a therapeutic exercise program for the enhancement of hand function and wrist proprioception in children with hemiparesis.

Effect of Mirror Visual Feedback on Hand Functions in Children with Hemiparesis

Background: Hemiparetic and hemiplegic cerebral palsy(CP) constitute at least a third of all people with CP. Children with hemiparesis are suffering from weak hand muscles and retarded hand use.Mirror therapy is a relatively new ap proach in rehabilitation used in different neurological disorders. In mirror therapy a mirror is positioned orthogonally in front of the center of the patient’s body. The less-affected (healthy) extremity is moved and observed in the mirror. The purpose of this study was to determine the effect of mirror visual feedback on improving hand functions in chil dren with hemiparesis. Methods: Forty children with hemiparesis of both sexes, ranged in age from five to seven years old, participated in thisstudy. They were divided randomly into two groups of equal number (control and study). The control group re ceived a specially designed physical therapy exercise program for four successive weeks while the study group received mirrorexercise program in addition to the same program of the control group. Hand functions assessments was done usinggrasping and object manipulation subtests of Peabody developmental motor scale (PDMS-2). Hand grip strength was performed using handheld dynamometer. Evaluation was performed pre and post treatment program. Results:There was no significant difference between both groups in the pre-treatment mean values of all measured variables. Also, the results of this study revealed a significant improvement in the scores of the PDMS-2 andin grasp strength of the 2 groups. Post treatment results revealed more improvement in favor of the study group as compared with the control group. Conclusion: Using the mirror visual feedback could help in improving hand functions in children with hemiparesis.

Delayed mirror visual feedback presented using a novel mirror therapy system enhances cortical activation in healthy adults.

BackgroundMirror visual feedback (MVF) generated in mirror therapy (MT) with a physical mirror promotes the recovery of hemiparetic limbs in patients with stroke, but is limited in that it cannot provide an asymmetric mode for bimanual coordination training. Here, we developed a novel MT system that can manipulate the MVF to resolve this issue. The aims of this pilot study were to examine the feasibility of delayed MVF on MT and to establish its effects on cortical activation in order to understand how it can be used for clinical applications in the future.MethodsThree conditions (no MVF, MVF, and 2-s delayed MVF) presented via our digital MT system were evaluated for their time-course effects on cortical activity by event-related desynchronization (ERD) of mu rhythm electroencephalography (EEG) during button presses in 18 healthy adults. Phasic ERD areas, defined as the areas of the relative ERD curve that were below the reference level and within -2–0 s (P0), 0–2 s (P1), and 2–4 s (P2) of the button press, were used.ResultsThe overall (P0 to P2) and phasic ERD areas were higher when MVF was provided compared to when MVF was not provided for all EEG channels (C3, Cz, and C4). Phasic ERD areas in the P2 phase only increased during the delayed-MVF condition. Significant enhancement of cortical activation in the mirror neuron system and an increase in attention to the unseen limb may play major roles in the response to MVF during MT. In comparison to the no MVF condition, the higher phasic ERD areas that were observed during the P1 phase in the delayed-MVF condition indicate that the image of the still hand may have enhanced the cortical activation that occurred in response to the button press.ConclusionsThis study is the first to achieve delayed MVF for upper-limb MT. Our approach confirms previous findings regarding the effects of MVF on cortical activation and contributes additional evidence supporting the use of this method in the future for upper-limb motor training in patients with stroke.Electronic supplementary materialThe online version of this article (doi:10.1186/s12984-015-0053-1) contains supplementary material, which is available to authorized users.

Effects of mirror visual feedback and spinal mobilisations on pain and tactile acuity: a randomised controlled trial

Effects of mirror visual feedback and spinal mobilisations on pain and tactile acuity: a randomised controlled trial

Electrophysiological manifestations of mirror visual feedback during manual movement

ObjectiveTo investigate the neurophysiological manifestations of the mechanism underlying the effects of Mirror Visual Feedback (MVF) during manual movement. MethodThirteen healthy right handed individuals were assessed while performing repeated unilateral wrist extension movements with and without MVF. The effect of MVF on EEG oscillations was studied in 3 distinct frequency ranges (low mu, high mu, low beta). ResultsAnalysis of the low beta range showed that MVF reduces the magnitude of event-related de-synchronization (ERD) in the hemisphere contra-lateral to the moving hand. This effect reached significance when the moving hand was the dominant hand. In the analysis of the low mu range, bi-hemispheric amplification of ERD by the mirror pointed to an added effect of neural recruitment. This effect reached significance when the moving hand was the non-dominant hand. ConclusionsMVF applied during unilateral manual movement (a) attenuates hemispheric activation asymmetry, and (b) is likely to involve recruitment of the mirror neuron system. SignificanceAs each of the above two effects reached significance only in one hand (dominant and non-dominant, respectively), clinical application of MVF might show a different level of efficacy in the treatment of right and left hemiparesis.

Matching accuracy in hemiparetic cerebral palsy during unimanual and bimanual movements with (mirror) visual feedback

In the present study participants with Spastic Hemiparetic Cerebral Palsy (SHCP) were asked to match the position of a target either with the impaired arm only (unimanual condition) or with both arms at the same time (bimanual condition). The target was placed at 4 different locations scaled to the individual maximum reaching distance. To test the effect of mirror visual feedback of the less-impaired arm on the matching accuracy, an opaque screen or a mirror was placed in between the arms which masked vision of the impaired arm. Absolute endpoint error was smaller in the bimanual condition compared to the unimanual condition, but there was no effect of mirror visual feedback. Inspection of the individual data, however, showed that 13 out of 23 participants did experience a positive effect of mirror visual feedback. A positive correlation between the baseline error (screen) and the improvement in accuracy with mirror visual feedback seems to suggest that individuals with lower proprioceptive accuracy in the baseline condition may benefit more from mirror visual feedback. Together these findings indicate that bimanual therapy and therapy with mirror visual feedback might be valuable approaches for rehabilitation for a subset of the individuals with SHCP.

The positive effect of mirror visual feedback on arm control in children with Spastic Hemiparetic Cerebral Palsy is dependent on which arm is viewed

Mirror visual feedback has previously been found to reduce disproportionate interlimb variability and neuromuscular activity in the arm muscles in children with Spastic Hemiparetic Cerebral Palsy (SHCP). The aim of the current study was to determine whether these positive effects are generated by the mirror per se (i.e. the illusory perception of two symmetrically moving limbs, irrespective of which arm generates the mirror visual feedback) or by the visual illusion that the impaired arm has been substituted and appears to move with less jerk and in synchrony with the less-impaired arm (i.e. by mirror visual feedback of the less-impaired arm only). Therefore, we compared the effect of mirror visual feedback from the impaired and the less-impaired upper limb on the bimanual coupling and neuromuscular activity during a bimanual coordination task. Children with SHCP were asked to perform a bimanual symmetrical circular movement in three different visual feedback conditions (i.e. viewing the two arms, viewing only one arm, and viewing one arm and its mirror image), combined with two head orientation conditions (i.e. looking from the impaired and looking from the less-impaired body side). It was found that mirror visual feedback resulted in a reduction in the eccentric activity of the Biceps Brachii Brevis in the impaired limb compared to the condition with actual visual feedback from the two arms. More specifically, this effect was exclusive to mirror visual feedback from the less-impaired arm and absent when mirror visual feedback from the impaired arm was provided. Across conditions, the less-impaired arm was the leading limb, and the nature of this coupling was independent from visual condition or head orientation. Also, mirror visual feedback did not affect the intensity of the mean neuromuscular activity or the muscle activity of the Triceps Brachii Longus. It was concluded that the positive effects of mirror visual feedback in children with SHCP are not just the result of the perception of two symmetrically moving limbs. Instead, in order to induce a decrease in eccentric neuromuscular activity in the impaired limb, mirror visual feedback from the ‘unaffected’ less-impaired limb is required.