CRITICALLY APPRAISED PAPER (CAP) Wu, C., Huang, P., Chen, Y., Lin, K., & Yang, H. (2013). Effects of mirror therapy on motor and sensory recovery in chronic stroke: A randomized controlled trial. Archives of Physical Medicine and Rehabilitation, 94(6), 1023 1030. http://dx.doi.org/10.1016/j.apmr.2013.02.007 CLINICAL BOTTOM LINE: In mirror therapy, the client s affected limb is concealed, while a mirror produces a reflection of the unaffected limb taking the place of the concealed affected limb. The client is instructed to watch the reflection as if it were his or her affected limb. While looking at this reflection, the client performs tasks with the unaffected limb, which makes it look as though the affected limb, too, is performing these tasks. The results of this study show mirror therapy to be effective in improving motor performance, motor control, and temperature sensation in the affected upper extremity of individuals with chronic stroke (more than 6 months from onset). Participants in the mirror therapy group did not have significant differences in activities of daily living performance compared with the participants in the control treatment group. The limitations of this study include small sample size, poor generalizability to all stroke patients, lack of definition of the setting from which participants were selected, failure to assess the extent to which participants focused on the mirror image during the task practice, failure to report the setting of intervention implementation, and a high number of participants lost to 6- month follow-up. The researchers randomly allocated participants to the exposure or control group, defined their inclusion and exclusion criteria well, defined the interventions (except for the location) well, blinded the assessors, and thoroughly described the measures used. If an occupational therapist chooses to implement mirror therapy as an intervention technique, it is relatively low cost and simple. Mirror therapy can be incorporated into occupational therapy services for individuals with chronic stroke and hemiparesis to help improve motor performance, motor control, and temperature sensation in the affected upper extremity; however, further interventions should address performance of activities of daily living. RESEARCH OBJECTIVE(S) List study objectives. To examine the effects of mirror therapy on motor and sensory recovery, in particular motor performance, motor control strategies, sensory recovery, and daily function DESIGN TYPE AND LEVEL OF EVIDENCE: Level I: Randomized controlled trial using a pretest posttest design with an additional 6-1
month follow-up measure SAMPLE SELECTION How were subjects recruited and selected to participate? Please describe. Participants were outpatients with chronic stroke recruited from four hospitals; locations of the hospitals were not reported, but given author affiliations, one can speculate that they were located in Taiwan. A total of 262 individuals were screened for eligibility; of those, 55 met eligibility criteria, but only 33 chose to participate in the study. The exact sampling method was not reported. Inclusion Criteria First ischemic or hemorrhagic stroke occurred more than 6 months ago Upper extremity motor impairment (mild to moderate) Joints in the involved extremity with mild spasticity Cognitively capable of following instructions Exclusion Criteria Participated in another rehabilitative research study in the last 6 months Severe vision or visual perception deficits Serious disease of neuropsychologic, neuromuscular, or orthopedic origin SAMPLE CHARACTERISTICS N= (Number of participants taking part in the study) 33 #/ (%) Male 23/(69.7%) #/ (%) Female 10/(30.3%) Ethnicity NR Disease/disability diagnosis Unilateral ischemic or hemorrhagic cerebrovascular accident INTERVENTION(S) AND CONTROL GROUPS Add groups if necessary Group 1: Mirror therapy Brief description of the intervention The intervention was provided during regularly scheduled occupational therapy sessions. Other interdisciplinary rehabilitation continued without modifications. Each occupational therapy session consisted of 60 min of mirror therapy followed by 30 min of taskoriented functional practice. During the mirror therapy intervention, participants watched the reflection of their unaffected limb as if it were the affected limb while performing gross and fine motor tasks. 2
How many participants in the group? Where did the intervention take place? Who Delivered? How often? For how long? 16 NR Certified occupational therapist trained to follow treatment protocol 90 min per day, 5 days per week 4 weeks Group 2: Control treatment Brief description of the intervention How many participants in the group? Where did the intervention take place? Who Delivered? How often? For how long? The control treatment session consisted entirely of task-oriented therapeutic activities. Functional tasks were chosen according to the abilities of the participants. The control treatment focused on motor control, coordination, fine motor skills, static and dynamic standing and sitting, balance, and compensatory strategies. Other interdisciplinary rehabilitation continued without modifications. 17 NR Certified occupational therapist trained to follow treatment protocol 90 min per day, 5 days per week 4 weeks Intervention Biases: Check yes, no, or NR and explain, if needed. Contamination: NR Comment: Contamination of the treatment and control groups is not discussed. Co-intervention: Comment: Both groups continued with their other interdisciplinary rehabilitation services; whether all participants were receiving interdisciplinary rehabilitation or even the same types of services is not reported. Timing: 3
Site: NR NR Comment: Comment: The site of the mirror therapy or control treatment interventions is not reported. Use of different therapists to provide intervention: Comment: Five certified occupational therapists carried out the treatment protocol; whether these therapists conducted both the control and the mirror therapy treatments or were only responsible for one of the treatments is not specified. The article does not state whether the participants interacted with the same occupational therapist at each treatment session. MEASURES AND OUTCOMES Complete for each measure relevant to occupational therapy: Measure 1: Name/type of Fugl Meyer Assessment (FMA) Sensorimotor function of the affected upper extremity (only the upper extremity motor function items were used) NR When is the Pretreatment and posttreatment Measure 2: Name/type of When is the VICON MX a Reaction time, normalized movement time, normalized total displacement, joint recruitments, and maximum shoulder and elbow crosscorrelation of the affected upper extremity NR NR Pretreatment and posttreatment 4
Measure 3: Name/type of When is the Measure 4: Name/type of When is the Measure 5: Name/type of When is the Revised Nottingham Sensory Assessment Sensory function of affected upper extremity (only the Tactile subtest was used) NR Pretreatment and posttreatment Motor Activity Log Activities of daily living function Pretreatment, posttreatment, and 6-month follow-up ABILHAND questionnaire Activities of daily living function Pretreatment, posttreatment, and 6-month follow-up Measurement Biases Were the evaluators blind to treatment status? Check yes, no, or NR, and if no, explain. Comment: The evaluators were two certified occupational therapists blinded to group allocation of participants. Recall or memory bias. Check yes, no, or NR, and if yes, explain. 5
NO Comment: RESULTS List key findings based on study objectives Include statistical significance where appropriate (p<0.05) Include effect size if reported The researchers reported significant and large to moderate effects favoring the mirror therapy group on the FMA total (p =.009, η 2 =.17) and the distal part scores of the FMA (p =.041, η 2 =.10). Nonsignificant but moderate to large positive effects favoring the mirror therapy group were found on the overall Tactile scores of the Revised Nottingham Sensory Assessment measuring sensory function. The subscale scores showed a significant and large effect favoring the mirror therapy group on temperature sensory recovery (p =.040, η 2 =.25). Scores on the Motor Activity Log did not show any significant differences between the mirror therapy and control treatment groups at posttreatment or at follow-up. No significant differences between the mirror therapy and control treatment groups on the ABILHAND questionnaire were found at posttreatment or at follow-up. Therefore, the researchers reported no significant differences in activities of daily living performance between the mirror therapy and control treatment groups at posttreatment or follow-up. The researchers did not include the 12 participants lost to the 6-month follow-up in their follow-up analysis. Was this study adequately powered (large enough to show a difference)? Check yes, no, or NR, and if no, explain. NO Comment: The researchers only conducted a post hoc power analysis for the Tactile subtest of the Revised Nottingham Sensory Assessment. The results show that there was a 30% chance of detecting a group difference with a Type I error of.05. The researchers suggested recruiting 26 participants into each group in the future to increase the chance to 80%. Power analyses were not conducted for the remaining measures. Were appropriate analytic methods used? Check yes, no, or NR, and if no, explain. NO Comment: The researchers used one-tailed tests, only looking for positive effects of mirror therapy. This limits the study s ability to detect whether the control treatment group had better results than the mirror therapy group. Were statistics appropriately reported (in written or table format)? Check yes or no, and if no, explain. Comment: 6
Was the percent/number of subjects/participants who dropped out of the study reported? Limitations: What are the overall study limitations? This study had a small sample size, which limits the power. The researchers did not specify where the study sample was selected from, nor did they specify where the intervention and control treatments were administered. This decreases the ability to duplicate the study or incorporate the intervention into practice. Because of the inclusion and exclusion criteria, the results of the study are only applicable to individuals with mild to moderate motor impairment at the chronic stage after stroke onset, which reduces the generalizability of the study to all stroke patients or other nonstroke patients with upper extremity motor impairments. A large number of participants (12) were lost to the 6-month follow-up; this hindered the researchers from making solid conclusions about the lasting effects of mirror therapy. CONCLUSIONS State the authors conclusions related to the research objectives. The researchers concluded that mirror therapy after stroke resulted in enhanced effects on movement performance, motor control, and temperature sensation recovery in comparison with the control treatment; however, they could not deduce that mirror therapy had better effects than the control treatment on activities of daily living performance. This finding contradicts some of the existing research, and the researchers suggested that because their participants were outpatients living at home, they might already have had an established, stable activities of daily living routine, which might be less likely to change than the routines of people living in rehabilitation centers. On the basis of the positive effects of mirror therapy that were found, the researchers speculated that cortical reorganization might have occurred as a result of mirror therapy. They found it interesting that those in the mirror therapy group scored better on the distal part of the FMA, in comparison with the proximal part, and hypothesized that mirror therapy may be more associated with motor recovery in the distal parts of the body. Joint recruitments and movement time did not improve significantly more in the mirror therapy group than in the control treatment group. The researchers suggested that this could have been because they did not stress movement speed in their treatment protocols or because the task was not challenging enough to detect gained joint ranges, if any, after the intervention. The significant improvements in temperature sensation in the mirror therapy group versus the control group could be explained by multimodal neurons, according to the researchers. These multimodal neurons respond to sensory and movement stimuli, so the visual illusion perceived during mirror therapy may provide sensory input that modulates the somatosensory cortex, contributing to the recovery of somatosensation. As stated by the researchers, the results of the study are difficult to generalize because of its small sample size and inclusion of only participants who had mild to moderate impairments and were living at home. The researchers suggested future research be done with a larger sample size with varying characteristics. 7
This work is based on the evidence-based literature review completed by Laura Cox, OTS, and Ashley Halle, OTD, OTR/L, faculty advisor, University of Southern California. CAP Worksheet adapted from Critical Review Form Quantitative Studies. Copyright 1998 by M. Law, D. Stewart, N. Pollack, L. Letts, J. Bosch, and M. Westmorland, McMaster University. Used with permission. 8