Mirror Therapy Combined With TENS for Motor Recovery in Paretic Upper Limbs of Chronic Stroke Patients

A prospective, single-blind, randomized controlled clinical trial included 30 chronic stroke patients. The patients were assigned to the Mirror group (n=15) and the Control group (n=15) through block randomization.At the end of the three-month follow-up period, 11 patients in the Mirror group and 14 patients in the Control group completed the study. Both groups received conventional rehabilitation therapy for a total of 20 sessions (5 days a week for 4 weeks), along with 30 minutes of transcutaneous electrical nerve stimulation (TENS) applied bilaterally to the finger extensor muscles. In the Mirror group, mirror therapy was additionally administered following the TENS intervention.Upper extremity motor function was assessed by a blinded evaluator using the Fugl-Meyer Assessment for Upper Extremity (FMA-UE) at three time points: baseline, immediately post-treatment (1 month), and at follow-up (2 months after treatment completion).

The effect size (Cohen's d = 0.314) used to calculate the minimum sample size for detecting a significant difference between groups (Bi-TENS + Mirror therapy, Bi-TENS) was obtained from a previous study. (Peiming ve ark. 2021) The sample size was then calculated using the G*Power software version 3.1.9.4 (Franz Faul, University of Kiel, Germany), with an alpha error level of 0.05, a power of 0.95, an inter-correlation of 0.5, and a global non-correlation of 1. The total sample size required for this study was calculated to be 24. Assuming a dropout rate of 20%, the total sample size was determined to be 30.

The normality of the variables was assessed graphically and using the Shapiro-Wilk test. Data that followed a normal distribution were summarized as Mean ± Standard Deviation, while data that did not follow a normal distribution were summarized as Median and the interquartile range (Q1-Q3). Categorical variables were summarized as frequency (percentage). Comparisons of means between groups were performed using the Independent Samples t-test if the data followed a normal distribution, and the Mann-Whitney U test if the data did not follow a normal distribution. For categorical variables, comparisons between groups were made using the Chi-square test or Fisher's Exact test. Intra-group comparisons of means were performed using repeated measures ANOVA. Bonferroni correction was applied for post-hoc pairwise comparisons. A statistical significance level of p < 0.05 was considered. The data were statistically analyzed using the per-protocol approach. Additionally, the intention-to-treat analysis was performed using the Last Observation Carried Forward (LOCF) method. In the LOCF method, missing values are replaced with the last available observation for each participant Statistical analyses and calculations were performed using IBM SPSS Statistics 21.0 (IBM Corp. Released 2012. IBM SPSS Statistics for Windows, Version 21.0. Armonk, NY: IBM Corp.) and MS-Excel 2007.

Inclusion criteria

• Individuals with a history of unilateral stroke
• Cases with a stroke duration of >6 months
• Brunnstrom stage for the upper extremity ≥3
• Brunnstrom stage for the hand ≥4
• Mini-mental test score >21
• Normal vision and hearing functions

Exclusion criteria

• Individuals with aphasia
• Individuals with neglect
• Those with a history of traumatic brain injury
• Individuals with uncontrolled cardiovascular disease
• Active inflammatory rheumatological or infectious diseases
• Individuals with significant upper extremity peripheral neuropathy
• Those with severe sensory deficits
• Individuals with severe shoulder, elbow, wrist, or finger severe spasticity(Modified Ashworth Scale score of 4)
• Individuals with a cardiac pacemaker
• Those with lesions on the skin of the upper extremity
• Individuals with skin allergies