Additive effects of mirror therapy and bilateral TENS on upper limb recovery in chronic stroke: a randomized controlled trial.

Objective: To determine whether the addition of mirror therapy to bilateral transcutaneous electrical nerve stimulation (Bi-TENS), a supraspinally acting intervention, yields additional benefits in upper extremity motor recovery after chronic stroke. Methods: Thirty individuals with chronic hemiparesis were randomized to receive either Bi-TENS combined with mirror therapy (n = 15) or Bi-TENS alone (n = 15). In both groups, Bi-TENS was applied bilaterally to the finger extensor muscles for 5 sessions per week over 4 weeks. Upper extremity motor function was assessed using the Fugl-Meyer Assessment for the Upper Extremity (FMA-UE) as the primary outcome measure at baseline, immediately after the intervention, and at a 3-month follow-up. All assessments were conducted by a blinded assessor. Results: Baseline FMA-UE scores were comparable between groups (mirror therapy + Bi-TENS: 44.2 ± 11.1; Bi-TENS alone: 47.1 ± 8.1; p = 0.415). Both intention-to-treat and per-protocol analyses demonstrated significant improvements in FMA-UE scores over time (intention-to-treat: p = 0.001; per-protocol: p < 0.001). However, no significant group-by-time interaction was detected in intention-to-treat or per-protocol analyses (p = 0.799 and p = 0.374, respectively). Conclusion: Both Bi-TENS alone and Bi-TENS combined with mirror therapy yielded comparable improvements in upper extremity motor function in individuals with chronic stroke, suggesting that the addition of mirror therapy did not produce an additive effect under the conditions of the present study. Clinical relevance: The findings indicate that Bi-TENS is an effective adjunctive intervention for upper extremity motor recovery in chronic stroke. Given the comparable outcomes observed with and without mirror therapy, clinicians may consider prioritizing Bi-TENS when treatment duration or therapeutic resources are constrained.