Combined transcranial direct current stimulation and mirror therapy for upper limb rehabilitation in patients with stroke: a systematic review and meta-analysis

Clinical Snapshot

Key Findings

• P Value: Upper limb motor function: p = 0.0002; ADL: p < 0.0001; CMCT: p < 0.0001

• Effect Size: Upper limb motor function: SMD = 0.73 (moderate-large); ADL: SMD = 0.84 (large); CMCT: SMD = −1.26 (large); Subacute stroke subgroup: SMD = 1.03 (large)

• Primary Outcome: Upper limb motor function significantly improved with combined tDCS + MT versus control (SMD = 0.73); ADL also significantly improved (SMD = 0.84); CMCT significantly reduced, indicating improved corticospinal conduction efficiency (SMD = −1.26)

• Nnt Or Sensitivity: NNT not calculable from SMD data without raw proportions. Effect sizes interpreted using Cohen's conventions: SMD 0.73–1.26 represents moderate-to-large clinical effects, though clinical meaningfulness relative to established minimal clinically important differences (MCIDs) for tools such as the Fugl-Meyer Assessment or Barthel Index cannot be confirmed without instrument-specific data

• Confidence Interval: Upper limb motor function: 95% CI 0.34 to 1.12; ADL: 95% CI 0.46 to 1.22; CMCT: 95% CI −1.60 to −0.92; Subacute subgroup: 95% CI 0.73 to 1.33

Clinical Application

Both tDCS and mirror therapy are relatively low-cost, non-invasive interventions. tDCS devices are commercially available and portable. Mirror therapy requires minimal equipment. However, combined delivery requires trained physiotherapy staff familiar with both modalities, standardised tDCS protocols, and appropriate patient selection. Implementation in community rehabilitation or outpatient settings is feasible but requires staff training and protocol standardisation. The optimal tDCS parameters (anodal vs. cathodal, electrode placement, current intensity 1–2 mA, session duration) remain to be definitively established. In Australia, tDCS is not currently listed on the Medicare Benefits Schedule (MBS) as a standalone reimbursable intervention for stroke rehabilitation, limiting routine clinical access. Mirror therapy is incorporated into some Australian stroke rehabilitation units as part of task-specific training consistent with RACGP and Stroke Foundation Clinical Guidelines for Stroke Management (2023), which recommend task-specific upper limb training. The Stroke Foundation's 'Clinical Guidelines for Stroke Management' acknowledge emerging evidence for adjunctive neuromodulation but do not yet provide a specific recommendation for combined tDCS+MT. TGA regulatory status of tDCS devices varies; most are classified as Class IIa medical devices. Clinicians in Australian public hospital rehabilitation units may consider this combination within a research or clinical trial framework pending stronger evidence. Private physiotherapy practices may offer tDCS as an adjunct, though PBS subsidy is unavailable. The subacute stroke finding is particularly relevant to Australian inpatient rehabilitation units where patients are typically admitted within days to weeks post-stroke. Adult stroke survivors with upper limb motor impairment, particularly those in the subacute phase (where subgroup SMD = 1.03 suggests greatest benefit). Patients must be cognitively capable of engaging with mirror therapy and have no contraindications to tDCS (e.g., implanted metallic devices, seizure history, skull defects at electrode sites).

Abstract

Upper limb impairment is among the common consequences of stroke. Combining transcranial direct current stimulation (tDCS) and mirror therapy (MT) have recently been used to improve neural plasticity and functional recovery. This review aims to evaluate the effects of combined tDCS and MT on upper limb function in patients with stroke. "PubMed, Scopus, Web of Science, CINAHL, PEDro, and EMBASE" were searched from their inception to March 2026. Randomized controlled trials investigating the combination of tDCS and MT in patients with stroke and assessing upper limb function were included. The quality and the certainty of evidence were evaluated. Seven studies (454 participants) met the eligibility criteria. Significant improvements were demonstrated in upper limb motor function (SMD = 0.73, 95% CI 0.34 to 1.12, p = 0.0002), activities of daily living (SMD = 0.84, 95% CI 0.46 to 1.22, p < 0.0001), and neurophysiological outcomes reflecting corticospinal conduction efficiency, assessed using central motor conduction time (CMCT) (SMD = -1.26, 95% CI -1.60 to -0.92, p < 0.0001). Subgroup analysis demonstrated greater effects in subacute stroke (SMD = 1.03, 95% CI 0.73 to 1.33). Other outcomes reported improvements in hand function and grip strength. Preliminary evidence suggests that combining tDCS and MT may improve upper limb motor and functional outcomes after stroke; however, these findings should be interpreted with caution due to heterogeneity and the limited data. Further studies are strongly needed.

References

1. 1.Alashram, A. R. (2026). Combined transcranial direct current stimulation and mirror therapy for upper limb rehabilitation in patients with stroke: a systematic review and meta-analysis. Neurological Sciences: Official Journal of the Italian Neurological Society and of the Italian Society of Clinical Neurophysiology. Advance online publication. https://pubmed.ncbi.nlm.nih.gov/42429988