Mirror Therapy Combined With Contralaterally Controlled Functional Electrical Stimulation for Peripheral Nerve Injury

The goal of this trial is to evaluate the effects of mirror therapy combined with contralaterally controlled functional electrical stimulation on motor recovery and neuroplasticity in patients with peripheral nerve injury. The main questions it aims to answer are:

Question 1: To compare corticomuscular coherence between the groups of mirror therapy combined with contralaterally controlled functional electrical stimulation, sham mirror therapy combined with contralaterally controlled functional electrical stimulation, and control group.

Question 2: To compare sensorimotor recovery between the groups of mirror therapy combined with contralaterally controlled functional electrical stimulation, sham mirror therapy combined with contralaterally controlled functional electrical stimulation, and control group.

Question 3: To evaluate the effects of each intervention on corticomuscular coherence and sensorimotor recovery 12 weeks post-intervention.

Eligible participants will be randomized into three groups:

MT and CCFES group: mirror therapy combined with contralaterally controlled functional electrical stimulation Sham MT and CCFES group: Sham mirror therapy combined with contralaterally controlled functional electrical stimulation Control group: conventional physiotherapy.

Each participant will receive conventional physiotherapy for 50 minutes daily, twice a week for 12 weeks. Conventional physiotherapy includes scar management, joint range of motion exercise, strengthening, stretching, and functional training. Participants in the MT and CCFES group or Sham MT and CCFES group will receive 30 minutes daily, twice a week of the intervention for 12 weeks in addition to the conventional physiotherapy. In the MT and CCFES group, the participants will sit in front of the mirror and watch the mirror reflection of the unaffected hands. At the same time, contralaterally controlled electrical stimulation will be conducted to make the affected hands move with the unaffected hands. The participants in the Sham MT and CCFES group will sit in front of the mirror without mirror reflection, but doing the exercise with contralaterally controlled functional electrical stimulation. All participants will receive the evaluations at baseline and 12 weeks after the intervention. The evaluations include:

Electroencephalography of α and β bands from the sensorimotor cortices will be recorded.

Electromyography will be performed during maximum isometric pinch or lateral pinch strength measurements.

Maximum isometric grip strength, tip pinch strength, lateral pinch strength, sensation tests, and upper extremity function will be measured.

Inclusion criteria

• newly diagnosed median or ulnar nerve transection injury of the forearm in the past 6 months
• sufficient communication in the Chinese language
• being able to follow instructions
• the presence of target muscle denervation (e.g. muscle atrophy, inability to actively contract)
• less than 10% surface EMG activity during pinch evaluation compared to the unaffected side

Exclusion criteria

• had central nervous disease
• had a recent (1 year) history of nerve entrapment syndrome
• had a history of latent neuropathy, such as diabetes or dialysis