taVNS Combined With TENS on Motor Function in Stroke

The left cymba conchae was selected as taVNS stimulation side. The taVNS was delivered by earphone-shaped stimulators for 30 minutes with the stimulation parameters as follows: 0.3-ms square pulses at 20 Hz for 30 seconds with a duty cycle of 1:1; and the intensity of the stimulation was individually adjusted according to the tolerance of participants

The sham stimulation will be delivered with a shame model of the same device that used in the taVNS intervention. The interference of the device will display that the device is working normally while no electrical current output.

TENS will be delivered with commercial TENS machine. The stimulation parameters were as follows: continuous 0.2-ms square pulses at 100 Hz with the intensity adjusted according to the tolerance of each patient. Disposable surface electrodes of 5X5 cm2 were applied to stimulate the median nerve and the superficial radial nerve of both the affected and non-affected upper limbs. The placebo stimulation was delivered with a device that looked identical but had its internal electrical circuit disconnected.

The sham stimulation will be administered using a device that looks identical to the TENS device used in the TENS intervention. However, the internal electrical circuit of this device will be disconnected.

A physiotherapist supervised the intervention and monitored individual progress. The task-oriented training aims to improve the motor recovery of the upper limbs through the systematic and repetitive movement of shoulder, elbow, forearm, wrist and fingers. The task-oriented training will be conducted in seating position with a table in front. Each training task will be repeated for 10 repetitions per set with 1 minute of rest between sets.The progressions are repositioning from gravity eliminate to against position, improve movement quality, increasing number of sets and shortening rest period.