Table 5.

Summary of clinical studies on post-stroke patients using tVNS.

Study	No.	Targeted lesion	Study design	Intervention	Frequency	Intensity	Schedule	Follow-up	Outcome
Capone et al, 2017 [91]	14 (7)	Chronic ischemic or hemorrhagic stroke	RCT	tVNS combined with robots vs sham tVNS with robots	20 Hz	Above the detection threshold and below the pain threshold	60 min for 10 d	N/A	FMA positive
Redgrave et al, 2018 [92]	13	More than 3 months postischemic stroke with residual upper limb dysfunction	CT	tVNS with concurrent upper limb repetitive task practice	25 Hz	Maximum tolerated intensity	>300 repetitions, 3 times a week for 6 weeks	N/A	FMA-UL positive
Baig et al, 2019 [93]	12	Ischemic stroke more than 3 months prior and moderate-severe upper limb weakness	CT	functional arm movement with taVNS	25 Hz	Maximally tolerated by the participant	300 repetitions for 6 weeks	N/A	FMA-UL for proprioception and light touch sensation positiive
Wu et al, 2020 [94]	21 (10)	Subacute Ischemic Stroke	RCT	taVNS vs sham	20 Hz	Individually selected by the patients according to tolerance	30 min for 15 consecutive days	4 weeks and 12 weeks	FMA-UL, WMFT, FIM, and Brunnstrom scores positive
Chang et al, 2021 [95]	36	Chronic, moderate-severe upper limb hemiparesis	CT	Shoulder/elbow robotic therapy aired with active taVNS or sham taVNS	30 Hz	Below the patient’s reported pain threshold, with amplitudes ranging from 0.1 to 5.0 mA	1 h, 3×/week for 3 weeks	3 mo	FMA-UL, MRC, Wolf FAS, MTS positive
Li et al, 2022 [96]	60	Acute ischemic or hemorrhagic stroke	RCT	taVNS vs sham	20 Hz	According to the tolerance of each patient, and the average current intensity was 1.71±0.5 mA	20 min for 20 d	1 year	WMFT, FMA, HANDS, SIS positive

FMA-UL – Fugl-Meyer Assessment-Upper Limb; WMFT – Wolf motor function test; FIM – Functional Independence Measurement; MRC – Medical Research Council Motor Power Scale; Wolf FAS – Wolf Functional Ability Scale; MTS – Modified Tardieu Scale; HANDS – Hospital Anxiety and Depression Scale; SIS – the Stroke Impact Scale.