Effects of Transcutaneous Electrical Nerve Stimulation on Cognitive Function and Upper Limb Motor Function in People With Chronic Stroke

A Randomized Controlled Clinical Trial of Transcutaneous Electrical Nerve Stimulation on Cognitive Function and Upper Limb Motor Function in People With Chronic Stroke

Upper limb impairment is present in more than 85% of people with stroke, which greatly affect the quality of life, social participation, and performance of daily activities of people with stroke. Previous study also revealed that 53.4% of people after stroke experienced cognitive impairment. Different cognitive domains might be affected following stroke, such as attention, memory, language, and orientation, and the problems with memory are often prominent. Yet, there is no effective treatment for the post-stroke cognitive impairment.

Transcutaneous spinal cord stimulation (tSCS) and transcutaneous vagus nerve stimulation (tVNS) are simple and non-invasive treatment to improve upper limb motor function and cognitive function. However, no existing studies have explored on the effects of tSCS and tVNS on cognitive function in people with stroke. Therefore, the purpose of this study is to evaluate the effectiveness of transcutaneous electrical nerve stimulation (TENS) on improving upper limb function and cognitive function in people with chronic stroke.

This study aims to investigate the effects of three intervention protocols in people with stroke. The participants in Group A will receive tSCS on C6 and T5 level of the spine with upper limb exercises. The participants in Group B will receive tVNS on the cymba conchae of left outer ear with upper limb exercises. The participants in Group C will receive placebo stimulation with upper limb exercises.

Inclusion Criteria:

1. aged between 50 and 80;
2. have suffered from a single stroke at least 6 months;
3. had volitional control of the non-paretic arm and at least minimal antigravity movement in the paretic shoulder;

Exclusion Criteria:

1. have cardiac pacemaker or cochlear implant;
2. have other neurological diseases;
3. are taking medication that may affect measured outcomes;
4. have skin lesions, infection, or inflammation near selected position;
5. are participating in other drug/treatment programs.