Effects of Transcutaneous Electrical Nerve Stimulation (TENS) to Improve the Cognitive Functions in Older Adults

Not Applicable

Completed

• Conditions: Mild Cognitive Impairment
• Interventions: Device: Concha TENS; Device: Control; Device: T1 TENS

• Registration Number: NCT05408689
• Lead Sponsor: The Hong Kong Polytechnic University

Brief Summary

Recent evidence has shown that transcutaneous electrical nerve stimulation (TENS) was effective in improving the cognitive function in healthy adult and people with dementia. However, lacking of evidence investigated the effect of TENS in improving the cognitive function and reversing the occurrence of dementia during the period of mild cognitive impairment (MCI), which is the crucial period to prevent the significant loss of cognition function. Therefore, the main objective of this study is to investigate the optimal TENS treatment protocol in improving the cognitive function in older adults with MCI.

Detailed Description

This study aims to investigate the effectiveness of 3 intervention protocols (1) In the T1 TENS group, the subject will receive TENS on T1 spine. (2) In the vagus nerve TENS group, the subject will receive TENS on the concha of left outer ear. (3) In the sham stimulation group, the subject will receive sham stimulation on the T1 spine, in improving the cognitive function in older adults with MCI.

Study Timeline

• Study Start: 2022-05-23
• Study First Submitted: 2022-05-29
• Study First Submitted QC: 2022-06-03
• Study First Posted: 2022-06-07
• Primary Completion: 2023-03-23
• Study Completion: 2023-03-23
• Status Verified: 2023-09
• Last Update Submitted: 2023-09-20
• Last Update Posted: 2023-09-22

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 90

Inclusion Criteria

Should fulfil the diagnosis criteria of MCI (Albert et al., 2011):

1. Concern regarding a change in cognition
2. Impairment in one or more cognitive domains
3. Preservation of independence in functional abilities
4. no signs of dementia were to be present and confirmed by the medical staff and medical records.

Exclusion Criteria

1. If their medical records reported a history of either psychiatric disorder, alcoholism, cerebral trauma, cerebrovascular disease, hydrocephalus, neoplasm, epilepsy, disturbances of consciousness, insulin-dependent diabetes mellitus or focal brain disorders;
2. Having active implants, such as cochlear implants, pacemaker;
3. Having wounds and diseased skin on the electrode position.

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Concha TENS	Concha TENS	In this study, participants will be treated 30 min per day, 3 days per week, for 10 consecutive weeks
Control	Control	In this study, participants will be treated 30 min per day, 3 days per week, for 10 consecutive weeks
T1 TENS	T1 TENS	In this study, participants will be treated 30 min per day, 3 days per week, for 10 consecutive weeks

Primary Outcome Measures

Name	Time	Method
Visual Memory Span Test	1 month follow-up (14 week)	The visual memory is measured by the visual memory span test. The subject was required to observe a given order to tap a number of block as shown by the examiners and then repeat them in forward and backward order. The difficulty will be increased when the number of blocks in a sequence increased. The more correct trials performed indicated better visual memory.
Face Recognition Test	1 month follow-up (14 week)	The visual, nonverbal long-term memory is measured by the face recognition test from the Rivermead Behavioral Memory Test (RMBT). Fifteen faces are shown successively to the subject. After an occupied interval of 5 minutes, the subjects are required to select the original 15 faces from a set of 30. The recognition score is the number of correct answers minus the number of incorrect answers. The recognition score is ranged from -15 to 15. A higher score indicated a better visual, nonverbal long term memory.
Montreal cognitive assessment (MoCA)	1 month follow-up (14 week)	The overall cognitive function is measured by the Cantonese version of MoCA. The MoCA is a widely used 10-minute cognitive screening test for detection of MCI. The MoCA test includes 8 parts with a maximum score of 30. A higher score indicated a better cognitive function. The Cantonese version of MoCA has shown good to excellent inter-rater (ICC=0.987, p\<0.001) reliability in Chinese older adults.
10 Meter Walking Test (10MWT)	1 month follow-up (14 week)	The walking speed over a short distance is measured by the 10MWT. The subject will be asked to walk 10 meter in a normal comfortable speed and maximum speed condition, respectively. The completion time will be records by stopwatch. Each condition will be repeated for 2 times. The completion time will be averaged. The shorter the completion time, the better performance is. 10MWT has shown excellent test-retest reliability (ICC=0.98) in assessing healthy older adults.
Limit of Stability (LOS)-Maximum Excursion	1 month follow-up (14 week)	The LOS is measured by the balance plate system (Bertec, Columbus, OH). During the limits of stability task, subjects were instructed to shift their weight by moving their pelvis and torso without flexing their hips or knees, keeping their heels in contact with the force plates and their arms/hands at their sides. The subjects will be instructed to shifted his or her center of mass to forward (0°), right-forward (45°), right (90°), right-backward (135°), backward (180°), left backward (225°), left (270°) and left-forward (315°), based on a visual projection of the center of mass in the current and target locations. The duration of each weight shifting trial was 10 seconds. Maximum excursion (ME) is used to assess the maximum amount the patient leaned during the trial. The ME (%) in the 8 direction will be measured. The smaller ME indicated poorer balance performance.
Digit Span Test	1 month follow-up (14 week)	The verbal short-term memory and working memory is measured by the digit span test . The subject was required to listen to a series of random numbers carefully and then repeated them in forward (forward digit span test) and backward (backward digit span test) order. Continue in the same manner by increasing the series of numbers. The difficulty will be increased when the number in a sequence increased. The forward digit span task requires verbal working memory and attention, while the backwards digit span task additionally tests cognitive control and executive function.The more correct trials performed indicated better short-term memory and work memory.
Stroop Color and Word Test	1 month follow-up (14 week)	The ability to inhibit cognitive interference is measured by the Stroop Color and Word Test. The Stroop Test consists of 3 subtasks. The first subtask shows color dots (green, blue, yellow, red) in random order. The second subtask shows the words (green, blue, red, yellow) in random order. The third task showed color words (green, blue, red, yellow) printed in a different ink color (i.e., the word blue printed in yellow ink). Participants are required to name the color of the ink as quickly as possible within 45 s in each task. The completion time and number of error is recorded in each task. The interference ratio of will be calculated as the completion time of the third task/the completion time of the first task. A higher interference score indicated poorer interference control.
Picture Recognition Test	1 month follow-up (14 week)	The visual, verbal long-term memory is measured by the picture recognition test from the RBMT. Line drawings of 15 common objects are presented one at a time. After an occupied interval of 5 minutes, the subjects are asked to select the original 15 pictures from a set of 30. The recognition score is calculated in the same way as in the Face Recognition test. The recognition score is ranged from -15 to 15. A higher score indicated a better visual, verbal long term memory.
Berg Balance Scale (BBS)	1 month follow-up (14 week)	The functional balance ability is measured by BBS. The BBS is an ordinal scale with 14 items, each item ranged from 0-4 with a total score ranged from 0-56. The higher score indicates a better balance function. Previous study has shown that BBS has good to excellent test-retest reliability (ICC=0.77-0.886) in older adults.
Limit of Stability (LOS)-Reaction Time	1 month follow-up (14 week)	The LOS is measured by the balance plate system (Bertec, Columbus, OH). During the limits of stability task, subjects were instructed to shift their weight by moving their pelvis and torso without flexing their hips or knees, keeping their heels in contact with the force plates and their arms/hands at their sides. The subjects will be instructed to shifted his or her center of mass to forward (0°), right-forward (45°), right (90°), right-backward (135°), backward (180°), left backward (225°), left (270°) and left-forward (315°), based on a visual projection of the center of mass in the current and target locations. The duration of each weight shifting trial was 10 seconds. Reaction time (RT) is used to assess the time participants take to give a movement response after cues are provided. The RT (second) in the 8 direction will be measured. The longer RT indicated poorer balance performance.
Limit of Stability (LOS)-Movement Velocity	1 month follow-up (14 week)	The LOS is measured by the balance plate system (Bertec, Columbus, OH). During the limits of stability task, subjects were instructed to shift their weight by moving their pelvis and torso without flexing their hips or knees, keeping their heels in contact with the force plates and their arms/hands at their sides. The subjects will be instructed to shifted his or her center of mass to forward (0°), right-forward (45°), right (90°), right-backward (135°), backward (180°), left backward (225°), left (270°) and left-forward (315°), based on a visual projection of the center of mass in the current and target locations. The duration of each weight shifting trial was 10 seconds. Movement velocity (MV) is used to assess the average center of gravity (COG) displacement speed. The MV (degree/second) in the 8 direction will be measured. The smaller MV indicated poorer balance performance.
6 Minutes Walking Test (6MWT)	1 month follow-up (14 week)	The aerobic capacity and walking endurance is measured by the 6MWT. The participants will be asked to walk as far as possible for 6 minutes in the 20 meters' corridor. The walking distance in 6 minutes will be records. The longer distance the subject walk, the better endurance is. The 6MWT has shown excellent test-retest reliability (ICC=0.95) in assessing healthy older adults.
Time Up and Go Test (TUG)	1 month follow-up (14 week)	The functional ability is measured by TUG. The subject will be asked to stand up from the chair, walk 3 meters, turn 180°, go back to the chair and then sit down. The completion time will be recorded. The subjects need to repeat the test for 2 times. The completion time of the 2 trials will be averaged.
Limit of Stability (LOS)-Directional Control	1 month follow-up (14 week)	The LOS is measured by the balance plate system (Bertec, Columbus, OH). During the limits of stability task, subjects were instructed to shift their weight by moving their pelvis and torso without flexing their hips or knees, keeping their heels in contact with the force plates and their arms/hands at their sides. The subjects will be instructed to shifted his or her center of mass to forward (0°), right-forward (45°), right (90°), right-backward (135°), backward (180°), left backward (225°), left (270°) and left-forward (315°), based on a visual projection of the center of mass in the current and target locations. The duration of each weight shifting trial was 10 seconds. Directional control (DC) is used to assess how much of the patient's movement was in the target direction. The DC (%) in the 8 direction will be measured. The smaller DC indicated poorer balance performance.
Community Integration Measure	1 month follow-up (14 week)	The level of community integration is assessed by Chinese version of Community Integration Measure (CIM). It is a self-report questionnaire that is easily administrated to assess the community integration level. The instrument consists of 10 items, each rated from 1 to 5, giving a total score ranging from 10 to 50. A higher score indicates greater community integration. Liu et al. reports that the Chinese version of the CIM showed good test-retest reliability (ICC=0.84) in people with stroke. A pilot study with 123 people with chronic stroke conducted as part of this research showed that CIM scores were significantly correlated with peak wrist flexion torque (r=0.203, p\<0.05), WMFT scores (r=0.194, p\<0.05) and Barthel Index scores (r=0.194, p\<0.05).
Limit of Stability (LOS)-Endpoint Excursion	1 month follow-up (14 week)	The LOS is measured by the balance plate system (Bertec, Columbus, OH). During the limits of stability task, subjects were instructed to shift their weight by moving their pelvis and torso without flexing their hips or knees, keeping their heels in contact with the force plates and their arms/hands at their sides. The subjects will be instructed to shifted his or her center of mass to forward (0°), right-forward (45°), right (90°), right-backward (135°), backward (180°), left backward (225°), left (270°) and left-forward (315°), based on a visual projection of the center of mass in the current and target locations. The duration of each weight shifting trial was 10 seconds. Endpoint excursion (EE) is used to assess how far the patient leans towards the target on his or her first attempt. The EE (%) in the 8 direction will be measured. The smaller EE indicated poorer balance performance.

Trial Locations

Locations (1)

The Hong Kong Polytechnic University; 🇭🇰 Hong Kong, Hong Kong