fNIRS-BCI Neurofeedback in Stroke Rehabilitation

Utilizing a Brain-Computer Interface for Observational Imitation Training to Enhance Upper Limb Motor Recovery Post-Stroke: A Randomized Controlled Trial

Objectives: 1) To compare the effects of closed-loop brain-computer interface (BCI) driven observational imitation training versus sham BCI open-loop observational imitation training on improving upper limb motor functions in patients with stroke; 2) To investigate whether stroke patients receiving closed-loop training exhibit higher activation levels in the mirror neurons, measured by event-related desynchronization (ERD), compared to those receiving open-loop training.

Hypothesis to be tested: The closed-loop training is more effective than open-loop training in improving upper limb motor outcomes, and there is an increase in the mirror neurons activity in those receiving closed-loop training.

Design and subjects: A randomized controlled trial with 44 participants with stroke.

Study instruments: Functional near-infrared spectroscopy (fNIRS)-based BCI and electroencephalography (EEG).

Interventions: In the BCI training, participants will engage in kinesthetic motor imagery. When the M1 activation level recorded by fNIRS surpasses a predefined threshold, participants will receive visual feedback to guide them to imitate the movement. However, for participants in the sham BCI group, the visual feedback will be given will be given constantly. Both types of training consist of ten sessions.

Main outcome measures: Upper limb motor tests and the activity of mirror neurons measured by sensorimotor ERD using EEG.

Data analysis: Analysis of variance and correlation. Expected results: The closed-loop BCI-driven observational imitation training is more effective than sham BCI open-loop training on enhancing hemiplegic upper limb functions and the activation of the mirror neurons in patients after stroke.

Study Overview

• Status: Recruiting
• Conditions: Stroke
• Intervention / Treatment: Device: Brain-computer interface; Device: Sham brain-computer interface

Detailed Description

Objectives: 1) To compare the effects of closed-loop brain-computer interface (BCI) driven observational imitation training versus sham BCI open-loop observational imitation training on improving upper limb motor functions in patients with stroke; 2) To investigate whether stroke patients receiving closed-loop training exhibit higher activation levels in the mirror neurons, measured by event-related desynchronization (ERD), compared to those receiving open-loop training.

Hypothesis to be tested: The closed-loop training is more effective than open-loop training in improving upper limb motor outcomes, and there is an increase in the mirror neurons activity in those receiving closed-loop training.

Design and subjects: A randomized controlled trial with 44 participants with stroke.

Study instruments: Functional near-infrared spectroscopy (fNIRS)-based BCI and electroencephalography (EEG).

Interventions: In the BCI training, participants will engage in kinesthetic motor imagery. When the M1 activation level recorded by fNIRS surpasses a predefined threshold, participants will receive visual feedback to guide them to imitate the movement. However, for participants in the sham BCI group, the visual feedback will be given constantly. Both types of training consist of ten sessions.

Main outcome measures: Upper limb motor tests and the activity of mirror neurons measured by sensorimotor ERD using EEG.

Data analysis: Analysis of variance and correlation. Expected results: The closed-loop BCI-driven observational imitation training is more effective than sham BCI open-loop training on enhancing hemiplegic upper limb functions and the activation of the mirror neurons in patients after stroke.

• Study Type: Interventional
• Enrollment (Estimated): 44
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Jack Jiaqi Zhang, PhD; Phone Number: 6696 27666696; Email: jack-jiaqi.zhang@polyu.edu.hk

Study Locations

• Hong Kong
  • Hong Kong, Hong Kong, 000000
    • Recruiting
    • Jack Jiaqi Zhang
    • Contact: Jack Jiaqi Zhang, PhD; Phone Number: 27666696; Email: jack-jiaqi.zhang@polyu.edu.hk
    • Principal Investigator: Jack Jiaqi Zhang, PhD
    • Contact: Sofina Chan, MA; Email: sofina.chan@connect.polyu.hk

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria

1. unilateral upper extremity motor deficits caused by ischemic stroke, confirmed by medical documents such as discharge summary and/or neuroimaging examinations.
2. chronic phase of stroke, i.e., time after stroke onset more than six months.
3. aged between 18 and 75 years old.
4. with mildly-to-moderately impaired upper limb functional activity that is stratified according to the levels 3-7 in the Functional Test for the Hemiplegic Upper Extremity.
5. able to give informed written consent to participate in the study.
6. able to read and understand traditional Chinese.

Exclusion Criteria

1. previous diagnosis of any neurological disease excluding ischemic stroke.
2. presence of any sign of cognitive problems (The Montreal cognitive assessment Hong Kong version<22/30).
3. Severe spasticity measured by the Modified Ashworth Scale score>2 in the hand, wrist or elbow extensor muscle in the hemiparetic upper extremity.
4. with other notable impairments of the upper limb not caused by stroke (e.g., bone fracture in the past year, congenital deformity, or other impairments).
5. current participation in any other treatment programme or clinical study involving exercise, non-invasive brain stimulation, or BCI/neurofeedback.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: BCI neurofeedback training; Patients will perform kinesthetic motor imagery of the affected upper extremity in response to auditory cues from the BCI system. The averaged oxygenated hemoglobin (HbO) level, extracted from optimal channels identified during the localizer session, will serve as signal intensity. This intensity, quantified as percent signal change relative to baseline, will trigger neurofeedback when reaching a predefined threshold. Visual feedback, delivered via the digital mirror therapy system, will guide patients to perform observational imitation tasks using bilateral upper extremities. Each session will include 5-6 movements tailored to the patient's functional performance. After observational imitation training, patients will practice functional adaptation tasks in a virtual environment, where they apply learned movements to functional activities. Sessions will last approximately 75 minutes.	Device: Brain-computer interface; Patients will perform kinesthetic motor imagery of the affected upper extremity in response to auditory cues from the BCI system. The averaged oxygenated hemoglobin (HbO) level, extracted from optimal channels identified during the localizer session, will serve as signal intensity. This intensity, quantified as percent signal change relative to baseline, will trigger neurofeedback when reaching a predefined threshold. Visual feedback, delivered via the digital mirror therapy system, will guide patients to perform observational imitation tasks using bilateral upper extremities. Each session will include 5-6 movements tailored to the patient's functional performance. After observational imitation training, patients will practice functional adaptation tasks in a virtual environment, where they apply learned movements to functional activities. Sessions will last approximately 75 minutes.
Sham Comparator: Sham BCI neurofeedback training; In the sham group, patients will wear a similar headset equipment as those in the BCI group. However, the visual feedback provided through the digital mirror therapy system will not be based on their own brain activity. Instead, it will be derived from the brain activity of a participant in the BCI group using the simulation mode of Turbo-Satori. Patients in the sham group will receive constant visual feedback, with a fixed duration of 60 seconds for motor imagery, regardless of their actual brain signals. Like the BCI group, patients will be instructed to use kinesthetic motor imagery and imitate the movement when receiving visual feedback, and practice functional adaptation tasks after observational imitation training. The sham training will also last for around 75 minutes per session.	Device: Sham brain-computer interface; In the sham group, patients will wear a similar headset equipment as those in the BCI group. However, the visual feedback provided through the digital mirror therapy system will not be based on their own brain activity. Instead, it will be derived from the brain activity of a participant in the BCI group using the simulation mode of Turbo-Satori. Patients in the sham group will receive constant visual feedback, with a fixed duration of 60 seconds for motor imagery, regardless of their actual brain signals. Like the BCI group, patients will be instructed to use kinesthetic motor imagery and imitate the movement when receiving visual feedback, and practice functional adaptation tasks after observational imitation training. The sham training will also last for around 75 minutes per session.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
The Fugl-Meyer Assessment - Upper Extremity Scores (FMA-UE)	The Fugl-Meyer Assessment - Upper Extremity Scores (FMA-UE) evaluates upper limb motor impairment post-stroke. It assesses the movement, coordination, and reflex actions of the hemiplegic upper limb. The total scores are 66.	Baseline
The Fugl-Meyer Assessment - Upper Extremity Scores (FMA-UE)	The Fugl-Meyer Assessment - Upper Extremity Scores (FMA-UE) evaluates upper limb motor impairment post-stroke. It assesses the movement, coordination, and reflex actions of the hemiplegic upper limb. The total scores are 66.	At 2 weeks
The Fugl-Meyer Assessment - Upper Extremity Scores (FMA-UE)	The Fugl-Meyer Assessment - Upper Extremity Scores (FMA-UE) evaluates upper limb motor impairment post-stroke. It assesses the movement, coordination, and reflex actions of the hemiplegic upper limb. The total scores are 66.	At one-month

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
The Action Research Arm Test (ARAT)	The Action Research Arm Test (ARAT) is an assessment for upper limb functional activities post-stroke, with four subscales to evaluate grasp, grip, pinch, and gross movement, with total scores of 57.	Baseline
The Action Research Arm Test (ARAT)	The Action Research Arm Test (ARAT) is an assessment for upper limb functional activities post-stroke, with four subscales to evaluate grasp, grip, pinch, and gross movement, with total scores of 57.	At 2 weeks
The Action Research Arm Test (ARAT)	The Action Research Arm Test (ARAT) is an assessment for upper limb functional activities post-stroke, with four subscales to evaluate grasp, grip, pinch, and gross movement, with total scores of 57.	At one-month

Collaborators and Investigators

• Sponsor: The Hong Kong Polytechnic University
• Collaborators: Tung Wah Hospital, Queen Mary Hospital and University Hospital RWTH Aachen/RWTH Aachen University

Study record dates

Study Major Dates

• Study Start (Actual): December 12, 2024
• Primary Completion (Estimated): September 30, 2025
• Study Completion (Estimated): December 31, 2025

Study Registration Dates

• First Submitted: July 10, 2024
• First Submitted That Met QC Criteria: July 10, 2024
• First Posted (Actual): July 16, 2024

Study Record Updates

• Last Update Posted (Actual): August 22, 2025
• Last Update Submitted That Met QC Criteria: August 16, 2025
• Last Verified: December 1, 2024

More Information

Terms related to this study

• Keywords: Stroke; Brain-computer interface
• Additional Relevant MeSH Terms: Cerebrovascular Disorders; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Vascular Diseases; Cardiovascular Diseases; Stroke
• Other Study ID Numbers: HSEARS20231203001

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No