fNIRS-BCI Neurofeedback in Stroke Rehabilitation

Summary

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.

Conditions

• Stroke

Interventions

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.

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.

Sponsors & Collaborators

• Tung Wah Hospital, Queen Mary Hospital and University Hospital RWTH Aachen/RWTH Aachen University

  collaborator UNKNOWN

• The Hong Kong Polytechnic University

  lead OTHER

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

DOUBLE

Model

PARALLEL

Eligibility

Min Age

18 Years

Max Age

75 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2024-12-12

Primary Completion

2025-09-30

Completion

2025-12-31

Countries

• Hong Kong

Study Locations