fNIRS-BCI Neurofeedback in Stroke Rehabilitation

Official title

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

Overview

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.

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.

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 p
• 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 bra

Primary outcome measures

• The Fugl-Meyer Assessment - Upper Extremity Scores (FMA-UE) [Time frame: Baseline]
• The Fugl-Meyer Assessment - Upper Extremity Scores (FMA-UE) [Time frame: At 2 weeks]
• The Fugl-Meyer Assessment - Upper Extremity Scores (FMA-UE) [Time frame: At one-month]

Secondary outcome measures (3)

• The Action Research Arm Test (ARAT) [Time frame: Baseline]
• The Action Research Arm Test (ARAT) [Time frame: At 2 weeks]
• The Action Research Arm Test (ARAT) [Time frame: At one-month]

Eligibility criteria

Inclusion criteria

• unilateral upper extremity motor deficits caused by ischemic stroke, confirmed by medical documents such as discharge summary and/or neuroimaging examinations.
• chronic phase of stroke, i.e., time after stroke onset more than six months.
• aged between 18 and 75 years old.
• 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.
• able to give informed written consent to participate in the study.
• able to read and understand traditional Chinese.

Exclusion criteria

• previous diagnosis of any neurological disease excluding ischemic stroke.
• presence of any sign of cognitive problems (The Montreal cognitive assessment Hong Kong version<22/30).
• Severe spasticity measured by the Modified Ashworth Scale score>2 in the hand, wrist or elbow extensor muscle in the hemiparetic upper extremity.
• 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).
• current participation in any other treatment programme or clinical study involving exercise, non-invasive brain stimulation, or BCI/neurofeedback.

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation

Randomized

Model

Parallel assignment

Masking

Double blind

Primary purpose

Treatment

Study locations

Hong Kong · 1 center

• Jack Jiaqi Zhang — Hong Kong

Publications

• Zhang JJ, Lin R, Zeng RR, Tang M, Chan SSY, Zhang BB, Sun R, Kranz GS, Lau SCL, Luhrs M, Fong KNK, Mathiak K, Mehler DMA, Lau GKK. Using a functional near-infrared spectroscopy-guided brain-computer interface to facilitate observational imitation after stroke. Ann Phys Rehabil Med. 2026 Jun 25;69(6):102149. doi: 10.1016/j.rehab.2026.102149. Online ahead of print. PMID 42349111

Identifiers

NCT: NCT06503484 · HSEARS20231203001

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗