A Neurofeedback Interface in Poststroke Neuromodulation Using TMS-fNIRS

Stroke is a type of cerebrovascular disease, and the primary characteristic of post-stroke brains is pathological changes in cerebral hemodynamics. Therefore, hemodynamic signals may provide straightforward information for guiding post-stroke neuromodulation therapy. Transcranial magnetic stimulation (TMS), a non-invasive neurostimulation modality, has been extensively used in post-stroke rehabilitation. However, current TMS-based neuromodulation therapy demonstrates a large treatment response variability due to its open-loop nature. To address this challenge, the research team will develop a novel form of closed-loop neurofeedback interfaces which controls the timing of TMS pulses precisely based on neural biomarkers from functional near-infrared spectroscopy (fNIRS) and test the accuracy of the adaptive neurofeedback system in healthy adults. After establishing the TMS-based neurofeedback interface, a proof-of-concept study enrolling postacute stroke patients will be performed to evaluate the efficacy of the TMS neurofeedback interface in enhancing motor control of the hemiplegic upper extremity and cortical excitability of the ipsilesional motor cortex. These findings will verify whether the proposed fNIRS-controlled TMS neurofeedback interface can be clinically feasible as a form of post-stroke neuromodulation therapy. Additionally, the results will significantly contribute to the scientific understanding of how neuromodulation improves hemodynamic signals in a closed-loop manner, thereby enhancing functional recovery in poststroke survivors.

Inclusion criteria

Participants who meet the following criteria will be included:

• Diagnosed with ischemic subcortical stroke, with stroke onset≥6 months.
• Age between 18 and 80 years.
• Residual upper limb functions between levels 2-7 in the FTHUE.
• Capable of providing informed written consent.
• Capable of reading and communicating with Chinese.

Exclusion criteria

Patients who meet any of the following criteria will be excluded:

• any contraindications to TMS (screened by the safety checklist by Rossi).
• signs of cognitive impairment, with a Montreal cognitive assessment score<21/22 out of 30.
• any moderate-to-severe chronic illness, such as uncontrolled hypertension, heart disease or renal failure.

Healthy participants should be aged between 18 and 80, with no known history of neurological diseases. They should not have any moderate-to-severe chronic illness, such as uncontrolled hypertension, heart disease or renal failure.