Cortical Activation Response during Acupuncture Intervention for Hemiplegia Limbs in Stroke Patients: A Preliminary fNIRS Study

Observation of the cortical response to specific therapy in real-time would provide valuable evidence for the neural mechanisms underlying stroke rehabilitation. This study aimed to explore the cortical response during acupuncture in hemiplegic limb acupoints for stroke patients. Nineteen stroke patients were recruited for the measurement of cerebral hemodynamics during resting state and acupuncture state based on functional near-infrared spectroscopy (fNIRS). Wavelet amplitude (WA) was used to describe the cortical activation based on the time-frequency analysis of fNIRS signals. Results showed significantly higher WA of bilateral prefrontal and motor cortex during acupuncture state than the resting state. Additionally, significantly negative correlation was observed between the motor score and increased WA in the contralesional hemisphere. These findings suggest that there were increased cortical activation of bilateral hemispheres and patients with severe motor dysfunctions had more activation of contralesional hemisphere in response to the acupuncture intervention. This study provides preliminary evidence about the neural mechanism underlying acupuncture for motor impairment and suggests the role of fNIRS in stroke rehabilitation assessment.