Changes in aperiodic EEG activity following acupuncture stimulation in stroke

Area of Science:

• Neuroscience
• Biomedical Engineering
• Clinical Neurology

Background:

• Electroencephalography (EEG) measures brain activity, vital for assessing stroke therapies.
• EEG spectra contain both periodic oscillations and aperiodic background activity.
• The role of aperiodic activity in response to external stimulation is not well understood.

Purpose of the Study:

• To investigate how acupuncture stimulation affects both oscillatory and aperiodic brain activity in stroke patients.
• To identify potential EEG biomarkers for acupuncture's therapeutic effects in stroke.

Main Methods:

• Parameterized EEG power spectra from 30 stroke subjects undergoing acupuncture.
• Analyzed changes in oscillatory components (power, center frequency).
• Investigated alterations in aperiodic brain activity (exponent, offset).

Main Results:

• Acupuncture increased alpha oscillation power and center frequency in the left fronto-parietal cortex.
• Decreased aperiodic exponent and offset were observed, particularly in the ipsilesional hemisphere.
• Acupuncture enhanced interhemispheric symmetry, notably in alpha power, alpha frequency, and aperiodic exponent.

Conclusions:

• Acupuncture modulates both periodic and aperiodic EEG dynamics in stroke patients.
• Alpha oscillation characteristics and the aperiodic exponent show promise as biomarkers for acupuncture effects.
• Peripheral acupuncture stimulation demonstrably influences central brain activity in stroke recovery.