Real-time functional brain mapping using electrocorticography

Area of Science:

• Neuroscience
• Biomedical Engineering
• Clinical Neurology

Background:

• Electrocorticography (ECoG) is crucial for understanding brain activity.
• Identifying specific cortical areas, like the sensorimotor cortex, is vital for surgical planning and research.
• Current mapping techniques can be time-consuming and complex.

Purpose of the Study:

• To demonstrate the feasibility of real-time cortical mapping using ECoG.
• To validate a novel method for identifying functional brain regions.
• To establish a reliable clinical tool for brain mapping.

Main Methods:

• Utilized subdural electrode arrays to record ECoG signals.
• Analyzed signal power in higher spectral frequencies (76-200 Hz), termed the "chi-index".
• Performed both offline mapping with baseline/movement tasks and online mapping during a handshake task.

Main Results:

• Successfully mapped the hand area offline in eight individuals.
• Identified the hand sensorimotor cortex online in one patient during a handshake.
• Demonstrated the "chi-index" as a reliable correlate of local cortical function.

Conclusions:

• Real-time cortical mapping is feasible using high-frequency ECoG signals.
• The "chi-index" offers a generic, reliable, and clinically useful correlate of local brain activity.
• This technique has potential applications in neurosurgery and brain-computer interfaces.