Clinical Impact and Implication of Real-Time Oscillation Analysis for Language Mapping

Area of Science:

• Neurosurgery
• Neurophysiology
• Brain Mapping

Background:

• Developed a functional brain analysis system for real-time task-related electrocorticography (ECoG).
• Hypothesized high gamma activity (HGA) mapping offers superior spatial/temporal resolution and signal-to-noise ratios.
• Evaluated the system's clinical practice potential.

Purpose of the Study:

• To assess the clinical feasibility and accuracy of real-time HGA mapping.
• To compare HGA mapping with electrocortical stimulation (ECS) for identifying functional brain areas.
• To evaluate the sensitivity and specificity of HGA mapping for language areas.

Main Methods:

• Recorded ECoG during language tasks in seven awake craniotomy patients using subdural grids.
• Obtained real-time HGA (60-170 Hz) maps.
• Validated HGA mapping results with ECS mapping and compared sensitivity/specificity.
• Performed bedside HGA-ECS mapping in five epilepsy patients for reference.

Main Results:

• Real-time HGA mapping successfully identified functional brain areas, comparable to ECS mapping.
• Achieved high sensitivity (90.1% ± 11.2%) and specificity (90.0% ± 4.2%) for language areas.
• Demonstrated consistency between HGA-positive and ECS-positive regions across patient groups without significant differences.

Conclusions:

• Real-time HGA mapping is clinically feasible for awake craniotomy, enabling simple and rapid detection of language areas.
• The mapping results were highly accurate despite a noisy environment.
• Further research into HGA mapping could elucidate complex brain functions and networks.