Developmental profile of physiological high-frequency oscillations in the human brain

Area of Science:

• Neuroscience
• Epileptology
• Pediatric Neurology

Background:

• High-frequency oscillations (HFOs) are potential EEG biomarkers for identifying the epileptogenic zone in epilepsy surgery.
• The interpretation of physiological HFOs in healthy brain tissue is challenging, especially in pediatric populations undergoing significant EEG maturation.
• The developmental trajectory of physiological HFOs in children is not well understood.

Purpose of the Study:

• To characterize the developmental profile of physiological high-frequency oscillations (HFOs) in pediatric patients.
• To create a normative, age-dependent atlas of non-spike HFOs in the developing pediatric brain.
• To assess how HFO characteristics (rate, power, peak frequency, duration) change with age and their topological distribution.

Main Methods:

• Utilized a large multi-institutional cohort of 185 pediatric patients with intracranial EEG data.
• Developed automated HFO detectors combined with deep learning for artifact rejection and spike-HFO classification to identify physiological HFOs.
• Analyzed HFO characteristics and their distribution across three age groups (0-6, 7-12, ≥13 years), assessing correlations with age.

Main Results:

• Demonstrated significant age-related shifts in HFO distribution, with rates decreasing fronto-parieto-temporally and increasing occipitally with age.
• Observed a modest age-related increase in HFO power, particularly in older children, and longer HFO duration in younger children.
• Peak HFO frequency remained consistent across all age groups.

Conclusions:

• Established normative, age-dependent patterns for physiological HFOs in the pediatric brain.
• These findings provide a crucial reference for interpreting HFOs as spatial EEG biomarkers.
• The developmental atlas can improve the precision of epileptogenic zone delineation in pediatric epilepsy surgery.