Temporal-spatial characteristics of phase-amplitude coupling in electrocorticogram for human temporal lobe epilepsy

• Published in: Clinical neurophysiology 2017-09, Vol.128 (9), p.1707-1718
• Main Authors: Zhang, Ruihua, Ren, Ye, Liu, Chunyan, Xu, Na, Li, Xiaoli, Cong, Fengyu, Ristaniemi, Tapani, Wang, YuPing
• Format: Article
• Language: English
• Subjects: Adult; Brain Waves - physiology; Cross-frequency coupling; ECoG; Electrocorticography - methods; Electrodes, Implanted; Epilepsy, Temporal Lobe - diagnosis; Epilepsy, Temporal Lobe - physiopathology; Fall-max pattern; Female; Hippocampus - physiopathology; Humans; Male; Middle Aged; Modulation index; Temporal Lobe - physiopathology; Temporal lobe epilepsy; Time Factors; Young Adult
• ISSN: 1388-2457; 1872-8952
• DOI: 10.1016/j.clinph.2017.05.020

•Phase-amplitude coupling (PAC) can provide relevant information for the lateralization and localization of epileptic foci.•The “fall-max” pattern was found to be a reliable biomarker in the mid-seizure period.•Strong PAC appeared mainly between δ, θ, and α oscillations and γ and ripple oscillations. Neural activity of the epileptic human brain contains low- and high-frequency oscillations in different frequency bands, some of which have been used as reliable biomarkers of the epileptogenic brain areas. However, the relationship between the low- and high-frequency oscillations in different cortical areas during the period from pre-seizure to post-seizure has not been completely clarified. We recorded electrocorticogram data from the temporal lobe and hippocampus of seven patients with temporal lobe epilepsy. The modulation index based on the Kullback-Leibler distance and the phase-amplitude coupling co-modulogram were adopted to quantify the coupling strength between the phase of low-frequency oscillations (0.2–10Hz) and the amplitude of high-frequency oscillations (11–400Hz) in different seizure epochs. The time-varying phase-amplitude modulogram was used to analyze the phase-amplitude coupling pattern during the entire period from pre-seizure to post-seizure in both the left and right temporal lobe and hippocampus. Channels with strong modulation index were compared with the seizure onset channels identified by the neurosurgeons and the resection channels in the clinical surgery. The phase-amplitude coupling strength (modulation index) increased significantly in the mid-seizure epoch and decrease significantly in seizure termination and post-seizure epochs (p