The association of magnetoencephalography high‐frequency oscillations with epilepsy types and a ripple‐based method with source‐level connectivity for mapping epilepsy sources

• Published in: CNS neuroscience & therapeutics Vol. 29; no. 5; pp. 1423 - 1433
• Main Authors: Shi, Li‐juan, Li, Can‐Cheng, Lin, Yi‐cong, Ding, Cheng‐tao, Wang, Yu‐ping, Zhang, Ji‐cong
• Format: Journal Article
• Language: English
• Published: England John Wiley & Sons, Inc 01.05.2023; John Wiley and Sons Inc
• Subjects: Accuracy; Algorithms; Biomarkers; Clinical outcomes; Convulsions & seizures; Decomposition; Drug resistance; Electroencephalography; Epilepsy; Epilepsy - surgery; Epilepsy, Temporal Lobe - surgery; Frontal lobe; functional connectivity; Humans; Inverse problems; Localization; Magnetoencephalography; MEG; Occipital lobe; Original; Oscillations; Parietal lobe; ripple; Seizures; source location; spatial complexity; Surgery; Temporal Lobe; tucker decomposition; Beijing China; China; functional connectivity; tucker decomposition; source location; ripple; spatial complexity; MEG
• ISSN: 1755-5930; 1755-5949
• DOI: 10.1111/cns.14115

Objective To explore the association between high‐frequency oscillations (HFOs) and epilepsy types and to improve the accuracy of source localization. Methods Magnetoencephalography (MEG) ripples of 63 drug‐resistant epilepsy patients were detected. Ripple rates, distribution, spatial complexity, and the clustering coefficient of ripple channels were used for the preliminary classification of lateral temporal lobe epilepsy (LTLE), mesial temporal lobe epilepsy (MTLE), and nontemporal lobe epilepsy (NTLE), mainly frontal lobe epilepsy (FLE). Furthermore, the seizure site identification was improved using the Tucker LCMV method and source‐level betweenness centrality. Results Ripple rates were significantly higher in MTLE than in LTLE and NTLE (p < 0.05). The LTLE and MTLE were mainly distributed in the temporal lobe, followed by the parietal lobe, occipital lobe, and frontal lobe, whereas MTLE ripples were mainly distributed in the frontal lobe, then parietal lobe and occipital lobe. Nevertheless, the NTLE ripples were primarily in the frontal lobe and partially in the occipital lobe (p < 0.05). Meanwhile, the spatial complexity of NTLE was significantly higher than that of LTLE and MTLE and was lowest in MTLE (p < 0.01). However, an opposite trend was observed for the standardized clustering coefficient compared with spatial complexity (p < 0.01). Finally, the tucker algorithm showed a higher percentage of ripples at the surgical site when the betweenness centrality was added (p < 0.01). Conclusion This study demonstrated that HFO rates, distribution, spatial complexity, and clustering coefficient of ripple channels varied considerably among the three epilepsy types. Additionally, tucker MEG estimation combined with ripple rates based on the source‐level functional connectivity is a promising approach for presurgical epilepsy evaluation. High‐frequency oscillations rates, distribution, spatial complexity, and clustering coefficient of ripple channel vary among lateral temporal lobe epilepsy (LTLE), mesial temporal lobe epilepsy (MTLE), and nontemporal lobe epilepsy (NTLE, mainly frontal lobe epilepsy, FLE). Additionally, tucker estimation of MEG combined with ripple based on the source‐level functional connectivity proves promising for presurgical epilepsy evaluation.