Abstract
High-frequency oscillations (HFOs), including ripples (Rs) and fast ripples (FRs), are promising biomarkers of epileptogenesis, but their clinical utility is limited by the lack of a standardized approach to identification. We set out to determine whether electroencephalographers experienced in HFO analysis can reliably identify and quantify interictal HFOs. Two blinded raters independently reviewed 10 intraoperative electrocorticography (ECoG) samples from epilepsy surgery cases, and 10 scalp EEG samples from epilepsy monitoring unit evaluations. HFOs were visually marked using bandpass filters (R, 80–250 Hz; FR, 250–500 Hz) with a sampling frequency of 2,000 Hz. There was agreement as to the presence or absence of epileptiform discharges (EDs), Rs, and FRs, in 17, 18, and 18 cases, respectively. Interrater reliability (IRR) was favorable with κ = 0.70, 0.80, and 0.80, respectively, and similar for ECoG and scalp electroencephalography (EEG). Furthermore, interclass correlation for rates of Rs (0.99, 95% confidence interval [CI] 0.96–0.99) and FRs (0.77, 95% CI 0.41–0.91) were superior in comparison to EDs (0.37, 95% CI −0.60 to 0.75). Our data suggest that HFO identification and quantification are reliable among experienced electroencephalographers. Our findings support the reliability of utilizing HFO data in both research and clinical arenas.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 127-132 |
| Number of pages | 6 |
| Journal | Epilepsia Open |
| Volume | 3 |
| Issue number | S2 |
| DOIs | |
| State | Published - Dec 2018 |
Funding
This study was accomplished with support from the Elsie and Isaac Fogelman Endowment, the Hughes Family Foundation, and the UCLA Children’s Discovery and Innovation Institute. HN is supported by Susan Spencer Clinical Research Training Fellowship in Epilepsy from the American Academy of Neurology, with funding from the American Epilepsy Society, the American Brain Foundation, and the Epilepsy Foundation. JYW has received research funding from Novartis, GW Pharmaceuticals, the National Institute of Neurological Disorders and Stroke/National Institutes of Health (NINDS/NIH; R01 NS082649, U01 NS082320, U54 NS092090, U01 NS092595), and the Today’s and Tomorrow’s Children Fund from UCLA Mattel Children’s Hospital at the University of California Los Angeles. RS serves on scientific advisory boards for and has received honoraria and funding for travel from Eisai, UCB Pharma, Sunovion, Supernus, Upsher-Smith, Acorda, and Lundbeck Pharma; receives royalties from the publication of “Pediatric Neurology,” 3rd ed. (Demos Publishing, 2008) and “Epilepsy: Mechanisms, Models, and Translational Perspectives” (CRC Press, 2011); serves on speakers’ bureaus for and has received speaker honoraria from Eisai, UCB, GlaxoSmithKline, Cyberonics, Supernus, and Lundbeck. SAH has received research support from the Epilepsy Therapy Project, the Milken Family Foundation, the Hughes Family Foundation, the Elsie and Isaac Fogelman Endowment, Eisai, Lund-beck, Insys, GW Pharmaceuticals, UCB, and the NIH (R34MH089299), and has received honoraria for service on the scientific advisory boards of Questcor, Mallinckrodt, Insys, UCB, and Upsher-Smith Labs, for service as a consultant to Eisai, UCB, and Mallinckrodt, and for service on the speakers’ bureau of Mallinckrodt. We are indebted to Andrea Duran, Chris Gruden, Miriam Kay, Jimmy C. Nguyen, Conrad Szeliga, Maria Garcia Roca, Richard Le, Patrick Wilson, Kristina Murata, Natalie Ziegler, Divya Nadkarni, Rajsekar Rajaraman, Lekha M. Rao, Joyce Matsumoto, and Jason T. Lerner for their assistance in sample acquisition. This study was accomplished with support from the Elsie and Isaac Fogelman Endowment, the Hughes Family Foundation, and the UCLA Children's Discovery and Innovation Institute. HN is supported by Susan Spencer Clinical Research Training Fellowship in Epilepsy from the American Academy of Neurology, with funding from the American Epilepsy Society, the American Brain Foundation, and the Epilepsy Foundation. JYW has received research funding from Novartis, GW Pharmaceuticals, the National Institute of Neurological Disorders and Stroke/National Institutes of Health (NINDS/NIH; R01 NS082649, U01 NS082320, U54 NS092090, U01 NS092595), and the Today's and Tomorrow's Children Fund from UCLA Mattel Children's Hospital at the University of California Los Angeles. RS serves on scientific advisory boards for and has received honoraria and funding for travel from Eisai, UCB Pharma, Sunovion, Supernus, Upsher-Smith, Acorda, and Lundbeck Pharma; receives royalties from the publication of “Pediatric Neurology,” 3rd ed. (Demos Publishing, 2008) and “Epilepsy: Mechanisms, Models, and Translational Perspectives” (CRC Press, 2011); serves on speakers’ bureaus for and has received speaker honoraria from Eisai, UCB, GlaxoSmithKline, Cyberonics, Supernus, and Lundbeck. SAH has received research support from the Epilepsy Therapy Project, the Milken Family Foundation, the Hughes Family Foundation, the Elsie and Isaac Fogelman Endowment, Eisai, Lundbeck, Insys, GW Pharmaceuticals, UCB, and the NIH (R34MH089299), and has received honoraria for service on the scientific advisory boards of Questcor, Mallinckrodt, Insys, UCB, and Upsher-Smith Labs, for service as a consultant to Eisai, UCB, and Mallinckrodt, and for service on the speakers’ bureau of Mallinckrodt. We are indebted to Andrea Duran, Chris Gruden, Miriam Kay, Jimmy C. Nguyen, Conrad Szeliga, Maria Garcia Roca, Richard Le, Patrick Wilson, Kristina Murata, Natalie Ziegler, Divya Nadkarni, Rajsekar Rajaraman, Lekha M. Rao, Joyce Matsumoto, and Jason T. Lerner for their assistance in sample acquisition.
Keywords
- Fast ripple
- High-frequency oscillation
- Interrater reliability
- Ripple
ASJC Scopus subject areas
- Clinical Neurology
- Neurology