Abstract
Objective: To determine the origin and dynamic characteristics of the generalised hyper-synchronous spike and wave (SW) discharges in childhood absence epilepsy (CAE). Methods: We applied nonlinear methods, the error reduction ratio (ERR) causality test and cross-frequency analysis, with a nonlinear autoregressive exogenous (NARX) model, to electroencephalograms (EEGs) from CAE, selected with stringent electro-clinical criteria (17 cases, 42 absences). We analysed the pre-ictal and ictal strength of association between homologous and heterologous EEG derivations and estimated the direction of synchronisation and corresponding time lags. Results: A frontal/fronto-central onset of the absences is detected in 13 of the 17 cases with the highest ictal strength of association between homologous frontal followed by centro-temporal and fronto-central areas. Delays consistently in excess of 4 ms occur at the very onset between these regions, swiftly followed by the emergence of “isochronous” (0–2 ms) synchronisation but dynamic time lag changes occur during SW discharges. Conclusions: In absences an initial cortico-cortical spread leads to dynamic lag changes to include periods of isochronous interhemispheric synchronisation, which we hypothesize is mediated by the thalamus. Significance: Absences from CAE show ictal epileptic network dynamics remarkably similar to those observed in WAG/Rij rats which guided the formulation of the cortical focus theory.
| Original language | English |
|---|---|
| Pages (from-to) | 602-617 |
| Number of pages | 16 |
| Journal | Clinical Neurophysiology |
| Volume | 129 |
| Issue number | 3 |
| Early online date | 8 Jan 2018 |
| DOIs | |
| Publication status | Published - 1 Mar 2018 |
| Externally published | Yes |
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Keywords
- Absence
- Cortical focus theory
- ERR causality test
- Nonlinear
- Thalamus
- Zero-Lag
ASJC Scopus subject areas
- Sensory Systems
- Neurology
- Clinical Neurology
- Physiology (medical)
Cite this
The cortical focus in childhood absence epilepsy; evidence from nonlinear analysis of scalp EEG recordings. / Sarrigiannis, Ptolemaios G.; Zhao, Yifan; He, Fei; Billings, Stephen A.; Baster, Kathleen; Rittey, Chris; Yianni, John; Zis, Panagiotis; Wei, Hualiang; Hadjivassiliou, Marios; Grünewald, Richard.
In: Clinical Neurophysiology, Vol. 129, No. 3, 01.03.2018, p. 602-617.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - The cortical focus in childhood absence epilepsy; evidence from nonlinear analysis of scalp EEG recordings
AU - Sarrigiannis, Ptolemaios G.
AU - Zhao, Yifan
AU - He, Fei
AU - Billings, Stephen A.
AU - Baster, Kathleen
AU - Rittey, Chris
AU - Yianni, John
AU - Zis, Panagiotis
AU - Wei, Hualiang
AU - Hadjivassiliou, Marios
AU - Grünewald, Richard
PY - 2018/3/1
Y1 - 2018/3/1
N2 - Objective: To determine the origin and dynamic characteristics of the generalised hyper-synchronous spike and wave (SW) discharges in childhood absence epilepsy (CAE). Methods: We applied nonlinear methods, the error reduction ratio (ERR) causality test and cross-frequency analysis, with a nonlinear autoregressive exogenous (NARX) model, to electroencephalograms (EEGs) from CAE, selected with stringent electro-clinical criteria (17 cases, 42 absences). We analysed the pre-ictal and ictal strength of association between homologous and heterologous EEG derivations and estimated the direction of synchronisation and corresponding time lags. Results: A frontal/fronto-central onset of the absences is detected in 13 of the 17 cases with the highest ictal strength of association between homologous frontal followed by centro-temporal and fronto-central areas. Delays consistently in excess of 4 ms occur at the very onset between these regions, swiftly followed by the emergence of “isochronous” (0–2 ms) synchronisation but dynamic time lag changes occur during SW discharges. Conclusions: In absences an initial cortico-cortical spread leads to dynamic lag changes to include periods of isochronous interhemispheric synchronisation, which we hypothesize is mediated by the thalamus. Significance: Absences from CAE show ictal epileptic network dynamics remarkably similar to those observed in WAG/Rij rats which guided the formulation of the cortical focus theory.
AB - Objective: To determine the origin and dynamic characteristics of the generalised hyper-synchronous spike and wave (SW) discharges in childhood absence epilepsy (CAE). Methods: We applied nonlinear methods, the error reduction ratio (ERR) causality test and cross-frequency analysis, with a nonlinear autoregressive exogenous (NARX) model, to electroencephalograms (EEGs) from CAE, selected with stringent electro-clinical criteria (17 cases, 42 absences). We analysed the pre-ictal and ictal strength of association between homologous and heterologous EEG derivations and estimated the direction of synchronisation and corresponding time lags. Results: A frontal/fronto-central onset of the absences is detected in 13 of the 17 cases with the highest ictal strength of association between homologous frontal followed by centro-temporal and fronto-central areas. Delays consistently in excess of 4 ms occur at the very onset between these regions, swiftly followed by the emergence of “isochronous” (0–2 ms) synchronisation but dynamic time lag changes occur during SW discharges. Conclusions: In absences an initial cortico-cortical spread leads to dynamic lag changes to include periods of isochronous interhemispheric synchronisation, which we hypothesize is mediated by the thalamus. Significance: Absences from CAE show ictal epileptic network dynamics remarkably similar to those observed in WAG/Rij rats which guided the formulation of the cortical focus theory.
KW - Absence
KW - Cortical focus theory
KW - ERR causality test
KW - Nonlinear
KW - Thalamus
KW - Zero-Lag
UR - http://www.scopus.com/inward/record.url?scp=85041595105&partnerID=8YFLogxK
U2 - 10.1016/j.clinph.2017.11.029
DO - 10.1016/j.clinph.2017.11.029
M3 - Article
VL - 129
SP - 602
EP - 617
JO - Clinical Neurophysiology
JF - Clinical Neurophysiology
SN - 1388-2457
IS - 3
ER -