TY - GEN
T1 - Strength and topography of synchronization of EEG dynamics during sleep in patientswith epilepsy
AU - Krishnan, Balu
AU - Nair, Gatha
AU - Faith, Aaron
AU - Roth, Austin
AU - Kondylis, Efstathios
AU - Williams, Korwyn
AU - Tapsell, Lisa
AU - Sirven, Joseph
AU - Iasemidis, Leonidas
PY - 2011
Y1 - 2011
N2 - The occurrence of epileptic seizures and interictal epileptiform discharges (e.g., spikes, sharp waves) are common during sleep. In this study, we investigated the changes in brain dynamics during sleep and wakefulness states in two patients with focal epilepsy. The electroencephalographic (EEG) activity was recorded from scalp electrodes continuously over several days. Three different measures of dynamics were employed: The measures of Energy (E), maximumShort-TermLyapunov exponents (STLmax) and maximum Phase (φmax). on the basis of these measures we then estimated the degree of entrainment (synchronization) of dynamics between brain sites. There is a significant (p<0.001) increase in dynamical entrainment during sleep compared to wakefulness, which is indicative of a higher level of synchronization during sleep versus awake. The nonlinear dynamical measure of STLmax is more sensitive in capturing this entrainment than the classical energy or phase measures. The topography of the observed dynamical entrainment, indicates that the spatial extent of the dynamical entrainment between different brain sites during sleep is larger compared to wakefulness. These spatiotemporal findings provide new insights into brain dynamics and the topography of their synchronization during sleep, and may lead to a better understanding of seizure onset and treatments.
AB - The occurrence of epileptic seizures and interictal epileptiform discharges (e.g., spikes, sharp waves) are common during sleep. In this study, we investigated the changes in brain dynamics during sleep and wakefulness states in two patients with focal epilepsy. The electroencephalographic (EEG) activity was recorded from scalp electrodes continuously over several days. Three different measures of dynamics were employed: The measures of Energy (E), maximumShort-TermLyapunov exponents (STLmax) and maximum Phase (φmax). on the basis of these measures we then estimated the degree of entrainment (synchronization) of dynamics between brain sites. There is a significant (p<0.001) increase in dynamical entrainment during sleep compared to wakefulness, which is indicative of a higher level of synchronization during sleep versus awake. The nonlinear dynamical measure of STLmax is more sensitive in capturing this entrainment than the classical energy or phase measures. The topography of the observed dynamical entrainment, indicates that the spatial extent of the dynamical entrainment between different brain sites during sleep is larger compared to wakefulness. These spatiotemporal findings provide new insights into brain dynamics and the topography of their synchronization during sleep, and may lead to a better understanding of seizure onset and treatments.
KW - Electroencephalography
KW - Epilepsy
KW - Signal processing
KW - Sleep
KW - Spatio-temporal brain dynamics
KW - Synchronization
UR - http://www.scopus.com/inward/record.url?scp=80052182221&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=80052182221&partnerID=8YFLogxK
U2 - 10.2316/P.2011.737-046
DO - 10.2316/P.2011.737-046
M3 - Conference contribution
AN - SCOPUS:80052182221
SN - 9780889868700
T3 - Proceedings of the IASTED International Symposia on Imaging and Signal Processing in Healthcare and Technology, ISPHT 2011
SP - 83
EP - 89
BT - Proceedings of the IASTED International Symposia on Imaging and Signal Processing in Healthcare and Technology, ISPHT 2011
T2 - IASTED International Symposia on Imaging and Signal Processing in Healthcare and Technology, ISPHT 2011
Y2 - 16 May 2011 through 18 May 2011
ER -