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Complexity of Multi-Channel Electroencephalogram Signal Analysis in Childhood Absence Epilepsy.

Weng WC, Jiang GJ, Chang CF, Lu WY, Lin CY, Lee WT, Shieh JS - PLoS ONE (2015)

Bottom Line: The entropy values in the pre-ictal state were significantly higher than those in the ictal state.The MSE revealed more differences in analysis compared to the SamEn.In conclusion, MSE analysis is better than SamEn analysis to analyze complexity of EEG, and CI can be used to investigate the functional brain changes during absence seizures.

View Article: PubMed Central - PubMed

Affiliation: Department of Life Science, National Taiwan University, Taipei, Taiwan; Department of Pediatrics, National Taiwan University Hospital, Taipei, Taiwan; Department of Pediatrics, College of Medicine, National Taiwan University, Taipei, Taiwan; Department of Pediatric Neurology, National Taiwan University Children's Hospital, Taipei, Taiwan.

ABSTRACT
Absence epilepsy is an important epileptic syndrome in children. Multiscale entropy (MSE), an entropy-based method to measure dynamic complexity at multiple temporal scales, is helpful to disclose the information of brain connectivity. This study investigated the complexity of electroencephalogram (EEG) signals using MSE in children with absence epilepsy. In this research, EEG signals from 19 channels of the entire brain in 21 children aged 5-12 years with absence epilepsy were analyzed. The EEG signals of pre-ictal (before seizure) and ictal states (during seizure) were analyzed by sample entropy (SamEn) and MSE methods. Variations of complexity index (CI), which was calculated from MSE, from the pre-ictal to the ictal states were also analyzed. The entropy values in the pre-ictal state were significantly higher than those in the ictal state. The MSE revealed more differences in analysis compared to the SamEn. The occurrence of absence seizures decreased the CI in all channels. Changes in CI were also significantly greater in the frontal and central parts of the brain, indicating fronto-central cortical involvement of "cortico-thalamo-cortical network" in the occurrence of generalized spike and wave discharges during absence seizures. Moreover, higher sampling frequency was more sensitive in detecting functional changes in the ictal state. There was significantly higher correlation in ictal states in the same patient in different seizures but there were great differences in CI among different patients, indicating that CI changes were consistent in different absence seizures in the same patient but not from patient to patient. This implies that the brain stays in a homogeneous activation state during the absence seizures. In conclusion, MSE analysis is better than SamEn analysis to analyze complexity of EEG, and CI can be used to investigate the functional brain changes during absence seizures.

No MeSH data available.


Related in: MedlinePlus

The variations of complexity index (CI) from epoch a to f in patient 1.Each epoch represented mean CI value calculated from 5 sec EEG data points from the pre-ictal state to the ictal state. Changes in mean CI were more prominent over the frontal and central areas during ictal state. The top of the figure was the front of the head and the bottom of the figure was the occipital area of the head. Blue color represented low CI value while red color represented high CI value.
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pone.0134083.g006: The variations of complexity index (CI) from epoch a to f in patient 1.Each epoch represented mean CI value calculated from 5 sec EEG data points from the pre-ictal state to the ictal state. Changes in mean CI were more prominent over the frontal and central areas during ictal state. The top of the figure was the front of the head and the bottom of the figure was the occipital area of the head. Blue color represented low CI value while red color represented high CI value.

Mentions: In addition, even in the pre-ictal state, the correlation between different seizures in the same patient was low. In order to display variations of CI more intuitively, the changes of CI in different time periods from pre-ictal states to ictal states were plotted from Patient 1 (Fig 6). From this figure, a more intuitive way of investigating the CI variation in different time periods was attained to determine the network dysfunction of the brain. The CI values were dramatically reduced during the ictal state, especially over the frontal and central areas.


Complexity of Multi-Channel Electroencephalogram Signal Analysis in Childhood Absence Epilepsy.

Weng WC, Jiang GJ, Chang CF, Lu WY, Lin CY, Lee WT, Shieh JS - PLoS ONE (2015)

The variations of complexity index (CI) from epoch a to f in patient 1.Each epoch represented mean CI value calculated from 5 sec EEG data points from the pre-ictal state to the ictal state. Changes in mean CI were more prominent over the frontal and central areas during ictal state. The top of the figure was the front of the head and the bottom of the figure was the occipital area of the head. Blue color represented low CI value while red color represented high CI value.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4526647&req=5

pone.0134083.g006: The variations of complexity index (CI) from epoch a to f in patient 1.Each epoch represented mean CI value calculated from 5 sec EEG data points from the pre-ictal state to the ictal state. Changes in mean CI were more prominent over the frontal and central areas during ictal state. The top of the figure was the front of the head and the bottom of the figure was the occipital area of the head. Blue color represented low CI value while red color represented high CI value.
Mentions: In addition, even in the pre-ictal state, the correlation between different seizures in the same patient was low. In order to display variations of CI more intuitively, the changes of CI in different time periods from pre-ictal states to ictal states were plotted from Patient 1 (Fig 6). From this figure, a more intuitive way of investigating the CI variation in different time periods was attained to determine the network dysfunction of the brain. The CI values were dramatically reduced during the ictal state, especially over the frontal and central areas.

Bottom Line: The entropy values in the pre-ictal state were significantly higher than those in the ictal state.The MSE revealed more differences in analysis compared to the SamEn.In conclusion, MSE analysis is better than SamEn analysis to analyze complexity of EEG, and CI can be used to investigate the functional brain changes during absence seizures.

View Article: PubMed Central - PubMed

Affiliation: Department of Life Science, National Taiwan University, Taipei, Taiwan; Department of Pediatrics, National Taiwan University Hospital, Taipei, Taiwan; Department of Pediatrics, College of Medicine, National Taiwan University, Taipei, Taiwan; Department of Pediatric Neurology, National Taiwan University Children's Hospital, Taipei, Taiwan.

ABSTRACT
Absence epilepsy is an important epileptic syndrome in children. Multiscale entropy (MSE), an entropy-based method to measure dynamic complexity at multiple temporal scales, is helpful to disclose the information of brain connectivity. This study investigated the complexity of electroencephalogram (EEG) signals using MSE in children with absence epilepsy. In this research, EEG signals from 19 channels of the entire brain in 21 children aged 5-12 years with absence epilepsy were analyzed. The EEG signals of pre-ictal (before seizure) and ictal states (during seizure) were analyzed by sample entropy (SamEn) and MSE methods. Variations of complexity index (CI), which was calculated from MSE, from the pre-ictal to the ictal states were also analyzed. The entropy values in the pre-ictal state were significantly higher than those in the ictal state. The MSE revealed more differences in analysis compared to the SamEn. The occurrence of absence seizures decreased the CI in all channels. Changes in CI were also significantly greater in the frontal and central parts of the brain, indicating fronto-central cortical involvement of "cortico-thalamo-cortical network" in the occurrence of generalized spike and wave discharges during absence seizures. Moreover, higher sampling frequency was more sensitive in detecting functional changes in the ictal state. There was significantly higher correlation in ictal states in the same patient in different seizures but there were great differences in CI among different patients, indicating that CI changes were consistent in different absence seizures in the same patient but not from patient to patient. This implies that the brain stays in a homogeneous activation state during the absence seizures. In conclusion, MSE analysis is better than SamEn analysis to analyze complexity of EEG, and CI can be used to investigate the functional brain changes during absence seizures.

No MeSH data available.


Related in: MedlinePlus