Quantitative interictal subdural EEG analyses in children with neocortical epilepsy
Eishi Asano1, Otto Muzik, Aashit Shah
1Department of Pediatrics, Children's Hospital of Michigan, Detroit, Michigan 48201, USA.
Insights
Quantitative interictal electroencephalography (EEG) data can predict seizure onset zones in children with intractable neocortical epilepsy. This method helps pinpoint seizure origins using spike frequency and amplitude analysis from subdural EEG recordings.
Area of Science:
- Neurology
- Neurophysiology
- Epileptology
Background:
- Intractable neocortical epilepsy in children presents diagnostic challenges.
- Accurate localization of seizure onset zones is crucial for effective treatment.
Purpose of the Study:
- To investigate the relationship between quantitative interictal subdural EEG data and visually defined ictal findings.
- To determine if interictal EEG data can predict ictal EEG onset zones in pediatric epilepsy.
Main Methods:
- Prolonged intracranial EEG recording in 13 children using 48-120 channel subdural electrodes.
- Automatic spike detection and frequency analysis of interictal EEG segments.
- Comparison of spike frequency, amplitude, and latency with ictal EEG assessments.
Main Results:
- High reproducibility of spike frequency patterns across EEG segments.
- Electrodes with highest spike frequency, amplitude, and leading spike correlated significantly with seizure onset.
- A 14% maximal spike frequency threshold showed 90% specificity and 77% sensitivity for seizure onset detection.
Conclusions:
- Quantitative interictal subdural EEG analysis is a reliable method for predicting ictal onset zones.
- This approach offers a valuable tool for localizing seizure origins in pediatric neocortical epilepsy.
Purpose:
We studied the relation between quantitative interictal subdural EEG data and visually defined ictal subdural EEG findings in children with intractable neocortical epilepsy, and determined whether interictal EEG data are predictive of ictal EEG onset zones.
Methods:
Thirteen children (aged 1.2-15.4 years) underwent prolonged intracranial EEG recording, using 48- to 120-channel subdural electrodes. Three distinct 10-min segments of the continuous interictal EEG recording were selected for each patient, and the spike frequency for each channel was determined by using an automatic spike-detection program. Subsequently the average spike frequency of each electrode was compared with ictal assessment (onset, spread, and no early ictal involvement). In addition, 50 distinct interictal spikes were averaged for each patient, and the amplitude and latency after the leading spike (averaged spike showing the earliest peak) were measured for each electrode and analyzed with respect to ictal EEG findings.
Results:
Reproducibility of the spike-frequency pattern derived from three 10-min segments was high (Kendall's W, 0.85 +/- 0.08). Electrodes showing the highest spike frequency, the highest spike amplitude, and the leading spike were found to be a part of the seizure onset in 13 of 13, 12 of 13, and 10 of 13 cases, respectively. There was significant correlation between ictal assessment and spike frequency as well as spike amplitude. A receiver operating characteristics analysis showed that a cutoff threshold at 14% of the maximal spike frequency resulted in a specificity of 0.90 and a sensitivity of 0.77 for the detection of seizure-onset electrodes.
Conclusions:
Quantitative interictal subdural EEG may predict ictal-onset zones in children with intractable neocortical epilepsy.
