Characterization of early partial seizure onset: Frequency, complexity and entropy

Abstract

Objective A clear classification of partial seizures onset features is not yet established. Complexity and entropy have been very widely used to describe dynamical systems, but a systematic evaluation of these measures to characterize partial seizures has never been performed. Methods Eighteen different measures including power in frequency bands up to 300Hz, Gabor atom density (GAD), Higuchi fractal dimension (HFD), Lempel-Ziv complexity, Shannon entropy, sample entropy, and permutation entropy, were selected to test sensitivity to partial seizure onset. Intracranial recordings from forty-five patients with mesial temporal, neocortical temporal and neocortical extratemporal seizure foci were included (331 partial seizures). Results GAD, Lempel-Ziv complexity, HFD, high frequency activity, and sample entropy were the most reliable measures to assess early seizure onset. Conclusions Increases in complexity and occurrence of high-frequency components appear to be commonly associated with early stages of partial seizure evolution from all regions. The type of measure (frequency-based, complexity or entropy) does not predict the efficiency of the method to detect seizure onset. Significance Differences between measures such as GAD and HFD highlight the multimodal nature of partial seizure onsets. Improved methods for early seizure detection may be achieved from a better understanding of these underlying dynamics.

Seizure localization using three-dimensional surface projections of intracranial EEG power

“…While some studies have investigated raw voltage mapping during ictal periods (Otsubo et al, 2001; Jouny and Bergey, 2012), most groups performed data pre-processing to assist in display of biologically relevant events. High frequency oscillation (HFO) is a commonly studied marker for epileptogenesis (Gupta et al, 2011; Jacobs et al, 2010; Schevon et al, 2009) and has previously been used to generate topographic movies of icEEG ictal rhythms (Akiyama et al, 2006).…”

Multiscale Lempel–Ziv complexity for EEG measures

“…Alzheimer patients show an abnormally low LZC (e.g., Hornero et al, 2009;Dauwels et al, 2011). It has been demonstrated that LZC is a reliable measure for detection of early seizure onsets (Jouny and Bergey, 2012). LZC has also been used to detect different levels of consciousness.…”

Ordinal Patterns, Entropy, and EEG

“…Approximate entropy has been applied in several cardiovascular studies (see for a review [16]), for quantifying the effect of anesthesia drugs on the brain activity [17][18][19], for discriminating sleep stages [20,21], for epileptic EEG analysis and epileptic seizures detection [22,23] and in other fields (see [24,25] for a review of applications). Applications of sample entropy have been given in several cardiovascular studies [9,26] (see for a review [16]), for analysis of EEG data from patients with Alzheimer's disease [27], for epileptic EEG analysis and epileptic seizures detection [2,28] and other applications (see [24,25,29] for a review).…”