Quantitative detection of seizures with minimal-density EEG montage using phase synchrony and cross-channel coherence amplitude in critical care.

Seizures frequently occur in paediatric emergency and critical care, with up to 74% being sub-clinical seizures making detection difficult. Delays in seizure detection and treatment worsen the neurological outcome of critically-ill patients. Gold-standard seizure detections using multi-channels electroencephalograms (EEG) require trained clinical physiologists to apply scalp electrodes and highly specialised neurologists to interpret and identify seizures. In this study, we extracted phase synchrony and cross-channel coherence amplitude across 4 and 8 pre-selected scalp EEG signals. Binary classification is used to determine whether the signal segment is seizure or non-seizure, and the predictions were compared against the gold-standard seizure onset markings. The application of the algorithm on a cohort of forty routinely collected EEGs from paediatric patients showed an average accuracy of 77.2 % and 76.5% using 4 and 8 channels, respectively. Clinical Relevance- This work demonstrates the feasibility of seizure detection with pre-defined 4 and 8 EEG electrodes with an average accuracy of 77%. This means for the first time seizure detection is possible using an EEG montage that can be applied readily at the bedside independent of expert input.

Decreased brain coordinated activity in autism spectrum disorders during executive tasks: reduced long-range synchronization in the fronto-parietal networks.

Current theories of brain function propose that the coordinated integration of transient activity patterns in distinct brain regions is the essence of brain information processing. The behavioural manifestations of individuals with autism spectrum disorders (ASD) suggest that their brains have a different style of information processing. Specifically, a current trend is to invoke functional disconnection in the brains of individuals with ASD as a possible explanation for some atypicalities in the behaviour of these individuals. Our observations indicate that the coordinated activity in brains of children with autism is lower than that found in control participants. Disruption of long-range phase synchronization among frontal, parietal and occipital areas was found, derived from magnetoencephalographic (MEG) recordings, in high-functioning children with ASD during the performance of executive function tasks and was associated with impaired execution, while enhanced long-range brain synchronization was observed in control children. Specifically, a more significant prefrontal synchronization was found in control participants during task performance. In addition, a robust enhancement in synchrony was observed in the parietal cortex of children with ASD relative to controls, which may be related to parietal lobe abnormalities detected in these individuals. These results, using synchronization analysis of brain electrical signals, provide support for the contention that brains of individuals with autism may not be as functionally connected as that of the controls, and may suggest some therapeutic interventions to improve information processing in specific brain areas, particularly prefrontal cortices.