Quantified EEG for the Characterization of Epileptic Seizures versus Periodic Activity in Critically Ill Patients.

Lorena Vega-Zelaya,Elena Martín Abad,Jesús Pastor

doi:10.3390/brainsci10030158

Lorena Vega-Zelaya, Elena Martín Abad + Show 1 more

Open Access

https://doi.org/10.3390/brainsci10030158

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Journal: Brain sciences	Publication Date: Mar 10, 2020
Citations: 7	License type: CC BY 4.0

Affiliation: Hospital Universitario de La Princesa

Abstract

Epileptic seizures (ES) are frequent in critically ill patients and their detection and treatment are mandatory. However, sometimes it is quite difficult to discriminate between ES and non-epileptic bursts of periodic activity (BPA). Our aim was to characterize ES and BPA by means of quantified electroencephalography (qEEG). Records containing either ES or BPA were visually identified and divided into 1 s windows that were 10% overlapped. Differential channels were grouped by frontal, parieto-occipital and temporal lobes. For every channel and window, the power spectrum was calculated and the area for delta (0–4 Hz), theta (4–8 Hz), alpha (8–13 Hz), and beta (13–30 Hz) bands and spectral entropy (Se) were computed. Mean values of percentage changes normalized to previous basal activity and standardized mean difference (SMD) for every lobe were computed. We have observed that BPA are characterized by a selective increment of delta activity and decrease in Se along the scalp. Focal seizures (FS) always propagated and were similar to generalized seizures (GS). In both cases, although delta and theta bands increased, the faster bands (alpha and beta) showed the highest increments (more than 4 times) without modifications in Se. We have defined the numerical features of ES and BPA, which can facilitate its clinical identification.

Highlights

Patients in intensive care units (ICU) usually have limited clinical neurological examination, either because of structural or functional altered conditions of the Central Nervous System (CNS) or due to the effects of drugs used for sedoanalgesia [1]
We have defined the numerical features of epileptic seizures (ES) and bursts of periodic activity (BPA), which can facilitate its clinical identification
When BPA were taken from the same patient, we used recordings from different days

Summary

Introduction

Patients in intensive care units (ICU) usually have limited clinical neurological examination, either because of structural or functional altered conditions of the Central Nervous System (CNS) or due to the effects of drugs used for sedoanalgesia [1]. A dynamical evolution of injury is commonly observed in critically ill patients, due to the occurrence of epileptic seizures (ES), status epilepticus (SE), apoptosis, vasospasm or other different brain insults [2,3,4]. In the ICU field, the qEEG has been applied to facilitate the interpretation of prolonged EEG recordings, as well as the identification of electrographic seizures [11,12,13,14]

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