Utility of Quantitative EEG for Seizure Detection in Adults

Abstract

Summary:Traditional review of EEG for seizure detection requires time and the expertise of a trained neurophysiologist; therefore, it is time- and resource-intensive. Quantitative EEG (qEEG) encompasses a variety of methods to make EEG review more efficient and allows for nonexpert review. Literature supports that qEEG is commonly used by neurophysiologists and nonexperts in clinical practice. In this review, the different types of qEEG trends and spectrograms used for seizure detection in adults, from basic concepts to clinical applications, are discussed. The merits and drawbacks of the most common qEEG trends are detailed. The authors detail the retrospective literature on qEEG sensitivity, specificity, and false alarm rate as interpreted by experts and nonexperts alike. Finally, the authors discuss the future of qEEG as a useful screening tool and speculate on the trajectory of future investigations in the field.

Electrographic Seizure Detection by Neuroscience Intensive Care Unit Nurses via Bedside Real-Time Quantitative EEG

“…Sensitivity of nonphysician interpretation of qEEG in other studies has ranged from 74% 22 to 87%, 21 and specificity has ranged from 38% 22 to 90%. 19,20,23 Thus, we find that our values are fairly consistent with the previous literature, which were done largely in retrospective studies. This sensitivity, specificity, and false alarm rate supports the practice of neuro-ICU nurse interpretation of qEEG in real time at the bedside as an effective screening tool for NCSE/NCS.…”

“…The false-negative seizure has only a subtle signature on left hemisphere rhythmicity spectrogram and amplitude-integrated EEG (red boxes), whereas the true-positive seizure has the classic flame appearance on rhythmicity spectrogram as well as upward deflections. 19,22 qEEG = quantitative EEG.…”

“…For example, asymmetry spectrogram is excellent at highlighting and emphasizing short, focal seizures, whereas most other trends are not. 19,30 Subsequent studies may consider including asymmetry spectrogram if this trend is borne out in clinical practice and future investigations. We also did not find that nurses with more neuro-ICU experience had statistically significantly better or worse accuracy, a question that was brought up in the previous prospective nurse study.…”

“…Quantitative EEG (qEEG) distills cEEG data into its salient features, allowing more rapid review by neurophysiologists and non-neurophysiologists. 14-19 In addition, several retrospective studies have shown promise for ICU nurse interpretation of qEEG as a screening tool for seizure detection in adults. 20-22…”

Neuromonitoring in the ICU – what, how and why?

“…EEG features are analyzed statistically and used in frequency-based (spectral) as well as spatial (topography, coherence, connectivity) interpretations. qEEG allows objective and efficient processing of large amounts of EEG data and may increase sensitivity to impending or ongoing neurological crises such as seizures and cerebral ischemia [20][21][22]. qEEG has become available through several commercial applications and is being gradually adopted in the ICU setting [23].…”