Optimizing seizure detection by quantitative EEG in paediatric refractory status epilepticus

@#Background & Objective: Continuous electroencephalography (cEEG) is valuable in the diagnosis and management of refractory status epilepticus (RSE) but requires intensive skilled interpretation. Density spectral array (DSA) is a quantitative analytic tool used to screen cEEG recordings for seizures. This study aims to determine the optimal amplitude setting and to compare the use of single-averagetrendgraph display and eight-trendgraph display in seizure detection with DSA. Methods: Five excerpts from pediatric cEEG recordings with RSE were identified. In Phase 1 of the study, each of 4 readers determined the DSA amplitude setting one most preferred for each excerpt, and marked all seizures in one excerpt using one’s preferred setting. Inter-rater agreement in seizure detection was measured. In Phase 2, readers marked all seizures in all excerpts, first using single-average-trendgraph display, and then using eight-trendgraph display after a wash-out period. Intra-rater agreement in seizure detection between the two display methods was calculated. Results: In Phase 1, DSA readers’ choice of preferred amplitude settings varied widely but inter-rater agreement in seizure detection was high. In Phase 2, seizure detection using single- and eight-trendgraph displays showed high agreement with each other and, where they disagreed, single-average-trendgraph was more sensitive. Additionally, low seizure-to-background amplitude ratio in EEG recordings was associated with worse detection sensitivity/specificity. Conclusions: DSA amplitude settings do not affect seizure detection. Single-trendgraph display is comparable to eight-trendgraph display in screening cEEG for seizures. Seizure detection with DSA performs better in cEEG recordings with high seizure-to-background amplitude ratio.

An unusual case of infant seizures with anaphylaxis to wheat

Wheat allergy is one of the commonest food allergies in childhood and it typically presents with IgE mediated reactions, including anaphylaxis. Seizures are not typically reported to be a direct manifestation of anaphylaxis, though it can occur secondary to hypoxia following significant haemodynamic compromise. We describe a case of a previously well infant, who presented with anaphylactic shock to wheat and responded well to the initial management, but subsequently developed a cluster of brief generalised tonic clonic seizures without any ongoing haemodynamic instability. The tryptase level that was performed at 4–5 hours post reaction was raised at 49.1 µg/L. Skin prick test to wheat, wheat specific IgE, the omega-5 gliadin IgE were positive. Extensive work-up was performed to look for an underlying cause of seizures and all returned negative. To our knowledge, this is the first case report describing an unusual presentation of multiple seizures in a young infant, in association with an anaphylactic episode. In the absence of any other seizure provoking factor and underlying cause, we believe the association is more likely causative than coincidental.