Seizure Duration and EEG Correlates: New Study From the Netherlands

Out on Pubmed, from investigators in the Netherlands, is this paper:

Seizure duration predicts postictal electroencephalographic recovery after electroconvulsive therapy-induced seizures.

C M Pottkämper J, P A J Verdijk J, Stuiver S, Aalbregt E, Schmettow M, Hofmeijer J, van Waarde JA, J A M van Putten M.Clin Neurophysiol. 2023 Jan 26;148:1-8. doi: 10.1016/j.clinph.2023.01.008. Online ahead of print.PMID: 36773503

The abstract is copied below:

Objective: We aim to provide a quantitative description of the relation between seizure duration and the postictal state using features extracted from the postictal electroencephalogram (EEG).

Methods: Thirty patients with major depressive disorder treated with electroconvulsive therapy (ECT) were studied with continuous EEG before, during, and after ECT-induced seizures. EEG recovery was quantified as the spectral difference between postictal and baseline EEG using the temporal brain symmetry index (BSI). The postictal temporal EEG evolution was modeled with a single exponential. The parameters of the model, including the time constant τ, describe the change and speed of postictal EEG recovery. The change from baseline EEG at t = 60 minutes post-seizure (ΔBSI) was calculated from the exponential fit. Postictal clinical reorientation time (ROT) was clinically established. A multivariate generalized multi-level Bayesian model was estimated with seizure duration and ROT as predictors of τ and ΔBSI.

Results: EEG features of 290 seizures and postictal states were used for analyses. The model faithfully described the dynamics of the postictal EEG in nearly all patients. Seizure duration was associated with the recovery time constant, τ, and ΔBSI. ROT was associated with τ, but not with ΔBSI.

Conclusions: Longer seizures are associated with slower postictal EEG recovery and more enduring EEG changes compared to baseline.

Significance: Quantitative EEG allows objective assessment of the postictal state.

Keywords: Clinical reorientation time; Depression; Electroconvulsive therapy; Postictal EEG recovery; Temporal brain symmetry index.

The paper is here.

And from the text:

This study provides some interesting information about the postical ECT EEG: it quantifies the (obvious) correlation between stronger seizures and stronger brain effects. However, it is hard to take these data at face value when fully 45% of the cohort had severe postical agitation.  There is also some inexpert verbiage about ECT that detracts from enthusiasm for this report.