A qualitative awake EEG score for the diagnosis of continuous spike and waves during sleep (CSWS) syndrome in self-limited focal epilepsy (SFE): A case-control study. (January 2021)

• Record Type: Journal Article
• Authors: Aeby, Alec; Santalucia, Roberto; Van Hecke, Audrey; Nebbioso, Andrea; Vermeiren, Justine; Deconinck, Nicolas; De Tiège, Xavier; Van Bogaert, Patrick
• Is Part Of: Seizure. Volume 84(2021)
• Page Start: 34
• Page End: 39
• Publication Date: 2021-01
• Subjects: Continuous spike and waves during sleep (CSWS) -- Electrical status epilepticus during sleep (ESES) -- Self-limited focal epilepsy (SFE) -- EEG wakefulness -- Epilepsy with centro-temporal spikes (ECTS) -- EEG score; Epilepsy -- Periodicals; Epilepsy -- Periodicals; Seizures -- Periodicals; Épilepsie -- Périodiques; Electronic journals; Electronic journals; 616.853
• DOI: 10.1016/j.seizure.2020.11.008
• Languages: English
• ISSNs: 1059-1311

Abstract

Highlights: Evaluation of the awake EEGs using an EEG score at the time of cognitive regression is diagnostic of EE-CSWS. A grade of ≥ 3 on the EEG score has a high correlation with EE-CSWS. The qualitative EEG score is better than traditional quantitative EEG indices in EE-CSWS diagnosis. Abstract: Purpose: To determine whether awake EEG criteria can differentiate epileptic encephalopathy with continuous spike and waves during sleep (EE-CSWS) at the time of cognitive regression from typical, self-limited focal epilepsy (SFE). Methods: This retrospective case-control study was based on the analysis of awake EEGs and included 15 patients with EE-CSWS and 15 age-matched and sex-matched patients with typical SFE. The EEGs were anonymised and scored by four independent readers. The following qualitative and quantitative EEG indices were analysed: slow-wave index (SLWI), spike-wave index (SWI), spike-wave frequency (SWF), long spike-wave clusters (CLSW) and EEG score (between grades 0 and 4). Sensitivity and specificity were assessed using receiver operating characteristic (ROC) curves and their reproducibility with a kappa test. Results: Based on a highly sensitive cut-off, EE-CSWS patients were 8.4 times more likely than those with SFE to have an SLWI > 6%, 15 times more likely to have an SWI > 10 % and six times more likely to have a CLSW of ≥ 1 s. There was substantial agreement between readers (with kappa values of 0.64, 0.69 and 0.67). EE-CSWS patients were 13 times more likely to have an SWF of > 11 % and 149 times more likely to have an EEG score of ≥ 3 than typical SFE patients. Agreement about these ratings was almost perfect (kappa 0.91 and 0.86). Conclusion: An EEG score of ≥ 3 on a 20-min awake EEG differentiates typical SFE from EE-CSWS at the time of cognitive regression, with good reliability across readers with different levels of expertise.