Beschreibung:
<jats:title>Summary</jats:title><jats:sec><jats:title>Objective</jats:title><jats:p>In previous studies, we showed an altered overnight decrease of non–rapid‐eye‐movement (<jats:styled-content style="fixed-case">NREM</jats:styled-content>) sleep slow waves in children with encephalopathy related to status epilepticus during sleep (<jats:styled-content style="fixed-case">ESES</jats:styled-content>). Here, we test the hypothesis that these alterations renormalize after remission of <jats:styled-content style="fixed-case">ESES</jats:styled-content>. Because overnight decrease of slow waves has been linked to brain recovery and cognition, we investigate whether cognitive outcome is related to overnight changes of slow waves.</jats:p></jats:sec><jats:sec><jats:title>Methods</jats:title><jats:p>We performed a retrospective analysis of longitudinal overnight<jats:styled-content style="fixed-case"> electroencephalography (EEG</jats:styled-content>) in 10 patients with idiopathic <jats:styled-content style="fixed-case">ESES</jats:styled-content>. Automated slow wave detection and calculation of slope of slow waves during the first and last hour of <jats:styled-content style="fixed-case">NREM</jats:styled-content> sleep were employed. Intraindividual comparisons were undertaken of the slope during active phase and after remission of <jats:styled-content style="fixed-case">ESES</jats:styled-content>, and between patients after remission of <jats:styled-content style="fixed-case">ESES</jats:styled-content> and healthy controls. Explorative analysis of the relationship between slow wave slope and cognitive outcome was performed.</jats:p></jats:sec><jats:sec><jats:title>Results</jats:title><jats:p>The slope of slow waves did not decrease significantly across the night during active <jats:styled-content style="fixed-case">ESES</jats:styled-content>, particularly at the spike focus. After remission of <jats:styled-content style="fixed-case">ESES</jats:styled-content>, the slope decreased significantly overnight. Compared to controls, there was no difference in overnight slope decrease. Association between slope and neuropsychological outcome showed best cognitive outcome after remission in those children (n = 3) who showed some degree of slope decline during active <jats:styled-content style="fixed-case">ESES</jats:styled-content>.</jats:p></jats:sec><jats:sec><jats:title>Significance</jats:title><jats:p>This study provides evidence that alterations of overnight changes of <jats:styled-content style="fixed-case">NREM</jats:styled-content>‐sleep slow waves during active <jats:styled-content style="fixed-case">ESES</jats:styled-content> are reversible when <jats:styled-content style="fixed-case">ESES</jats:styled-content> resolves, and that the severity of neuropsychological compromise might be related to the extent of slow wave impairment during <jats:styled-content style="fixed-case">ESES</jats:styled-content>. Our findings suggest that analysis of slow waves might serve as a prognostic factor regarding cognitive outcome. <jats:styled-content style="fixed-case">ESES</jats:styled-content> may serve as disease model of pathologic slow wave sleep and our results might be expanded to epilepsies with spike wave activation in slow wave sleep not only in children but also in adults.</jats:p></jats:sec>