The Spike-Wave Index of the First 100 Seconds of Sleep Can Be a Reliable Scoring Method for Electrographic Status Epilepticus in Sleep.

Abstract

Electrical status epilepticus in sleep (ESES) is an electrographic pattern in which interictal epileptiform activity is augmented by the transition to sleep, with non-rapid eye movement sleep state characterized by near-continuous lateralized or bilateral epileptiform discharges. The aim of this study was to measure the reliability of the spike-wave index (SWI) of the first 100 seconds of sleep as a tool for the diagnosis of ESES. One hundred forty studies from 60 unique patients met the inclusion. Two neurophysiologists calculated the SWI of the first 100 seconds of spontaneous stage II non-rapid eye movement sleep. This was compared with the SWI of the first 5 minutes of non-rapid eye movement sleep and the cumulative SWI of three 5-minute bins of sleep. Agreement between the three SWI methods were analyzed using several statistical tools and methods. Using an SWI of 50% as a diagnostic cutoff, 57% of records had a diagnosis of ESES based on the first 100 seconds of sleep. Fifty-four percent of records had a diagnosis of ESES based on the method of using the SWI of three bins. This resulted in a diagnostic accuracy of 92%, sensitivity of 96%, and specificity of 88%. Positive predictive values of children diagnosed with ESES using the first 100 seconds of sleep, compared with 3 combined bins, was determined to be 90% and a negative predictive value was determined to be 95%. This analysis confirmed the diagnostic accuracy of using the SWI of the first 100 seconds of sleep and the cumulative total of three 5-minute bins.