==== Front Pediatr Neurol Briefs Pediatr Neurol Briefs 1043-3155 pedneurbriefs Pediatr Neurol Briefs Pediatric Neurology Briefs 1043-3155 2166-6482 1043-3155Pediatric Neurology Briefs Publishers Chicago, IL, USA PNB-34-10 10.15844/pedneurbriefs-34-10 Seizure Disorders Neurology Pediatrics Nervous System Diseases Child Development Brain Diseases Neurosurgery Child Infant Wearable EEG Device for Continuous Spike–Wave in Sleep Oguni Hirokazu MD1* 1 Department of Pediatrics, Tokyo Women's Medical University, Tokyo, Japan * Correspondence: Dr. Hirokazu Oguni, E-mail: oguni.hirokazu@twmu.ac.jp 02 12 2020 2020 34 10 10 05 3 2020 26 11 2020 Copyright: © 2020 The Author(s)2020This work is licensed under the Creative Commons Attribution 4.0 International License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Interictal spike quantification in continuous spike-wave of sleep (CSWS): clinical usefulness of a wearable EEG device Investigators from the Hospital Dona Estefânia, Escola Superior de Tecnologias e Saúde de Lisboa and Centro Hospitalar Psiquiátrico de Lisboa investigated 38 patients with continuous spike-wave of sleep (CSWS) syndrome. ESESCSWSSpike IndexWearable Ambulatory EEG ==== Body Investigators from the Hospital Dona Estefânia, Escola Superior de Tecnologias e Saúde de Lisboa and Centro Hospitalar Psiquiátrico de Lisboa investigated 38 patients with continuous spike-wave of sleep (CSWS) syndrome. A 10-20 montage long-term ambulatory electroencephalography (aEEG) and a wearable aEEG with two bipolar EEG channels simultaneously validate the latter's usefulness to quantify the spike index (SI) to analyze the EEG response to the treatments. The SI was digitally calculated every 10 minutes by semiautomatic template-match-spike search analysis compared to both aEEG. They also compared daily SI stability (three-consecutive night, N=4) and monthly SI stability (N=10) in individual patients and employed the SI obtained from averaging the maximum SI for each of the first four sleep cycles (avSI) for comparison to reduce variability. The wearable aEEG examinations were repeated up to 8 times per patient. The response to therapy using corticosteroids (n=10), sulthiame (n=7), and the ketogenic diet (n=3) was assessed by comparison of the avSI after therapy. As a result, corticosteroids most effectively reduced the SI among therapies, although sizeable individual variability in both the amount and time of onset of clinical responses. In conclusion, the wearable aEEG with two bipolar EEG channels, which are easily attached and tolerable for children, can provide accurate SI quantification repeatedly in clinical settings. [1] COMMENTARY. CSWS syndrome, also known as encephalopathy related to status epilepticus during slow sleep (ESES), is one of the most common epileptic encephalopathies of childhood [2]. In this syndrome, epileptic seizures themselves may be infrequent or even absent, but EEG demonstrates marked activation of spike-wave discharges during sleep. The latter EEG phenomenon is believed to cause cognitive/behavioral deterioration in this syndrome because it electrically affects cerebral function [2]. As CSWS has been observed before such deteriorations, it is essential to estimate the SI for early therapeutic intervention. In clinical practice, the SI has been evaluated by routine EEG examinations during naps or long-term EEG during hospitalization; however, both methods have limitations, i.e., difficult interpretation of the SI and expense of repeated examinations [3,4]. Thus, it is ideal to evaluate the SI using aEEG for 24 hours at home. However, the aEEG device currently available is expensive, complicated to attach, and also intolerable to wear for a long time for children. In this study, the authors developed the wearable aEEG device capable of recording with bipolar two channels and digitally quantifying the SI, which was demonstrated to be accurate by comparing the SI with that of the full 10-20 long-term aEEG. The semiautomatic template-match-spike search analysis they employed can plot the SI every 10 minutes during overnight sleep accurately and without difficulty [5]. In CSWS syndrome, the methods to determine the SI and its boundary to limit the CSWS definition (initially SI >85%) have remained major concerns among specialists [2-4]. In terms of its simplicity, cost, and unification of the methods to quantify the SI, the wearable aEEG in this study should be useful not only in clinical practice but also in CSWS syndrome studies. Disclosures The author has declared that no competing interests exist. ==== Refs References 1 Carvalho D Mendes T Dias AI Leal A Interictal spike quantification in continuous spike-wave of sleep (CSWS): clinical usefulness of a wearable EEG device Epilepsy Behav 2020 1 104 Pt A 106902 10.1016/j.yebeh.2020.106902 31991392 2 Tassinari CA Rubboli G Encephalopathy related to Status Epilepticus during slow Sleep: current concepts and future directions Epileptic Disord 2019 6 21 S1 82 7 10.1684/epd.2019.1062 31180330 3 Gardella E Cantalupo G Larsson PG Fontana E Bernardina BD Rubboli G EEG features in Encephalopathy related to Status Epilepticus during slow Sleep Epileptic Disord 2019 6 21 S1 22 30 10.1684/epd.2019.1054 31162114 4 Scheltens-de Boer M Guidelines for EEG in encephalopathy related to ESES/CSWS in children Epilepsia 2009 8 50 Suppl 7 13 7 10.1111/j.1528-1167.2009.02211.x 19682043 5 Peltola ME Palmu K Liukkonen E Gaily E Vanhatalo S Semiautomatic quantification of spiking in patients with continuous spikes and waves in sleep: sensitivity to settings and correspondence to visual assessment Clin Neurophysiol 2012 7 123 7 1284 90 10.1016/j.clinph.2011.12.001 22225651