Authors :
Presenting Author: Juan Toro Perez, MD, MSc – University of Ottawa
Sharon Whiting, MD, FRCPC – Epileptologist, Neurologist, Pediatrics, University of Ottawa; sarah Healy, MSc – Research Coordinator, Pediatrics, University of ottawa; erick sell, MD, – Epileptologist, Neurologist, Pediatrics, University of ottawa; Srinivas Bulusu, BSc – Neurophysiologist, Pediatrics, University of ottawa; Asif Doja, MD, FRCPC – Neurologist, Pediatrics, University of ottawa; daniela Pohl, MD, FRCPC – Neurologist, Pediatrics, University of ottawa; sarah Buttle, MD, FRCPC – Neurologist, Pediatrics, University of ottawa; Katherine Muir, MD, FRCPC – Epileptologist, Neurologist, Pediatrics, University of ottawa
Rationale:
Electrical status epilepticus during slow-wave sleep (ESES) is an age-dependent and self-limited epilepsy syndrome. It has onset in childhood and is characterized by cognitive and behavioral disturbances, with or without clinical seizures (1).
The International League Against Epilepsy defines typical electroencephalographic (EEG) findings of continuous epileptic activity as occupying at least 50% of non-rapid eye movement (NREM) sleep (2), usually expressed as a spike wave index (SWI). Using quantitative electroencephalography (QEEG) automated detection tools may save time, especially when reviewing larger epochs as well as make accurate and standardized diagnosis (4). In this study, we compare SWI measured using QEEG automated detection with standard methods of SWI calculation to look at outcomes post treatment of ESES.
Methods:
We conducted a retrospective analysis of patients with electrographic and clinical diagnosis of ESES between December 2012 and May 2023 with the objective to evaluate the evolution of SWI using standard methods described in the literature and QEEG-amplitude integrated EEG in high mode Persyst 13 software.
Results:
A total of 19 patients with the EEG and clinical diagnosis of ESES were included. Nine had SWI >85%. The mean age of the patients at seizure onset was 4.68 years (range: 0.25-12, SD±2.74); at ESES diagnosis was 6.12 years (range: 2.5-16, SD±3.03). Language (7/19) and cognitive impairment (7/19) were clinical manifestations most frequently associated. Seven patients had resolution of ESES after 4.28 years (range: 2-7, SD ±1.88). Confirmed diagnoses required epilepsy monitoring unit (9), ambulatory (5) and sleep deprived EEG (5). A total of 14 EEGs records were available for full analysis. Six patients were treated with the diazepam protocol and eight were treated with clobazam optimization/addition of ASM.
The highest spike wave index was seen during the first 100 seconds of N2/N3 in NREM sleep. Persyst analysis yielded slightly higher SWI counts overall compared to counting by hand. Three patients on diazepam protocol had resolution of ESES with 62% average SWI reduction after therapy. The other three patients treated with diazepam protocol had a lower 39% average SWI reduction and no resolution. A total of eight patients treated with clobazam optimization/addition of ASM did not have resolution of ESES.
Conclusions:
Of all the methods of calculating SWI, using the first 100 seconds of NREM sleep yielded the highest SWI. In this group of patients with ESES, treatment with diazepam protocol resulted in the best results based on EEG analysis and clinical response. Better initial response to diazepam protocol was associated with better long term outcome. Amplitude integrated EEG is an important new tool to aid in the EEG analysis of these patients.
Funding: No funding was given for this research.