Epileptic Spasms Relapse Is Associated with Etiology and Treatment, but Not Conventional Attributes of Post-treatment EEG
Abstract number :
3.24
Submission category :
4. Clinical Epilepsy / 4D. Prognosis
Year :
2022
Submission ID :
2205102
Source :
www.aesnet.org
Presentation date :
12/5/2022 12:00:00 PM
Published date :
Nov 22, 2022, 05:28 AM
Authors :
Emmi Deckard, BS – University of California, Los Angeles; Rujuta Sathe, BS – University of California, Los Angeles; David Tabibzadeh, BS – University of California, Los Angeles; Rajsekar Rajaraman, MD – University of California, Los Angeles; Hiroki Nariai, MD PhD – University of California, Los Angeles; Shaun Hussain, MD – University of California, Los Angeles
Rationale: Relapse after initially effective treatment of infantile epileptic spasms syndrome (IESS) is relatively common and associated with poor long-term outcomes. Limited data (Hayashi et al 2016; Ji et al 2019; LaGrant et al 2021) suggest that relapse is associated with epileptiform discharges or slowing on post-treatment EEG, genetic etiology, and response to a non-surgical therapy. In this study, we set out to replicate these reported associations simultaneously in a single large cohort.
Methods: Patients with IESS were identified using a database of all patients with video-EEG confirmed IESS at UCLA. We then identified the subset of patients with response to therapy (other than surgical resection) observed at UCLA and confirmed by video-EEG. Response was defined as resolution of epileptic spasms, without relapse for at least one month, and without hypsarrhythmia on follow-up video-EEG. Relapse was defined as the return of epileptic spasms, with or without hypsarrhythmia. EEG attributes were abstracted from reports in the electronic medical record. Time to relapse was evaluated using Cox proportional hazards regression.
Results: We identified 140 patients with IESS who responded to a non-surgical treatment. Among these children, with median follow-up of 32.6 months (interquartile range [IQR] 12.7 – 55.2), there were 30 cases of relapse (21%), which occurred a median of 6.7 months (IQR, 2.0 – 15.7) after initial response. On a bivariate basis, latency to relapse was associated with known etiology (hazard ratio [HR] = 7.4; 95%CI 1.8 – 30.9; P = 0.006) and response to vigabatrin (versus other treatment, namely hormonal therapy; HR = 2.7; 95%CI 1.3 – 5.6; P = 0.008). In contrast, latency to relapse was not associated with either (1) the presence, spatial distribution, and abundance (i.e., rare vs occasional vs frequent) of epileptiform discharges (all P > > 0.05), or (2) the presence and distribution (i.e., focal vs generalized) of slowing on EEG (all P > > 0.05).
Conclusions: This study supports prior observations linking relapse to etiology, but conflicts with prior studies suggesting that epileptiform activity or slowing predict relapse. The observation that vigabatrin is associated with relapse likely suggests that patients who achieved response with vigabatrin (often following hormonal therapy failure) may harbor more severe disease and higher risk of relapse. Further study is needed to clarify clinical and conventional EEG-based risk factors for relapse. Furthermore, there is a need to identify novel biomarkers of epileptic spasms relapse, potentially including computational EEG measures and serum markers of inflammation.
Funding: This study was accomplished with support from the Elsie and Isaac Fogelman Endowment, the John C. Hench Foundation, the Hughes Family Foundation, and the UCLA Children’s Discovery and Innovation Institute.
Clinical Epilepsy