Assessing Risk for Relapse among Children with Infantile Spasms Using the Based Score after ACTH Treatment: A Retrospective Study

Abstract

Introduction Even though adrenocorticotropic hormone (ACTH) demonstrated powerful efficacy in the initially successful treatment of infantile spasms (IS), nearly one-half of patients whose spasms were once suppressed experienced relapse. There is currently no validated method for the prediction of the risk of relapse. The Burden of Amplitudes and Epileptiform Discharges (BASED) score is an electroencephalogram (EEG) grading scale for children with infantile spasms. We sought to determine whether an association exists between the BASED score after ACTH treatment and relapse after initial response with ACTH. Methods Children with IS who achieved initial response after ACTH treatment were selected as the study subjects. Those who experienced relapse within 12 months after ACTH treatment were categorized as the relapse group, and those who did not were categorized as the non-relapse group. Their general clinical data and EEG data (using BASED scoring) after ACTH treatment were collected, and compared between groups. Cox proportional hazards models were fit to determine factors associated with relapse. Results A total of 64 children with IS were enrolled in the study, of which 37 (57.8%) experienced a relapse, and the median duration after ACTH treatment was 3 (1.5, 6) months. The BASED score was significantly higher in the relapse group than in the non-relapse group. Cox modeling demonstrated that BASED score was independently associated with relapse. The patients with a score greater than or equal to 3 showed a high rate (89.3%) of relapse. The relapse group had stronger, more stable EEG functional networks than the non-relapse group, and there were obvious correlations between BASED score and functional connectivity. Conclusion This study suggests the BASED score after ACTH treatment has potential value as a predictor for relapse after initial response. Children with IS who have a BASED score greater than or equal to 3 after the initial response of ACTH carry a high risk of relapse within 1 year. Supplementary Information The online version contains supplementary material available at 10.1007/s40120-022-00347-7.

EEG biomarkers for the diagnosis and treatment of infantile spasms

“…The BASED score has shown promise for predicting relapse. Among treatment responders, those with post-treatment BASED scores of 3 or higher showed a high rate (89%) of subsequent relapse ( 26 ). Similarly, smaller decreases in delta power and delta coherence following treatment among responders have been shown to indicate higher risk of relapse.…”

“…One study suggested that the BASED score can predict relapse after an initial response with ACTH therapy. Children with positive treatment outcomes and a BASED score > 3 (which may indicate that the epileptiform activity was not sufficiently and effectively controlled) had a higher risk of relapse within 1 year ( 26 ).…”

“…Of those that do initially respond, 20–33% will have a relapse of IS ( 24 , 25 ). In the case of ACTH therapy, the time to relapse can be anywhere from 5 days to 25 months after the completion of treatment ( 26 , 27 ). To date, there are no methods for robustly predicting long-term, sustained response or relapse.…”

Interrater and Intrarater Agreement of Epileptic Encephalopathy Among Electroencephalographers for Children with Infantile Spasms Using the Burden of Amplitudes and Epileptiform Discharges (BASED) EEG Grading Scale: Study Design and Statistical Considerations

“…If the BASED score is proven to have moderateto-perfect interrater and intrarater agreement, the clinico-electrographic remission of infantile spasms will be confirmable via a unified and standardized method. In some cases, the change in the BASED scores after adrenocorticotropic hormone (ACTH) or other treatments will provide clinicians with more information to adjust and individualize therapy [31]. In another example, though vigabatrin (VGB) is the firstline therapy for infantile spasms, previous studies have reported irreversible visual field defects, abnormal brain structure, and other side effects of this treatment [32][33][34] that are related to treatment duration.…”

Automatic BASED scoring on scalp EEG in children with infantile spasms using convolutional neural network

“…After modification and further validation, the 2021 version was published ( Mytinger et al, 2021 ). The BASED score has been widely used as a criterion for the evaluation of EEG in pre-treatment and post-treatment studies of patients with IS ( Wang et al, 2021 ; Yan et al, 2021 ; Wan et al, 2022 ). The definition of remission is that, for a pre-treatment score of 4 or 5, the score must improve to 3 or less; and for a pre-treatment score of 3, the score must improve to 2 or less.…”