Electroencephalography complexity in infantile spasms and its association with treatment response.

Abstract Objective To investigate the potential of EEG multiscale entropy and complexity as biomarkers in infantile spasms. Methods We collected EEG data retrospectively from 16 newly diagnosed patients, 16 age- and gender-matched healthy controls, and 15 drug-resistant patients. The multiscale entropy (MSE) and total EEG complexity before anti-epileptic drug (AED) treatment, before adrenocorticotropic hormone (ACTH) treatment, 14 days after ACTH therapy, and after 6 months of follow-up were calculated. Results The total EEG complexity of 16 newly diagnosed infantile spasms patients was lower than the 16 healthy controls (median [IQR]: 351.5 [323.1–388.1] vs 461.6 [407.7–583.4]). The total EEG complexity before treatment was higher in the six patients with good response to AED than the 10 patients without response (median [IQR]: 410.0 [388.1–475.0] vs 344.5 [319.6–352.0]). The total EEG complexity before and after 14-days of ACTH therapy was not different between 13 ACTH therapy responders and nine non-responders. After 6-months follow-up, the total EEG complexity of ACTH therapy responders were higher than non-responders (median [IQR]: 598.5 [517.4–623.3] vs 448.6 [347.1–536.3]). Conclusions The total EEG complexity before AED and 6 months after ACTH are associated with spasm-freedom. Significance The total EEG complexity is a potential biomarker to predict and monitor the treatment effect in infantile spasms.