Electroclinical Landscape of Infantile Epileptic Spasms Syndrome

To elucidate the electroclinical characteristics of infantile epileptic spasms syndrome (IESS) and to determine any potential association among these with underlying etiologies and response to therapy.

Sixty-eight, treatment-naive children with IESS underwent long-term video electroencephalogram (EEG) recording, which was used to characterize the semiology, ictal, and inter-ictal EEG patterns. Children were further followed up to assess electroclinical predictors of etiologies and short-term therapeutic response.

Of 68 children enrolled (69% boys), the median age at enrollment was 10.5 mo (IQR-8). Eighty-eight percent of children had flexor spasms, followed by mixed (7%) and extensor (4.4%). Asymmetrical spasms were noted in 17.6% children, and all of them had underlying structural etiology. Two children had the status of epileptic spasms. In the present cohort, authors recognized five distinct ictal EEG correlates of epileptic spasms; the frontocentral dominant slow wave was the most prevalent (32%), followed by the generalized slow-wave complex with superimposed fast rhythm in 29.4%. The occipital dominant slow wave complex was a peculiar pattern in 16%. The major underlying etiologies were hypoxic-ischemic brain injuries (36.7%) and neonatal hypoglycemic brain injuries (22%). Besides asymmetric spasms, authors could not identify any significant association among electroclinical characteristics, underlying etiologies and response to therapy in this study.

The electroclinical landscape of IESS is peculiar and diverse in developing countries. The presence of asymmetrical spasms indicated underlying structural etiology.