GTC evolution occurs most frequently out of sleep and in older patients. Our results may assist in seizure prediction, individualized treatment patterns, and potentially complication and SUDEP prevention.

SUMMARYPurpose: Epileptic spasms are seizures that occur predominantly in children and are characterized by clusters of brief axial movements. Epileptic spasms may occur in the context of a variety of syndromes. Previous research has found that epileptic spasms occur in a sleep/wake and diurnal rhythm. The purpose of this study was to identify these patterns in different age groups. Methods: Charts of 2,021 patients with epilepsy undergoing video-electroencephalography (EEG) monitoring over a 10-year period were reviewed for presence of epileptic spasms and analyzed for their occurrence during the day (6 a.m. to 6 p.m.) or night, out of wake or sleep, and in 3-h time-blocks throughout the day. Exact epileptic spasm time, EEG localization, and the presence or absence of magnetic resonance imaging lesion were also recorded. Patients were separated into two age groups: A ages 3 and under, and over age 3. Statistical analysis of seizure occurrence in time bins was carried out using binomial calculations. p-Values <0.05 were taken as significant. Using exact seizure times, a generalized linear mixed model of the Poisson-family with a square root link function was used to calculate mean seizure times. Age, as a binary variable, and time, as a categorical variable, was treated as fixed effect predictors, and individual effects were modeled as random effects. For comparison between the two age groups, over age 3 and under age 3, seizure times were transformed into circular variables. A circular analysis of variance test was used to assess for the difference in mean seizure time, assuming a von Mises distribution of the circle. Key Findings: We analyzed 219 clusters of epileptic spasms in 51 patients (15 girls; mean age 2.15 ± 2.22 years). Forty-two patients younger than 3 years of age had 163 seizures and nine patients older than 3 years had 56 seizures. Epileptic spasms occurred predominantly during wakefulness (p < 0.001) and during daytime (p < 0.001). Epileptic spasms occurred most frequently between 9 a.m. and noon (p < 0.05) and between 3 p.m. and 6 p.m. (p < 0.001). Patients without magnetic resonance imaging lesions had most seizures between 9 a.m. and noon (p < 0.01) and 3 p.m. and 6 p.m. (p < 0.001). Thirty-seven patients had 157 epileptic spasms (71.2%) with generalized EEG patterns and 14 patients had 62 epileptic spasms (28.8%) with focal EEG patterns. Generalized EEG seizures occurred more frequently than focal EEG seizures (p < 0.001). Following age stratification, patients younger than 3 years had most epileptic spasms between 9 a.m. and noon (p < 0.05) and 3 p.m. and -6 p.m. (p < 0.01) and patients older than 3 years had most epileptic spasms between 6 a.m. and -9 a.m. (p < 0.05) and a second peak between 3 p.m. and 6 p.m., although the difference was not statistically significant due to insufficient numbers. Using continuous time analysis, the mean seizure time in the under age 3 and the over age 3 groups was 2:24 p.m. and 11:40 a.m. Using a circular analysis of variance test, the difference between me...

Seizures can evolve sequentially into different clinical phases. For example, a seizure may start as an aura (first phase), then evolve into a tonic seizure (second phase), and evolve further into a generalized tonic-clonic semiology (third phase). It is currently unknown whether specific seizure evolutions cluster at particular times of the day and/or during sleep/wakefulness. We aimed to describe the distribution of the clinical evolution of seizures across time of day and sleep/wake state. We included all patients with at least two seizure phases admitted for long-term electroencephalogram monitoring during a 5 year period. Two-hundred-and-fifteen patients (866 seizures) presented with two different phases and 87 patients (324 seizures) evolved into a third clinical phase. During phase two, evolution into clonic seizures differed across time (p = 0.047) with peaks at 0-3 h and 6-9 h and during sleep (p < 0.001), evolution into automotor seizures peaked during wakefulness (p = 0.015), evolution into tonic seizures differed across time (p = 0.005) with peaks at 21-12 h and during sleep (p = 0.0119), and generalized tonic-clonic seizures peaked during sleep (p = 0.0067). Findings remained statistically significant after multivariable analysis adjusting, separately, for potential confounders (semiology of the first phase, age, gender, days in the long-term electroencephalographic monitoring unit, abnormal neuroimaging, number of antiepileptic medications, and seizure localization). During phase three, seizure evolutions followed the same pattern of distribution as during phase two but differences did not reach statistical significance. Our data demonstrate that the evolution of seizures into different phases cluster at specific times of day and at specific phases of the sleep/wakefulness cycle.