Influence of seizures on early development in tuberous sclerosis complex

- Infants with TSC who develop seizures early in life are more likely to exhibit developmental deficits by 24 months of age.
- Infantile spasms are most common in this population, occurring alone or in combination with focal seizures.
- Infantile spasms, higher seizure frequency, and early age of seizure onset correlate with poorer developmental outcome.
- Age of seizure onset has greater impact on developmental outcome by 24 months of age than seizure type or seizure frequency.

ObjectiveEpilepsy is commonly seen in Tuberous Sclerosis Complex (TSC). The relationship between seizures and developmental outcomes has been reported, but few studies have examined this relationship in a prospective, longitudinal manner. The objective of the study was to evaluate the relationship between seizures and early development in TSC.MethodsAnalysis of 130 patients ages 0-36 months with TSC participating in the TSC Autism Center of Excellence Network, a large multicenter, prospective observational study evaluating biomarkers predictive of autism spectrum disorder (ASD), was performed. Infants were evaluated longitudinally with standardized evaluations, including cognitive, adaptive, and autism-specific measures. Seizure history was collected continuously throughout, including seizure type and frequency.ResultsData were analyzed at 6, 12, 18, and 24 months of age. Patients without a history of seizures performed better on all developmental assessments at all time points compared to patients with a history of seizures and exhibited normal development at 24 months. Patients with a history of seizures not only performed worse, but developmental progress lagged behind the group without seizures. All patients with a history of infantile spasms performed worse on all developmental assessments at 12, 18, and 24 months. Higher seizure frequency correlated with poorer outcomes on developmental testing at all time points, but particularly at 12 months and beyond. Patients with higher seizure frequency during infancy continued to perform worse developmentally through 24 months. A logistic model looking at the individual impact of infantile spasms, seizure frequency, and age of seizure onset as predictors of developmental delay revealed that age of seizure onset was the most important factor in determining developmental outcome.ConclusionsResults of this study further define the relationship between seizures and developmental outcomes in young children with TSC. Early seizure onset in infants with TSC negatively impacts very early neurodevelopment, which persists through 24 months of age.