Alexandra Schoenberger
University of Cincinnati College of Medicine
Background: Epilepsy has previously been implicated in the development of autism spectrum disorder (ASD) in the setting of Tuberous Sclerosis Complex (TSC). However, the role of language in this relationship is unclear and the specific relationship between ASD, epilepsy, and language development in this population has not been well-studied. Our objectives are to identify language predictors of ASD, evaluate the impact of epilepsy as a covariate on language development, and evaluate the relationship between epilepsy, language development, and development of ASD. Methods: This study included children ages 0-36 months with TSC who were enrolled in the TSC Autism Center of Excellence Research Network (TACERN), a multi-center, prospective observational study to identify biomarkers of ASD. Developmental assessments, including language-specific measures, were administered longitudinally, and outcome was assessed at 24 and 36 months of age. The Mullen Scales of Early Learning (MSEL), Vineland Adaptive Behavior Scales (VABS), and Preschool Language Scales, 5th Edition (PLS5) were used to assess patients’ language skills. The Autism Diagnostic Observation Scale-2 (ADOS-2) was used as a diagnostic classification system in order to standardize our outcome variable. Results: By 12 months, all MSEL language variables and several PLS-5 and VABS variables significantly predicted positive ADOS-2 classification at 24 and/or 36 months. By 18 months and beyond, all language variables significantly predicted a positive ADOS-2 classification. When controlling for nonverbal measures of development on the MSEL (fine motor and visual reception), communication variables were no longer significant. The only exception was at 24 months, where receptive language on the MSEL (p=0.01), interpersonal relationships on the VABS (p=0.01), and auditory comprehension (p=0.02), and total language score (p=0.03) on the PLS5 remained significant. Age at seizure onset positively correlated with language scores in that later seizure onset correlated with an increase in communication variables on the MSEL, VABS, and PLS5. Likewise, a higher seizure frequency negatively correlated with communication scores at 12 months and beyond. Conclusion: Analysis of language variables and epilepsy characteristics from 6-36 months and ADOS classification at 24 and 36 months revealed significant relationships between all three variables. While the specific nature of the relationships needs further resea