Relationship of Head Circumference and Epilepsy Severity in Infants with Tuberous Sclerosis Complex

Tuberous sclerosis complex (TSC) is a rare genetic disorder, characterized by high incidence of seizures and tubers (benign cellular abnormalities that appear on brain imaging). Current literature reports an increased head circumference within the TSC population, but the implications, exact rate, or how big the increase is, remains unknown. We hypothesized that increased head circumference would correlate with epilepsy severity in infants with TSC. We examined clinical data from 121 infants diagnosed with TSC who were enrolled in the multi-site, prospective TSC autism center for excellence network (TACERN) study. We calculated each infant’s head circumference z-score from each study visit by comparing collected values with those reported by the World Health Organization of healthy child head circumference growth. The overall mean head circumference z-score across all study visits of all TACERN participants was 0.97 with no significant sex differences. The number of seizure types correlated with head circumference z-score are as follows: infants with no seizures had a mean z-score of 0.57, those with 1 seizure type had a mean z-score of 0.88, and those with 2 or more seizure types had a mean z-score of 1.31. Thus, our hypothesis was partially supported. This data suggests that a larger head circumference may serve as a biomarker for epilepsy in children diagnosed with TSC, enabling earlier treatment for epilepsy, and thus improved neurodevelopment.