Authors :
Presenting Author: Ana Moreno Chaza, BS – Children's National Hospital
Sonya Leikin, BS – Children's National Hospital
Xiaotong Li, BS – Children's National Hospital
Priyanka Venkata Sita Illapani, MSc – Children's National Hospital
Hua Xie, PhD – Children's National Hospital
William Gaillard, MD – Children's National Hospital
Madison Berl, PhD – Children's National Hospital
Alena Stasenko, PhD – UC San Diego
Leigh Sepeta, PhD – Children's National Hospital
Rationale:
Language lateralization patterns for bilingual individuals with focal epilepsy depend on both seizure onset and timing of second language (L2) acquisition. In a previous adult study, first language (L1) was supported bilaterally regardless of seizure focus, while their second language was more likely to shift contralaterally to the seizure focus, particularly when seizure onset coincides with second language acquisition. These findings suggest that L2 may be more flexible and adaptive to neurological disruption than L1 (Stasenko et al., 2025). In contrast, concordance has been found in L1 and L2 in pediatric patients (Goldstein et al., 2025). We aim to examine these discrepancies in language lateralization in bilingual and monolingual epilepsy pediatric patients.
Methods:
We examined language lateralization in thirty-two epilepsy patients; 7 bilingual Spanish/English, 9 monolingual Spanish-speaking, and 16 monolingual English-speaking patients. All bilingual patients acquired Spanish as their L1 and English as their L2. Epilepsy patients were scanned on a 3.0 Tesla General Electric scanner. All participants underwent fMRI during an age-adjusted language task (auditory description decision task; ADDT). We conducted ANOVA analyses to examine differences in language lateralization indices (LI) across groups (monolingual Spanish, monolingual English, and bilingual patients). Within the bilingual group, a repeated-measures ANOVA was used to compare LI values between the ADDT Spanish and ADDT English conditions. In addition, Cohen’s kappa analysis was performed to assess concordance in lateralization between ADDT Spanish and ADDT English tasks in bilingual patients.
Results:
For IFG and WA, all groups demonstrated left lateralization both with linear LI values and categorical LI classification (see Table). For MFG, lateralization was more varied with left, right, and bilateral lateralization (see Table). We found no group differences between the three language groups in the brain areas (IFG, WA, MFG; p’s< 0.23). Although the average LI for the monolingual English group appeared more left lateralized than the monolingual Spanish and bilingual group for IFG and WA, this was not statistically significant; we will add more patients and see if this pattern is consistent. We used repeated measure ANOVA to examine differences between L1 and L2 in the bilingual group for IFG, WA and MFG, and found no statistical differences between L1 and L2 (all p’s>0.24). In fact, L1 and L2 were concordant across all areas with IFG (κ=1; p=0.01), WA (κ=0.42; p=0.03), and MFG (κ=0.73; p=0.01).
Conclusions:
Our findings show strong L1–L2 concordance in bilinguals and primarily left lateralization across regions, consistent with Goldstein et al. (2025) but differing from Stasenko et al. (2025), who found more variable patterns in adults. Future work will expand the sample and incorporate seizure characteristics.
Funding:
This work was partially supported by NICHD P50 HD105328.