30336
Changes in Amygdala and Hippocampus Volumes Among Adolescents with Autism Spectrum Disorder over the Course of the PEERS® Social Skills Intervention

Oral Presentation
Friday, May 3, 2019: 1:42 PM
Room: 517A (Palais des congres de Montreal)
A. Arias1, A. Barrington2, A. J. McVey1, H. K. Schiltz1, A. D. Haendel3, B. Yund4, A. V. Van Hecke5, W. Krueger6 and M. Carlson7, (1)Marquette University, Milwaukee, WI, (2)Biomedical Engineering, Marquette University, Milwaukee, WI, (3)Speech-Language Pathology, Concordia University Wisconsin, Mequon, WI, (4)Psychology, University of Wisconsin Milwaukee, Milwaukee, WI, (5)Psychology, Marquette University, Milwaukee, WI, (6)Speech Pathology and Audiology, Marquette University, Milwaukee, WI, (7)Education, Marquette University, Milwaukee, WI
Background: Amygdala and hippocampus volume comparisons between adolescents with and without autism spectrum disorder (ASD) have been mixed (e.g., Groen et al., 2010; Schumann et al., 2004). Further study is needed to better understand these findings. Additionally, adolescents with ASD who receive a well-validated social skills intervention have demonstrated neurological changes, via EEG, coinciding with improvements in social behavior (Van Hecke et al., 2013). No known study, has examined volumetric change of brain structures in ASD over the course of such an intervention.

Objectives: 1) Compare amygdala and hippocampus volumes for groups of adolescents with and without ASD before intervention. 2) Examine changes in these regions across the Program for the Education and Enrichment of Relational Skills (PEERS; Laugeson & Frankel, 2010) using a randomized controlled trial (RCT).

Methods: Thirty-two male adolescents (23 ASD, 9 typically developing (TD)) aged 11-16 participated. See Table 1 for descriptive statistics and volume means. An RCT (experimental (EXP) vs. waitlist control (WL)) of PEERS® was conducted for the ASD group. Structural MRI scans were collected twice (before and after PEERS® for the EXP group) using a GE 3T scanner. Freesurfer Autorecon Processing (Fischl et al., 2002) was used for whole brain structural segmentation. MATLAB (The Mathworks, Inc, 2018) was employed to extract bilateral amygdala and hippocampus volumes.

Results: One-way ANOVAs revealed no significant difference between groups on amygdala or hippocampus volumes before intervention. Repeated measures MANOVAs for Time (pretest vs. posttest) by Group (EXP vs. WL vs. TD), revealed a Time by Group interaction for amygdala volume (Wilks’ Lambda = .48, F(8,72) = 3.95, p < .001). Univariate follow-up showed that the interaction effect was upheld for right and left amygdala volumes. Paired sample t tests demonstrated a decrease in right (t(15) = 2.97, p = .010) and left (t(15) = 4.43, p < .001) amygdala volumes in the EXP group across intervention; no significant changes were found for the WL group. Conversely, left amygdala volume increased for the TD group (t(8) = -3.31, p = .011) across time. No significant effects were found for hippocampus volumes. Table 2 shows the descriptive statistics, F values, and significance levels for the univariate follow-ups.

Conclusions: Significant decreases were uncovered for bilateral amygdala volumes for the adolescents with ASD who received the intervention, whilst no significant changes were found for those who did not. The PEERS® intervention, shown to improve social behavior (Laugeson et al., 2009), may contribute to changes in amygdala volume. Furthermore, these changes in brain structure and behavior may dynamically and transactionally contribute to maintained overall outcomes observed after PEERS® for adolescents with ASD. Significant increases uncovered in the left amygdala volume for the TD adolescents are likely due to a maturation effect, as left amygdala volume has shown increases in TD males during adolescence (Neufang et al., 2009). No significant changes were found for bilateral hippocampus volumes, thus social behaviors targeted by PEERS® may be centered in the amygdala.

See more of: Biomarkers 3
See more of: Biomarkers (molecular, phenotypic, neurophysiological, etc)