Lower insular cortical thickness and greater parietal surface area among adolescent females with low-weight avoidant/restrictive food intake disorder (ARFID)

Yaen Chen, BS Candidate

Massachusetts General Hospital – Research Assistant
CHEN_YAEN poster

Scientific Abstract

Background: The neural circuitry underlying Avoidant/Restrictive Food Intake Disorder (ARFID), a restrictive eating disorder unrelated to body image concerns, is not well understood. Studying the distribution of anatomical abnormalities over the entire cortical surface will aid in understanding ARFID pathophysiology.

Methods: In this study, we compare cortical thickness (CT) and surface area (SA) between low-weight (low-wt) females with ARFID and healthy controls (HC). We hypothesized differential CT/SA patterns in the orbitofrontal cortex (OFC) and anterior insula, both regions that are associated with reward processing. Using a cross-sectional study design, we processed T1-weighted scans from 49 females (aged 10-21 years, mean = 16.8 ± 3.34 years) diagnosed with low-wt ARFID (n=18) and HC (n=31) with an internal pipeline, which included visual quality control steps, outlier detection, and masking using multi-atlas brain segmentation. Next, we processed masked images using FreeSurfer7, and extracted mean CT and SA for the bilateral insular cortex, occipital, frontal, parietal, and temporal lobes. We assessed between-group differences (low-wt ARFID vs. HC) in bilateral cortical regions using multiple linear regression in R. Estimated total intracranial volume was included as a covariate in all models.

Results: We found a significant main effect of group on the right insula CT (F(1, 46)=4.88, p=0.032), such that individuals with low-wt ARFID had lower CT in the insular cortex compared to HC. We also observed a significant difference between groups in the left parietal lobe SA (F(1, 46) = 4.41, p = 0.041), with greater SA in low-wt ARFID compared to HC.

Conclusions: Given the role of the insular cortex as the primary taste cortex and the parietal lobe as a sensory integration region, further research will aid in determining whether structural abnormalities in the insula and parietal regions may contribute to disrupted taste processing in avoidant-restrictive eating.

 

Transcript

Hi everyone! My name is Yaen Chen, and I am a senior undergraduate Behavioral Neuroscience major with a minor in Data Science at Northeastern University. I’m excited to be sharing my work today at Harvard Psychiatry Day, and my poster is titled, “lower insular cortical thickness and greater parietal surface area among adolescent females with low weight avoidant-restrictive food intake disorder. ARFID is a restrictive eating disorder unrelated to body image concerns. Instead, individuals restrict their food due to a fear of sensory sensitivities, a lack of interest in eating or food, or avoidance due to fear of negative consequences. Individuals present with one or more ARFID presentation profiles, which often results in a low weight status. Cortical thickness and surface area are quantifiable characteristics of cortical gray matter that can be analyzed using brain MRIs. Cortical thickness alterations have been associated with the onset of psychopathology, and in an fMRI study, the orbital frontal cortex and insula were hyper-activated in ARFID participants while viewing food related images. In our study, we aimed to compare cortical thickness and surface area patterns between youth with low weight ARFID and healthy controls with a priori ROI analysis. We hypothesized differential cortical thickness and surface area patterns between low weight ARFID and healthy controls specifically in the insula based on previous work. For this study, we acquired 49 T1-weighted scans from females, including 18 low-weight females with ARFID and 31 healthy control females. The T1-weighted scans underwent visual quality control, skull stripping, outlier detection, and masking. Next, the masked images were processed using FreeSurfer 7 to extract cortical thickness and surface area measures for the bilateral insular cortex, occipital, frontal, parietal, and temporal lobes. For statistical analysis, we assessed between-group differences, so looking at low-weight ARFID versus healthy controls, in bilateral cortical regions using multiple linear regression in R. Age correlated with estimated total intracranial volume, so it was not included as a covariate, but eTIV was included as a covariate in all models. We found that for cortical thickness, individuals with low-weight ARFID had significantly lower cortical thickness in the right insular cortex compared to healthy control females. For surface area, we found that individuals with low weight ARFID had significantly greater surface area in the left parietal lobe compared to our healthy control group. To our knowledge, this is the first study to document structural brain abnormalities in low-weight ARFID, and results are especially interesting because the insular cortex is the primary taste cortex while the parietal lobe is a main sensory integration region. Further research is needed to determine whether the structural abnormalities in the insular and parietal regions contributes to disrupted taste processing in avoidant-restrictive eating. Thank you so much for listening to my presentation, and I’d like to thank all my co-authors and mentors for their support on this project.

research Areas

Authors

Yaen Chen, Felicia Petterway, BS, Clara O. Sailer, MD, Holly Carrington, BA, Laura M. Holsen, PhD, Nadia Micali, PhD, Kendra Becker, PhD, Madhusmita Misra, MD, Kamryn T. Eddy, PhD, Debra L. Franko, PhD, Elizabeth A. Lawson, MD, Jennifer J. Thomas, PhD, Amanda E. Lyall, PhD, Lauren Breithaupt, PhD

Principal Investigator

Lauren Breithaupt, PhD

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