Cerebral cortical thickness and surface area in adolescent anorexia nervosa: Separate and joint analyses with a permutation-based nonparametric method.

Anna D Myrvang,Tor Endestad,Per M Aslaksen,Jan H Rosenvinge,Kristin Stedal,Øyvind Rø,Torgil R Vangberg

doi:10.1002/eat.23448

Abstract

Reduction in cerebral volume is often found in underweight patients with anorexia nervosa (AN), but few studies have investigated other morphological measures. Cortical thickness (CTh) and surface area (CSA), often used to produce the measure of cortical volume, are developmentally distinct measures that may be differentially affected in AN, particularly in the developing brain. In the present study, we investigated CTh and CSA both separately and jointly to gain further insight into structural alterations in adolescent AN patients. Thirty female AN inpatients 12-18 years of age, and 27 age-matched healthy controls (HC) underwent structural magnetic resonance imaging. Group differences in CTh and CSA were investigated separately and jointly with a permutation-based nonparametric combination method (NPC) which may be more sensitive in detecting group differences compared to traditional volumetric methods. Results showed significant reduction in in both CTh and CSA in several cortical regions in AN compared to HC and the reduction was related to BMI. Different results for the two morphological measures were found in a small number of cortical regions. The joint NPC analyses showed significant group differences across most of the cortical mantle. Results from this study give novel insight to areal reduction in adolescent AN patients and indicate that both CTh and CSA reduction is related to BMI. The study is the first to use the NPC method to reveal large structural alterations covering most of the brain in adolescent AN.

Highlights

Cerebral structural alterations are consistently found in acutely ill patients with anorexia nervosa (AN), and most frequently reported is cerebral volume reduction (Bomba et al, 2013; Fonville, Giampietro, Williams, Simmons, & Tchanturia, 2014; Frank, Shott, Hagman, & Yang, 2013; Gaudio et al, 2011; Mainz, Schulte-Ruther, Fink, HerpertzDahlmann, & Konrad, 2012; Seitz et al, 2015)
Previous findings in adult AN patients have been limited to smaller areas (Leppanen et al, 2019) or no cortical surface area (CSA) reduction (Miles et al, 2018), and our results may imply that adolescent patients are more affected
As suggested for adolescents with major depressive disorder (MDD), the reason for the surface area decrease in adolescent AN may be a delay in cortical maturation (Schmaal et al, 2016) as a result of illness debut in a critical period in brain development

Summary

Introduction

Cerebral structural alterations are consistently found in acutely ill patients with anorexia nervosa (AN), and most frequently reported is cerebral volume reduction (Bomba et al, 2013; Fonville, Giampietro, Williams, Simmons, & Tchanturia, 2014; Frank, Shott, Hagman, & Yang, 2013; Gaudio et al, 2011; Mainz, Schulte-Ruther, Fink, HerpertzDahlmann, & Konrad, 2012; Seitz et al, 2015). Cortical volume is often measured as the product of cortical surface area (CSA) and cortical thickness (CTh). These measures reflect two genetically and developmentally distinct measures with individual life span trajectories and different association with cognitive development and disorder (Fjell et al, 2015; Winkler et al, 2010). The combination of these two metrics may be imprecise as it does not account for the unique contribution of area and thickness (Panizzon et al, 2009). As CTh is steadily decreasing in adolescents, and CSA may still be expanding, the effect of AN may differ for CTh and CSA in adolescents

Methods

Results

Discussion

Conclusion