Large-scale analysis of structural brain asymmetries during neurodevelopment: Associations with age and sex in 4265 children and adolescents.
Kurth F., Schijven D., van den Heuvel OA., Hoogman M., van Rooij D., Stein DJ., Buitelaar JK., Bölte S., Auzias G., Kushki A., Venkatasubramanian G., Rubia K., Bollmann S., Isaksson J., Jaspers-Fayer F., Marsh R., Batistuzzo MC., Arnold PD., Bressan RA., Stewart SE., Gruner P., Sorensen L., Pan PM., Silk TJ., Gur RC., Cubillo AI., Haavik J., O'Gorman Tuura RL., Hartman CA., Calvo R., McGrath J., Calderoni S., Jackowski A., Chantiluke KC., Satterthwaite TD., Busatto GF., Nigg JT., Gur RE., Retico A., Tosetti M., Gallagher L., Szeszko PR., Neufeld J., Ortiz AE., Ghisleni C., Lazaro L., Hoekstra PJ., Anagnostou E., Hoekstra L., Simpson B., Plessen JK., Deruelle C., Soreni N., James A., Narayanaswamy J., Reddy JY., Fitzgerald J., Bellgrove MA., Salum GA., Janssen J., Muratori F., Vila M., Giral MG., Ameis SH., Bosco P., Remnélius KL., Huyser C., Pariente JC., Jalbrzikowski M., Rosa PG., O'Hearn KM., Ehrlich S., Mollon J., Zugman A., Christakou A., Arango C., Fisher SE., Kong X., Franke B., Medland SE., Thomopoulos SI., Jahanshad N., Glahn DC., Thompson PM., Francks C., Luders E.
Only a small number of studies have assessed structural differences between the two hemispheres during childhood and adolescence. However, the existing findings lack consistency or are restricted to a particular brain region, a specific brain feature, or a relatively narrow age range. Here, we investigated associations between brain asymmetry and age as well as sex in one of the largest pediatric samples to date (n = 4265), aged 1-18 years, scanned at 69 sites participating in the ENIGMA (Enhancing NeuroImaging Genetics through Meta-Analysis) consortium. Our study revealed that significant brain asymmetries already exist in childhood, but their magnitude and direction depend on the brain region examined and the morphometric measurement used (cortical volume or thickness, regional surface area, or subcortical volume). With respect to effects of age, some asymmetries became weaker over time while others became stronger; sometimes they even reversed direction. With respect to sex differences, the total number of regions exhibiting significant asymmetries was larger in females than in males, while the total number of measurements indicating significant asymmetries was larger in males (as we obtained more than one measurement per cortical region). The magnitude of the significant asymmetries was also greater in males. However, effect sizes for both age effects and sex differences were small. Taken together, these findings suggest that cerebral asymmetries are an inherent organizational pattern of the brain that manifests early in life. Overall, brain asymmetry appears to be relatively stable throughout childhood and adolescence, with some differential effects in males and females.