Asymmetric thinning of the cerebral cortex across the adult lifespan is accelerated in Alzheimer’s disease
James M. Roe, Didac Vidal‐Piñeiro, Øystein Sørensen, Andreas M. Brandmaier, Sandra Düzel, Héctor Alfredo Baptista González, Rogier Kievit, Ethan Knights, Simone Kühn, Ulman Lindenberger, Athanasia M. Mowinckel, Lars Nyberg, Denise C. Park, Sara Pudas, Melissa M. Rundle, Kristine B. Walhovd, Anders M. Fjell, René Westerhausen, The Australian Imaging Biomarkers and Lifestyle Flagship Study of Ageing, Colin L. Masters, Ashley I. Bush, Christopher Fowler, David Darby, Kelly Pertile, Carolina Restrepo, Blaine R. Roberts, Jo Robertson, Rebecca Rumble, Tim Ryan, Steven Collins, Christine Thai, Brett Trounson, Kate Lennon, Qiao‐Xin Li, Fernanda Yevenes Ugarte, Irene Volitakis, Michael Vovos, Rob Williams, Jenalle E. Baker, Alyce Russell, Madeline Peretti, Lidija Milicic, Lucy Lim, Mark Rodrigues, Kevin Taddei, Tania Taddei, Eugene Hone, Florence Lim, Shane Fernandez, Stephanie R. Rainey‐Smith, Steve Pedrini, Ralph N. Martins, James D. Doecke, Pierrick Bourgeat, Jürgen Fripp, Simon Gibson, Hugo Leroux, David G. Hanson, Vincent Doré, Ping Zhang, Samantha C. Burnham, Christopher C. Rowe, Victor L. Villemagne, Paul Yates, Sveltana Bozin Pejoska, Gareth Jones, David Ames, Elizabeth Cyarto, Nicola T. Lautenschlager, Kevin J. Barnham, Lesley Cheng, Andy Hill, Neil Killeen, Paul Maruff, Brendan Silbert, Belinda M. Brown, Hamid R. Sohrabi, Greg Savage, Michaël Vacher
Abstract
Aging and Alzheimer's disease (AD) are associated with progressive brain disorganization. Although structural asymmetry is an organizing feature of the cerebral cortex it is unknown whether continuous age- and AD-related cortical degradation alters cortical asymmetry. Here, in multiple longitudinal adult lifespan cohorts we show that higher-order cortical regions exhibiting pronounced asymmetry at age ~20 also show progressive asymmetry-loss across the adult lifespan. Hence, accelerated thinning of the (previously) thicker homotopic hemisphere is a feature of aging. This organizational principle showed high consistency across cohorts in the Lifebrain consortium, and both the topological patterns and temporal dynamics of asymmetry-loss were markedly similar across replicating samples. Asymmetry-change was further accelerated in AD. Results suggest a system-wide dedifferentiation of the adaptive asymmetric organization of heteromodal cortex in aging and AD.