Initial studies of whole lobe volumetric measures showed profound and global GM loss with ventricular expansion in COS (Gogtay, 2008; Rapoport et al., 1997; Rapoport et al., 1999; Rapoport & Inoff-Germain, 2000). Subsequent prospective analyses using finer-scale brain mapping techniques showed that the GM loss in COS progressed in a characteristic back-to-front (parieto-frontal-temporal) direction during adolescent years (P. M. Thompson et al., 2001). This is strikingly similar to the pattern of GM loss (maturation) seen during normal cortical development (Gogtay, Giedd et al., 2004), but abnormally accelerated. Taken together, the cortical GM loss in COS appears to be an exaggerated pattern of the normal brain development during adolescence and could reflect the lack of normal controls GM maturation (Schoop, Gardziella, & Muller, 1997; E. R. Sowell et al., 2001).
