Use of 3-D cortical morphometry for mapping increased cortical gyrification and complexity in Williams syndrome

In this paper, we describe the use of three different shape measures i.e., shape index, curvedness, and L₂ norm of mean curvature - to quantify cortical gyrification and complexity, thereby evaluating brain structural differences between individuals with Williams syndrome (WS) and healthy controls. Unlike traditional measures of gyrification, the proposed measures analyze the intrinsic geometry of the cortex in three-dimensional (3-D) space. We analyzed the local and global cortical folding patterns of 39 WS and 39 controls using these shape measures, showing increased gyrification in the cingulate, visual cortex, superior parietal lobule, and central sulcus regions (more pronounced in the left brain hemisphere), and increased cortical complexity in left temporal and left parietal lobes in WS. These findings agree with, and extend, previously published studies and may relate to the characteristic clinical and cognitive profiles of individuals with WS