Neuroanatomy of dementia in Down Syndrome revealed using a voxel‐based morphometry approach to computed tomography

People with Down syndrome (DS) are more likely to develop Alzheimer’s disease than the general population, but comorbidities and variable intellectual disability complicate diagnosis and disease monitoring. Although neuroimaging may help elucidate the pathogenesis of dementia, studies using magnetic resonance imaging (MRI) in DS subjects with dementia are limited due to greater motion artefact in those with severe cognitive impairment. Computed tomography (CT) is faster, thus less impacted by motion, but poor tissue contrast makes analysis of cortical and subcortical changes difficult. In this study, we use CTseg, an algorithm able to robustly spatially normalise and segment CT scans, to analyse grey matter (GM) and white matter (WM) differences in 98 DS subjects with and without cognitive impairment due to dementia.