Brain morphometry: Alzheimer’s disease

Brains suffering from Alzheimer’s disease show pronounced morphological modifications, with ample volumetric reduction of neural tissue. While particularly visible during the most severe disease stages, these changes are more subtle at the prodromal stage, which is the moment when a clinical diagnosis should be ideally reached. A large body of research has tried to disentangle the nature of such modifications, modeling the regional anatomical variability observed at various disease stages in samples and cohorts, implementing a number of different methodological avenues. The result is a complex picture in which brain morphology is not exclusively affected by disease processes, but is also under the influence of a large series of additional variables, which all contribute to the resulting phenotype via a tight network of multiple biological mechanisms. As a consequence, the study of morphological changes in AD highlights a sensible lack of clinical specificity. Despite these limitations, however, a large body of publications has highlighted the importance of brain morphology for the characterization of different phenotypic expressions of this disease and for the quantification of treatment effects.