These results further support the association between brain atrophy and the progression of neuronal tau pathology in PSP, as in other primary or secondary tauopathies.31,32 However, the presence of the thalamus in our staging scheme (stage 4), and the severity of its atrophy over the entire course of the disease, suggests that glial pathology also plays a role in the progression of atrophy in PSP-RS. This evidence concerns the gene MAPT and tauopathy.