Meijer KA, et al. - The authors conducted this study to examine when and where connectivity changes developed and investigate their clinical and cognitive relevance across different multiple sclerosis (MS) stages. In late relapsing–remitting MS (RRMS), increased connectivity of the deep grey matter became apparent and further increased in secondary progressive MS (SPMS). The additive effect of cortical network degeneration (only observed in SPMS) could explain the sudden clinical deterioration characteristic to this phase of the disease.