About 25 years ago, the world of neurodegenerative diseases was dominated by a clear and intuitively appealing distinction. On one hand, there were dementias, disorders of cognition, in which patients could develop problems with memory, language, attention or orientation, but in which motor functions were assumed to be preserved. On the other hand, there were motor disorders, affecting movement but leaving cognition intact. Dementia and movement specialists rarely interacted; they attended different conferences, read different journals (or at least articles) and used different assessment tools. The division was stronger in the Anglo-Saxon countries than in Continental Europe, with its tradition of linking neurology and psychiatry.