Nearly 45 years after the publication of Rebeiz's initial series,1 clinical definitions of corticobasal syndrome (CBS) remain controversial, and universally accepted criteria are lacking. One source of disagreement, evident since the earliest case reports,1 2 is a divide between criteria that emphasise the movement disorder and those that give equal weight to cognitive symptoms. This division is highlighted in the paper by Mathew et al,3 who applied three sets of published criteria to 40 consecutive CBS patients seen in a combined movement disorders–cognitive clinic. The criteria differed primarily in the approach to early cognitive dysfunction, which was considered an exclusion in one set of criteria,4 primarily a supportive feature in the second5 and was weighted equally …