Focal cortical presentations of Alzheimer’s disease

To determine the frequency of Alzheimer’s disease (AD) pathology in patients presenting with progressive focal cortical syndromes, notably posterior cortical atrophy (PCA), corticobasal syndrome (CBS), behavioural variant frontotemporal dementia (bvFTD), progressive non-fluent aphasia (PNFA) (or a mixed aphasia) and semantic dementia (SD); and to compare the age of onset, evolution and prognosis in patients with focal cortical presentations of AD versus more typical AD and those with non AD pathology. From a total of 200 patients with comprehensive prospective clinical and pathological data we selected 120:100 consecutive cases with focal cortical syndromes and 20 with clinically typical AD.Clinical files were reviewed blind to pathological diagnosis. Of the 100 patients with focal syndromes, 34 had AD as the primary pathological diagnosis with the followin