Frontotemporal dementia versus Alzheimer's disease: differential cognitive features

Frontotemporal dementia (FTD) is a common neurodegenerative dementia that can be difficult to distinguish clinically from Alzheimer's disease (AD). The differential distribution of pathology in FTD and AD predicts the presence of differential cognitive features on mental status examination. We compared 39 FTD patients with 101 AD patients on the Consortium to Establish a Registry in AD examination supplemented by cognitive areas from the Neurobehavioral Cognitive Status Examination. The FTD patients were diagnosed using noncognitive clinical and neuroimaging criteria and were comparable to the AD patients in terms of gender, educational level, and dementia severity ratings. The FTD patients performed significantly better than the AD patients on constructions and calculations. These findings were at the lower limits of normal for older normal controls and persisted after covarying for younger age and higher Mini-Mental Status Examination scores in the FTD group. In addition to personality and neuroimaging features, relatively preserved performance of elementary drawings and calculations in FTD suggests additional features for distinguishing FTD patients from comparably demented AD patients.