The Frontal Assessment Battery does not differentiate frontotemporal dementia from Alzheimer's disease

Background: An early differentiation of Alzheimer's disease ( AD) from frontotemporal dementia (FTD) is important, since these conditions are essentially different regarding prognosis and therapeutical approach. Until now, no single test is available which allows a reliable differentiation. The Frontal Assessment Battery (FAB) has been found to have good reliability in identifying an executive deficit in frontal syndromes and in extrapyramidal disorders. The ability of the FAB to distinguish AD from FTD in mildly demented patients is less clearly assessed. Methods: We compared FAB scores in a consecutive series of 33 FTD ( frontal variant) and 85 AD patients. Results: FAB global scores in the two groups were very similar, also when considering only mildly demented subgroups [ Mini Mental State Examination (MMSE) score >= 20; 20 FTD and 38 AD patients]. Considering FAB subscores, only the 'go-no go' subtest showed a significant difference, reflecting a poorer inhibitory motor control in AD patients. FAB scores in the two groups of patients correlated with global cognitive decline ( MMSE), and with executive and visuospatial test scores, showing good concurrent validity. Conclusion: The FAB does not differentiate patients with AD from those with FTD, like all other executive tests. However, it may be useful in the examination of executive function in AD, FTD and several other pathological conditions. Copyright (C) 2006 S. Karger AG, Basel.