Total output and switching in category fluency successfully discriminates Alzheimer's disease from Mild Cognitive Impairment, but not from frontotemporal dementia

Quanti-qualitative components of the semantic verbal fluency test in cognitively healthy controls, mild cognitive impairment, and dementia subtypes

This study is aimed to evaluating the underlying cognitive strategies used during Semantic Verbal Fluency (SVF) performance and comparing the differences between cognitively healthy controls (CHC), amnestic and amnestic-multiple domain mild cognitive impairment (a-MCI and a-md-MCI), Alzheimer's disease (AD), Lewy body dementia (LBD), and behavioral variant frontotemporal dementia (bvFTD). The cross-sectional study comprised 236 participants involving 78 CHC individuals, 33 a-MCI and 48 a-md-MCI, 39 AD, 22 LBD, and 16 bvFTD patients. Scores differed significantly when comparing CHC with dementia groups, showing medium to large variances. The best components in distinguishing between CHC and the dementia groups were the SVF-Total score and SVF-Cluster Size variables. CHC showed different performance in the SVF-Cluster Size variable compared with a-md-MCI, AD, and bvFTD; whereas, in the SVF-Mean Cluster Size, CHC differed from MCI's, AD, and LBD. The switching component displayed smaller capacity to differentiate between the clinical groups. The effect size was large comparing AD with bvFTD (1.267) and medium comparing AD with LBD (0.689) using the SVF-Cluster Size variable, but small using the other variables for the comparisons between dementia groups. Quanti-qualitative examination of the SVF may provide a valuable clue in distinguishing CHC from MCI and different dementia subtypes.