Word list and story recall elicit different patterns of memory deficit in patients with Alzheimer's disease, frontotemporal dementia, subcortical ischemic vascular disease, and lewy body dementia

Background: Different roles have been attributed to mesio-temporal areas and frontal lobes in declarative memory functioning, and qualitative differences have been observed in the amnesic symptoms due to pathological damage of these two portions of the central nervous system. Objective: The aim of the present study was to look for memory profiles related to pathological involvement in the temporal and frontal structures in patients with different dementia syndromes on word-list and prose memory tasks. Methods: 20 patients with Alzheimer's disease (AD), 20 with frontal variant of FTD (fvFTD), 20 with subcortical ischemic vascular dementia (SIVD), and 20 with Lewy body dementia (LBD) and 34 healthy subjects (NCs) were submitted to word-list and prose memory tasks. Results: All groups performed similarly on both the immediate and delayed recall of the word-list. Conversely, AD patients performed worse than all the other dementia groups on the immediate prose recall. On delayed prose recall, AD patients performed worse than fvFTD and SIVD patients but similar to LBD patients. Differential scores between word-list and prose tests were minimal in the AD group and very pronounced in fvFTD and SIVD groups. Conclusion: The combined use of the prose and word-list tasks evidenced a 'mesio-temporal' memory profile in AD patients as opposed to a 'frontal' one in fvFTD and SIVD patients and a mixed profile in the LBD patients. In particular, a differential score between the two tests can be useful in differentiating AD patients from patients with other forms of dementia.