Dementia with Lewy bodies presenting as frontotemporal dementia phenotype

We herein report two patients with dementia with Lewy bodies (DLB) presenting characteristic symptoms suggestive of the behavioural variant of frontotemporal dementia (bvFTD). Patient 1 presented behavioural and personality changes from the onset, such as restlessness, compulsive behaviours, and stereotypical speech. A neuroimaging study showed preferential frontal involvement, and this patient fulfilled the diagnostic criteria for bvFTD. However, 123I‐metaiodobenzylguanidine cardiac scintigraphy revealed a markedly lowered uptake, suggesting the diagnosis of possible DLB. Patient 2 fulfilled the criteria for probable DLB, but later presented bvFTD‐like symptoms similar to those in patient 1. These patients suggest that DLB can be a candidate for differential diagnosis of bvFTD in the clinical setting.