Mixed dementia: Neglected clinical entity or nosographic artifice?

Clinical and pathological data show that Alzheimer's disease (AD) and vascular dementia (VaD) are the most prevalent types of dementia in the elderly. Medically speaking, mixed dementia (MxD) is a heterogenous disorder mostly referred to the coexistence of AD and VaD. The weight of vascular contribution to AD phenotype is nowadays matter of debate. Despite great efforts in the field of neurodegeneration and cerebrovascular disease, controversy over the exact nature of their relation still remains, hampering progress in the specialty and raising doubts about the MxD concept validity. Is MxD a neglected clinical entity or a nosographic artifice? Starting from the assumption that recent advances in dementia classification and diagnostic criteria make this a propitious time to set up preventive and therapeutic strategies, this narrative review and opinion paper summarizes the literature concerning the questioned etiopathogenic overlap between AD and VaD and challenges the traditional view of MxD as the mere co-occurrence of different pure forms of dementia.