Alzheimer’s disease and vascular disease: The clinical spectrum

Abstract

Abstract Background The terms Vascular Cognitive Impairment (VCI), Vascular Cognitive Disorder (VCD) and Vascular Contributions to Cognitive Impairment & Dementia (VCID) were introduced to emphasise the important contribution of vascular pathology to any severity of cognitive impairment, ranging from subjective cognitive decline and mild cognitive impairment (MCI) to dementia. Although vascular pathology and Alzheimer’s Disease (AD) is common in elderly individuals with and without cognitive impairment or dementia, pure vascular dementia (VaD) or AD is uncommon. Indeed, most patients with VaD or AD also have other types of pathology, the most common of which is a combination of AD (characterised by the diffuse accumulation of amyloid‐β plaques and neurofibrillary tangles composed of tau) and cerebrovascular disease (CeVD). Method Several different VCI criteria have been proposed. The more recent VASCOG, DSM‐5 and the VICCCS criteria may have greater sensitivity, modest concurrent validity and better predictive validity than older criteria such as the NINDS‐AIREN and DSM‐4 criteria for VaD. Importantly, diagnoses for vascular MCI can now be made using the newer criteria which may be useful for clinical and research purposes which include establishing cognitive trajectories, prognostic biomarkers and better understanding of the underlying mechanisms. Result As vascular imaging biomarkers of small vessel disease of the brain are established, well characterized, and easy to recognize, it has been suggested that these vascular biomarkers should be incorporated into the AD Research “ATN” Framework for a biological definition of AD. This presentation will discuss ways in which the AD and VCI criteria can be bridged. Conclusion Whether this effort to bridge AD and VCI is achieved by integration or combination, it would enable a better understanding of both AD and VCI pathophysiology and aid in treatment efforts which is currently mainly through prevention by treating vascular diseases and other risk factors, such as hypertension and diabetes mellitus, until the much anticipated advent of disease‐modifying treatments.