Recent epidemiological and clinico-pathological data indicate considerable overlap between cerebrovascular
disease (CVD) and Alzheimer’s disease (AD) and suggest additive or synergistic effects of both pathologies on
cognitive decline. The most frequent vascular pathologies in the aging brain and in AD are cerebral amyloid
angiopathy and small vessel disease. Up to 84% of aged subjects show morphological substrates of CVD in addition
to AD pathology. AD brains with minor CVD, similar to pure vascular dementia, show subcortical vascular lesions in
about two-thirds, while in mixed type dementia (AD plus vascular dementia), multiple larger infarcts are more
frequent. Small infarcts in patients with full-blown AD have no impact on cognitive decline but are overwhelmed
by the severity of Alzheimer pathology, while in early stages of AD, cerebrovascular lesions may influence and
promote cognitive impairment, lowering the threshold for clinically overt dementia. Further studies are warranted
to elucidate the many hitherto unanswered questions regarding the overlap between CVD and AD as well as the
impact of both CVD and AD pathologies on the development and progression of dementia.
Keywords: Alzheimer’s disease, Cerebrovascular lesions, Cerebral amyloid angiopathy, Cognitive impairment,
Lacunes, Microinfarcts, Small vessel disease, White matter lesions