Which of the following regarding small vessel disease (SVD), cerebral amyloid angiopathy(CAand Alzheimer's disease (AD) is not true?

Ans. c. SVD is related to AD (Ref: Harrison 19/e p2565, 2583, 2598, 2602, 18/e p3276, 3296, 3304-3309)Cerebral Amyloid Angiopathy (CAA) is associated with Alzheimer's disease (AD) but Small vessel disease (SVD) is not associated."In dementia, both small vessel disease (SVD) and large vessel disease are found. But Alzheimer disease is caused by involvement of large vessels, while subcortical dementia like progressive supranuclear palsy (PSP) involves small vessels."''The term "small vessel" is used for small penetrating branches that arise at acute angles from the large arteries of circle of Willis, stem of the middle cerebral artery and the basilar artery. These arteries penetrate at right angles to supply the deeper structures within the brain e.g. basal ganglia, internal capsule, thalamus, pons. These arteries are prone to thrombosis and are common causes of ischemic stroke."With normal aging, there is also an accumulation of amyloid in cerebral blood vessels, leading to a condition called cerebral amyloid angiopathy (without dementia), which predisposes older persons to lobarhemorrhage and brain micro- hemorrhages (Small vessel disease). AD patients appear to be at increased risk for amyloid angiopathy, and this may explain some of the observed association between AD and stroke.""Cerebral amyloid angiopathy (CAA), although usually asymptomatic, is an important cause of primary lobar intracerebral hemorrhage in the elderly. It can occur as a sporadic disorder, sometimes in association with AD, or as a certain familial syndrome. CAA is characterized by deposition of cognophilic material in small to medium-sized blood vessels of the brain and leptomeninges. In its most severe stages, the amyloid deposits cause breakdown of the blood vessel wall with resultant hemorrhage."