<s>[INST] context: Alzheimer's disease Coical atrophy Deposition of amyloid b plaque & tangles Cerebellar amyloid angiopathy Association with chromosome 14 and chr.1 Premature Alzheimer's - mutation in App gene (amyloid precursor protein)-on chr.21 3 copies of chr.21 -more amyloid precursor protein?premature Alzheimer's Downs syndrome patients have high risk of Alzheimer's disease Abnormal folding of Ab peptides causes aggregation within neurons and apoptosis Some degenerative diseases of the CNS are associated with neuronal intracytoplasmic inclusions, such as neurofibrillary tangles of Alzheimer disease and Lewy bodies of Parkinson disease Cerebral amyloid angiopathy (CAA) is the risk factor most commonly associated with lobar hemorrhages. In CAA, amyloidogenic peptides, usually the same ones found in Alzheimer disease are deposited in the walls of medium and small caliber meningeal and coical vessels. This deposition can weaken the vessel wall and lead to hemorrhage. Many individuals with CAA have evidence of numerous small hemorrhages within the brain ("microbleeds"), which can be visualized by various imaging methods. As with Alzheimer disease, in which there is a relationship between a polymorphism in the gene that encodes apolipoprotein E (ApoE) and risk of disease,there is an effect of the ApoE genotype on the risk of recurrence of hemorrhage from sporadic CAA. The presence of either an e2 or e4 allele increases the risk of repeat bleeding. While some mutations in the precursor protein for the Ab peptide (amyloid precursor protein, APP) cause familial Alzheimer disease, others result in autosomal dominant forms of CAA. [/INST] question: Which of the pathognomic feature of Alzheimer's disease? | options: A: Lewy body B: Plaques and tangles C: Pick bodies D: Red neuronal degeneration | answer: B </s>