AbstractBackgroundWhen studying the causes of dementia, there are certain difficulties in differentiating existing cerebrovascular changes. We present the features of cerebrovascular changes in Alzheimer’s disease (AD) and in distal forms of cerebral atherosclerosis.MethodsThe research included 935 patients, of whom: 93 people aged 34‐80 (mean age 67.5), 32 men (34.40%), 61 women (65.59%), suffered from AD. According to their dementia severity, the patients were subdivided: (TDR‐0) ‐ 10, (TDR‐1) ‐ 29, (TDR‐2) ‐ 36, (TDR‐3) ‐ 18;• 842 people aged 29‐81 (mean age 74.5), 622 men (73.87%), 220 women (26.13%), with distal cerebral atherosclerosis and chronic cerebrovascular insufficiency. According to their dementia severity, the patients were subdivided: (CDR‐1) ‐ 284, (CDR‐2) ‐ 18.• The examination plan included cerebral MRI, CT, scitrigraphy (SG), rheoencephalography (REG), cerebral multi‐gated angiography (MUGA).ResultsIn patients with AD, changes in angioarchitectonics and microcirculation are manifested in:• Absence of calcium salts deposits and atherosclerotic changes in intracerebral arteries;• Increased tortuosity of the distal parts of the intracerebral arteries;• Reduction of the capillary bed in the temporal and frontoparietal regions;• Development of multiple large arteriovenous shunts with early venous discharge of arterialblood in the same regions;• Development of abnormal venous trunks in the same regions;• Development of intracerebral stagnation of venous blood;These changes are called “Dyscirculatory angiopathy of Alzheimer’s type” (DAAT).In patients with distal cerebral atherosclerosis, changes in angioarchitectonics and microcirculation are manifested in:• Multiple calcium salts deposition and atherosclerotic changes in the intracerebral arteries;• Multiple disseminated contraction of the intracerebral capillary bed;• Development of multiple small disseminated intracerebral arteriovenous shunts;• Lack of pronounced intracerebral venous congestion.ConclusionsDyscirculatory angiopathy of Alzheimer’s type (DAAT), regardless of the severity of dementia, is an AD‐specific cerebrovascular and microcirculatory lesion of the brain not associated with atherosclerotic processes.In patients with distal cerebral atherosclerosis, regardless of the severity of dementia, vascular disorders are of disseminated atherosclerotic character. Anatomically, the lesion of the capillary bed and the presence of arteriovenous shunts are of disseminated character, and there is no pronounced venous stasis. Timely detection of these changes is very important for diagnosis.