Causes and symptoms of vascular dementia

Risk factors for stroke are also risk factors for vascular dementia. They include hypertension, diabetes, atrial fibrillation, smoking, coronary heart disease, heart failure, carotid murmur, alcohol abuse, old age, and male gender. Additional risk factors for vascular dementia include low educational level, unskilled labor, the presence of the APOE-e4 allele, the absence of estrogen replacement therapy during menopause, the presence of epileptic seizures, abnormal heart rhythms, and pneumonia. The presence of these factors supports the diagnosis of vascular dementia, but is not mandatory for its establishment. Nevertheless, measures aimed at reducing these risk factors are one of the most important areas in the prevention and treatment of vascular dementia.

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Risk factors for vascular dementia

• Arterial hypertension
• Diabetes mellitus
• Smoking
• Coronary heart disease risk
• Heart rhythm disturbances,
• Heart failure
• Noise over the carotid arteries
• Old age
• Male gender
• Low educational level
• Profession
• APOE-e4
• Epileptic seizures
• Uncorrected estrogenic deficiency

It is customary to distinguish several subtypes of vascular dementia.

Thus, in a recently published review by Coppo, eight of them were identified. The first subtype of vascular dementia is multi-infarct dementia. It is characterized by the presence of multiple large cerebral infarcts, often resulting from cardiogenic embolism. According to some data, 27% of cases of vascular dementia belong to this type. The second type of vascular dementia is associated with single or multiple infarcts localized in strategic areas (thalamus, white matter of the frontal lobe, basal ganglia, angular gyrus). This subtype accounts for 14% of cases of vascular dementia.

The third subtype of vascular dementia is characterized by the presence of multiple subcortical lacunar infarcts that arise due to arteriosclerotic or degenerative changes in the walls of deep penetrating arterioles, often associated with arterial hypertension or diabetes mellitus. Clinically, in this case, the development of dementia may be preceded by episodes of transient ischemic attacks or strokes with good functional recovery, but often the brain damage remains subclinical for a certain time, and subsequently manifests itself as a gradually increasing cognitive defect, imitating the symptoms of Alzheimer's disease. Neuroimaging reveals subcortical lacunar infarcts. Lacunar infarcts lead to the development of disconnection syndromes with a decrease in blood flow and metabolic activity in remote cortical and subcortical structures. This is the most common subtype of vascular dementia, accounting for approximately 30% of its cases.

Subtypes of vascular dementia

• Multi-infarct dementia
• Single infarction or multiple infarctions localized in “strategic” zones
• Multiple subcortical lacunar infarcts
• Arteriosclerotic subcortical leukoencephalopathy
• A combination of large and small infarcts affecting cortical and subcortical structures
• Hemorrhagic foci, infarction dementia.
• Subcortical lacunar infarctions due to genetically determined arteriolopathies
• Mixed (vascular and Alzheimer's) dementia

The fourth subtype of vascular dementia is Binswanger's disease, or arteriosclerotic subcortical leukoencephalopathy. Pathologically, Binswanger's disease is characterized by a decrease in the density of the white matter, resulting from a partial loss of myelin sheaths, oligodendrocytes, and axons. Small vessels supplying the white matter are occluded by fibrohyaline tissue. Clinically, the disease manifests itself as dementia, limb rigidity, abulia, and urinary incontinence. Differential diagnosis must be made with AIDS, multiple sclerosis, or the effects of radiation. Binswanger's disease progresses gradually or in stages, and neurological symptoms increase over several years. Neuroimaging reveals multiple lacunar infarctions, periventricular white matter changes, and hydrocephalus.

The fifth subtype of vascular dementia is characterized by a combination of large and small infarcts involving both cortical and subcortical structures.

The sixth subtype of vascular dementia occurs as a result of hemorrhagic brain damage in intracranial hemorrhages. Risk factors in this case are uncontrolled arterial hypertension, arteriovenous malformations, intracranial aneurysms.

The seventh subtype of vascular dementia is caused by genetically determined arteriopathy, which causes subcortical lacunar infarctions. Pathologically, in this case, damage to small penetrating arteries supplying blood to the basal ganglia and subcortical white matter is revealed. Examples include familial amyloid angiopathy, coagulopathy or cerebral autosomal dominant arteriopathy with subcortical infarctions and leukoencephalopathy - CADASIL.

The eighth subtype of vascular dementia is a combination of vascular dementia and Alzheimer's disease (mixed dementia). These are usually patients with a family history of Alzheimer's disease, who also have risk factors for stroke. Neuroimaging reveals cortical atrophy and cerebral infarctions or hemorrhagic foci. This subtype of vascular dementia also includes patients with Alzheimer's disease who have developed intracerebral hemorrhage as a complication of concomitant amyloid angiopathy.