Definition and Overview
Vascular dementia is a type of dementia in which brain tissue is damaged due to cerebrovascular damage such as cerebral infarction, cerebral hemorrhage, and chronic cerebrovascular disease, leading to a decline in cognitive function. It is the second most common form of dementia after Alzheimer's disease, accounting for approximately 15-20% of all cases.
Recently, it is treated as a broad concept called vascular cognitive impairment, encompassing a continuum from mild cognitive decline to dementia. In elderly patients, a mixed type in which both Alzheimer's pathology and vascular pathology exist together is common. In ICD-10, it is classified into the F01 series and I67.9, which indicates cerebrovascular disease.
Causes and Pathophysiology
Vascular dementia is divided into several types depending on the size of damaged blood vessels and lesion pattern.
- Multiple infarction dementia: Cognitive function gradually deteriorates due to the accumulation of multiple large vessel cerebral infarctions.
- Strategic infarction dementia: Dementia can occur even if a single infarction occurs in areas key to cognition, such as the thalamus and hippocampus.
- Subcortical ischemic vascular dementia: The small blood vessels (small blood vessels) in the brain are chronically damaged, causing white matter degeneration and multiple lacunar infarcts to accumulate and progress slowly.
Subcortical damage caused by small vessel disease breaks the circuit connecting the frontal lobe and the subcortex, reducing executive function and processing speed. Among the risk factors, high blood pressure is the most important, followed by diabetes, dyslipidemia, smoking, atrial fibrillation, and old age.
symptoms
The clinical manifestations of vascular dementia vary depending on the area and extent of damage, but the following characteristics are common.
- Gradual deterioration: In many cases, the condition worsens suddenly or progresses in steps in line with the timing of the stroke.
- Predominant decline in executive function: Decrease in planning, judgment, and processing speed appears first and more clearly than memory.
- Focal neurological signs: Hemiplegia, paresthesia, dysarthria, gait disturbance, and dysphagia.
- Others: Depression, apathy, and difficulty controlling emotions (pathological crying and laughing) are common.
However, the form caused by small vessel disease progresses slowly without a clear stroke, so it may be difficult to distinguish it from Alzheimer's disease.
diagnosis
Diagnosis aims to confirm cognitive decline and demonstrate that the decline is temporally and anatomically related to cerebrovascular lesions.
- History taking: history of stroke, progressive deterioration pattern, vascular risk factors identified
- Neurological examination: check for local neurological signs such as hemiplegia and gait disturbance
- Neuropsychological testing: Assessment of cognitive domains including executive function and processing speed
- Brain MRI: Evaluation of location and burden of vascular lesions such as infarction, hemorrhage, white matter high-signal lesion, and lacunar
- Blood tests and cardiac evaluation: Check for vascular risk factors and embolic sources (such as atrial fibrillation)
Vascular dementia is diagnosed when vascular lesions are sufficient compared to the degree of cognitive decline and a correlation between the two is recognized.
treatment
Vascular risk factor management
The key to treating vascular dementia is preventing additional cerebrovascular damage. Control high blood pressure, diabetes, and dyslipidemia to target levels, and quit smoking, abstain from drinking, and exercise regularly. If atrial fibrillation is present, embolic cerebral infarction can be prevented with anticoagulant treatment, and recurrence can be reduced with antiplatelet medication when necessary.
Drugs and Rehabilitation Treatment
There is no established drug specifically for stopping vascular dementia itself. In the mixed type with Alzheimer's pathology, cholinesterase inhibitors or memantine are used to relieve cognitive symptoms. Motor, language, and cognitive rehabilitation after stroke contributes to recovery and maintenance of function.
Non-pharmacological management
Regular exercise, cognitive stimulation, social activity, and depression management help maintain cognitive function. Managing vascular risk factors is beneficial not only for cerebrovascular disease but also for preventing dementia overall.