Vascular dementia
Vascular dementia is dementia caused by a series of strokes.[2][4] Restricted blood flow due to strokes reduces oxygen and glucose delivery to the brain, causing cell injury and neurological deficits in the affected region.[6] Subtypes of vascular dementia include subcortical vascular dementia, multi-infarct dementia, stroke-related dementia, and mixed dementia.[2][5]
Vascular dementia
Cognitive impairment, short term memory loss[3]
Heart disease, loss of ability to care for self,loss of ability to interact, pneumonia[4]
Conditions that impair blood vessels in the brain and therefore interfere with oxygen delivery to the brain[3]
High blood pressure, high cholesterol, atrial fibrillation, diabetes[3]
Lab test, neuroimaging test, neuropsychological testing[5]
Alzheimer disease[5]
Subcortical vascular dementia occurs from damage to small blood vessels in the brain. Multi-infarct dementia results from a series of small strokes affecting several brain regions. Stroke-related dementia involving successive small strokes causes a more gradual decline in cognition.[4] Dementia may occur when neurodegenerative and cerebrovascular pathologies are mixed, as in susceptible elderly people (75 years and older).[2][5] Cognitive decline can be traced back to occurrence of successive strokes.[4]
ICD-11 lists vascular dementia as dementia due to cerebrovascular disease.[1] DSM-5 lists vascular dementia as either major or mild vascular neurocognitive disorder.[7]
Signs and symptoms[edit]
People with vascular dementia present with progressive cognitive impairment, acutely or sub-acutely as in mild cognitive impairment, frequently step-wise, after multiple strokes.[5]
The disease is described as both a mental and behavioral disorder within the ICD-11.[8] Signs and symptoms are cognitive, motor, behavioral, and for a significant proportion of people, also affective. These changes typically occur over a period of 5–10 years. Signs are typically the same as in other dementias, but mainly include cognitive decline and memory impairment of sufficient severity as to interfere with activities of daily living, sometimes with presence of focal neurological signs, and evidence of features consistent with cerebrovascular disease on brain imaging (CT or MRI).[4][5]
The neurological signs localizing to certain areas of the brain that can be observed are hemiparesis, bradykinesia, hyperreflexia, extensor plantar reflexes, ataxia, pseudobulbar palsy, as well as gait problems and swallowing difficulties. People have patchy deficits in terms of cognitive testing. They tend to have better free recall and fewer recall intrusions when compared with people having Alzheimer's disease.[9] In the more severely affected people, or those affected by infarcts in Wernicke's or Broca's areas, specific problems with speaking called dysarthria and aphasias may be present.[2][5]
In small vessel disease, the frontal lobes are often affected. Consequently, people with vascular dementia tend to perform worse than their Alzheimer's disease counterparts in frontal lobe tasks, such as verbal fluency, and may present with frontal lobe problems: apathy, abulia (lack of will or initiative), problems with attention, orientation, and urinary incontinence. They tend to exhibit more perseverative behavior. People with vascular dementia may also present with general slowing of processing ability, difficulty shifting sets, and impairment in abstract thinking. Apathy early in the disease is more suggestive of vascular dementia.[2][5]
Rare genetic disorders that cause vascular lesions in the brain have other presentation patterns. As a rule, they tend to occur earlier in life and have a more aggressive course. In addition, infectious disorders, such as syphilis, can cause arterial damage, strokes, and bacterial inflammation of the brain.[10]
Prevention[edit]
Early detection and accurate diagnosis are important, as vascular dementia is at least partially preventable. Ischemic changes in the brain are irreversible, but the person with vascular dementia can demonstrate periods of stability or even mild improvement.[18] Since stroke is an essential part of vascular dementia,[13] the goal is to prevent new strokes. This is attempted through reduction of stroke risk factors, such as high blood pressure, high blood lipid levels, atrial fibrillation, or diabetes mellitus.[2][5]
Medications for high blood pressure are used to prevent pre-stroke dementia.[19] These medications include angiotensin converting enzyme inhibitors, diuretics, calcium channel blockers, sympathetic nerve inhibitors, angiotensin II receptor antagonists or adrenergic antagonists.
A 2023 review found that therapy with statin drugs was ineffective in treating or preventing stroke or dementia in people without a history of cerebrovascular disease.[20]
Prognosis[edit]
Many studies have been conducted to determine average survival of people with dementia. The studies were frequently small and limited, which caused contradictory results in the connection of mortality to the type of dementia and the person's gender. One 2015 study found that the one-year mortality was three to four times higher in people after their first referral to a day clinic for dementia, when compared to the general population.[21] If the person was hospitalized for dementia, the mortality was even higher than in people hospitalized for cardiovascular disease.[21] Vascular dementia was found to have either comparable or worse survival rates when compared to Alzheimer's disease;[22] another 2014 study found that the prognosis for people with vascular dementia was worse for male and older people.[23]
Vascular dementia may be a direct cause of death due to the possibility of a fatal interruption in the brain's blood supply.[24]
Epidemiology[edit]
Vascular dementia is the second-most-common form of dementia after Alzheimer's disease in older adults.[4] The prevalence of the illness is 1.5% in Western countries and approximately 2.2% in Japan. It accounts for 50% of all dementias in Japan, 20% to 40% in Europe and 15% in Latin America. 25% of people with stroke develop new-onset dementia within one year of their stroke. One study found that in the United States, the prevalence of vascular dementia in all people over the age of 71 is 2.43%, and another found that the prevalence of the dementias doubles with every 5.1 years of age.
The incidence peaks between the fourth and the seventh decades of life and 80% of people have a history of hypertension.[25]
A 2018 meta-analysis identified 36 studies of prevalent stroke (1.9 million participants) and 12 studies of incident stroke (1.3 million participants).[13] For prevalent stroke, the pooled hazard ratio for all-cause dementia was 1.69; for incident stroke, the pooled risk ratio was 2.18.[13] Study characteristics did not modify these associations, with the exception of sex, which explained 50.2% of between-study heterogeneity for prevalent stroke. These results confirm that stroke is a strong, independent, and potentially modifiable risk factor for all-cause dementia.[13]