Vascular dementia is the second most common type of dementia in older adults, after Alzheimer’s disease.
It results from injuries to vessels that supply blood to the brain, often after a stroke or series of strokes.
The symptoms of vascular dementia can be similar to those of Alzheimer’s, and both conditions can occur at the same time (a condition called "mixed dementia").
- Also known as vascular cognitive impairment.
- Pure vascular dementia accounts for 12 per cent of cases in the community, while Alzheimer’s and vascular dementia would account for 38 per cent of cases.
- It’s caused by a wide range of blockages and/or bleeding in the brain severe enough to cause damage to brain cells, resulting from strokes, small vessel disease, or Cerebral Amyloid Angiopathy (CAA). This causes the death of brain cells and prevents the brain from functioning as it should.
- If stroke-related, it can be caused by multiple or single events and permanent or temporary blockages.
- Small vessel disease is caused by disease of the very small blood vessels that lie deep in the brain. The blood vessels become thick-walled, stiff and tortuous, reducing blood flow to the deeper part of the brain. This causes small infarcts near the base of the brain and damages the bundles of nerves that carry signals around the brain. Historically this has been referred to as white matter disease.
- Cerebral Amyloid Angiopathy is associated with amyloid deposition in the walls of the arteries in the brain. This leads to microbleeds and haemorrhages in the brain.
What are the symptoms of vascular dementia?
- Early symptoms include periods of confusion, severe depression, emotional changes, mild memory loss, language and visuospatial impairment. As it progresses, the person’s thinking process slows down and the person would have difficulty planning, organizing and executing step-wise tasks.
- The symptoms often appear suddenly, following a major stroke or leakage of blood in the brain; but can also appear gradually through a series of strokes. The symptoms follow a step-wise progression.
- In post-stroke cognitive impairment, physical symptoms may be present, based on the part of the brain affected and the severity of stroke. It may be associated with weakness, paralysis, impaired speech or vision. The symptoms improve or stabilize in six months.
- In small vessel disease, the symptoms are usually of gradual onset, and less variable with time. The usual symptoms are the insidious onset of cognitive slowing, slowing of the thinking process, the early loss of bladder control, mild one-sided weakness, difficulty walking, clumsiness, lack of facial expression, difficulty with word pronunciation etc.
- Vascular dementia is considered the most preventable type of dementia because it is so closely related to cardiovascular health.
What are the risk factors for vascular dementia?
- Risk factors for vascular dementia are the same as those of cardiovascular disease - smoking, high blood pressure, diabetes, high cholesterol, physical inactivity, high-carb high-fat diet and ethnic origin (Indian, Pakistani, Bangladeshi, Sri Lankan, and African-Caribbean).
- Risks of developing vascular dementia can be reduced by keeping blood pressure, blood sugar, cholesterol and body weight in the recommended range and following healthy lifestyle choices including regular exercise, avoidance of smoking and limiting alcohol intake.
Several genetic disorders are associated with the development of vascular cognitive impairment.
- Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy (CADASIL) is a rare, inherited disorder that affects the small blood vessels in the brain and leads to vascular dementia or vascular cognitive impairment and other symptoms. This condition is associated with cognitive impairment, migraine headaches and risk of stroke. It is caused by an inherited genetic mutation (in the NOTCH3 gene) affecting small blood vessels.
- Another hereditary vascular syndrome is CARASIL that stands for Cerebral Autosomal Recessive Arteriopathy with