Friday, 15 November 2013

Vascular dementia

What is vascular dementia?
Vascular dementia is a general term describing problems with reasoning, planning, judgement, memory and other thinking skills that are significant enough to interfere with daily social or occupational functioning, and are caused by brain damage that has resulted from impaired blood flow in the brain.
Vascular dementia can sometimes develop after a stroke blocks an artery in the brain, but strokes don’t always cause vascular dementia. Whether a stroke affects thinking and reasoning depends on the severity and location of the stroke. Vascular dementia more often results from many small strokes or other conditions that damage blood vessels and reduce circulation, reducing the supply of vital oxygen and nutrients to brain cells.
In Alzheimer’s disease, memory problems, especially forgetting recent events, is often the most prominent symptom. In vascular dementia however, executive functions (planning, reasoning, judgement), spatial processing and attention are often more impaired.
Pure vascular dementia is not common. Often, vascular damage occurs alongside Alzheimer’s disease or other brain disease and exacerbates the dementia, rather than being the primary cause.

What causes vascular dementia?

There are many different forms of vascular disease affecting the brain. Each of these result in restricted blood flow to the brain which damages brain cells. The location and size of this brain damage determines which brain functions are affected. Vascular dementia may be diagnosed when there is evidence of vascular brain damage and symptoms of dementia, and the evidence suggests a link between the vascular disease and the dementia

Vascular dementia is the second most common type of dementia. People with vascular dementia often have a series of small strokes. These are so small that they are generally not aware of them. The strokes can interrupt the blood supply to the brain, resulting in damage that causes dementia. The gaps between the strokes can be weeks, months or longer. This type of vascular dementia is called multi-infarct dementia.
Vascular dementia can also be caused by:
  • high blood pressure (hypertension)
  • irregular heart rhythms (arrhythmias)
  • diseases which damage the arteries in the brain
About 20 per cent of people with dementia have vascular dementia. Another 20 per cent have vascular dementia and Alzheimer’s disease at the same time.
Like Alzheimer’s disease, vascular dementia often affects the person’s memory and their ability to recognise things and people. If it is caused by strokes, the person’s symptoms can get worse suddenly. Afterwards they may improve slightly or remain stable until they have another stroke.