What is vascular dementia?

A common form of dementia is vascular dementia. The incidence of vascular dementia is rising steadily.

Many people are unaware that they are at risk of developing vascular dementia and in some cases it can be largely prevented.

In this article:

• What causes vascular dementia?
  
• Different types of vascular dementia
  
• Vascular dementia signs and symptoms
  
• Vascular dementia risk factors
  
• Vascular dementia diagnosis
  
• Vascular dementia treatment & management
  
• Vascular dementia prevention

What causes vascular dementia?

Vascular dementia is a form of dementia caused by problems associated with poor circulation of blood to the brain. Our vascular system supplies the brain with blood and oxygen via a network of blood vessels.

If our vascular system becomes damaged, brain cells do not receive adequate amounts of blood and the brain will not function properly.

A number of conditions can cause or lead to damage of the vascular system. These conditions include high blood pressure, high cholesterol, diabetes, stroke and heart problems. 

Different types of vascular dementia

Multi-infarct dementia

Multi-infarct dementia is a common form of vascular dementia. This occurs when a series of small strokes disrupt the blood supply to the brain and damage brain tissue.

A small stroke is often referred to as a transient ischaemic attack (TIA). A TIA causes symptoms similar to stroke including weakness or paralysis of the face or limb, slurred speech, dizziness and confusion.

Symptoms of a TIA generally last no more than 20 minutes when a person’s condition appears to improve. However, the effects of these small strokes become more apparent over time when a person has problems with learning, memory and language. 

Subcortical vascular dementia 

Subcortical vascular dementia or Binswanger's disease is caused by damage to tiny blood vessels deep within the brain. It is caused by high blood pressure, poor blood flow and thickened arteries.

Symptoms can appear more gradually and can include:

• Difficulty walking
• Mood swings
• Loss of bladder control
• Slowness in thinking and actions
• Lethargy

Unlike Alzheimer's disease people with multi-infarct dementia usually have greater insight into their condition. Personality traits may also stay intact for longer. 

Stroke

Vascular dementia can also be caused by a single large stroke. A stroke occurs when there is an interruption in the flow of blood to the brain. A stroke can be caused by a blockage in the vessels to the brain or when a blood vessel bursts.

Symptoms of stroke depend on the area of the brain that is damaged. Dementia can be caused by one single stroke but not everyone who has a stroke will develop dementia.

Sudden onset of confusion, loss of memory, speech or motor changes can be a sign of a stroke in the brain. Seek medical help immediately by calling 000 if a person shows signs of a stroke or TIA. 

Mixed dementia 

Mixed dementia, a combination of Alzheimer's disease and vascular dementia is becoming more common in people as they age. It is thought that vascular dementia can increase the progression of Alzheimer's disease. 

Vascular dementia signs and symptoms

Vascular dementia affects everyone differently. Symptoms will depend on the area of the brain that is damaged. Progression of the condition will also vary.

Symptoms of vascular dementia usually occur in a stepwise manner where a person appears to stabilise or get better until they have another stroke and their condition deteriorates suddenly.

A person can also have a series of small strokes that are less obvious and difficult to detect. Symptoms may not be apparent until after several strokes.

Sign and symptoms of vascular dementia may include:

• Weakness or paralysis in an arm or leg
• Slurred speech
• Difficulty concentrating and communicating
• Periods of acute confusion
• Epilepsy
• Depression
• Hallucinations
• Incontinence 

Vascular dementia risk factors

Many of the risk factors for vascular dementia can be managed. Risk factors for vascular dementia include:

• Increasing age
• Untreated high blood pressure
• Irregular heart rhythms
• Diabetes
• High cholesterol
• Family history of stroke or vascular dementia
• Smoking
• Unhealthy lifestyle including a diet high in saturated fats, excessive alcohol and lack of physical activity
• Male 

Vascular dementia diagnosis

Early diagnosis of vascular dementia is vital. As vascular dementia can co-exist with Alzheimer's disease it can be difficult to diagnose.

The first person to see is a doctor. A doctor will want to know about a person's symptoms and medical history. A person may be referred to a specialist for cognitive tests. These simple tests look at memory, thinking and calculating. Diagnosing dementia may also involve a brain scan. 

Vascular dementia treatment & management

Brain damage caused by vascular dementia cannot be reversed. Treatment of vascular dementia focuses on preventing further strokes and keeping existing medical problems such as heart disease and diabetes under control.

A doctor may prescribe medication to prevent further clots from forming or to treat depression or sleep disturbance. As people with vascular dementia may have pre-existing heart disease, many people often die of a heart attack or major stroke.

In rare cases surgery to relieve a blockage in the carotid artery, the main blood vessel to the brain, may be performed. 

Vascular dementia prevention

A person can reduce the risk of further strokes by following a healthy diet, engaging in physical activity, avoiding smoking and taking any medication as prescribed. 

Helpful resources

• For more information about dementia visit Alzheimer's Australia or call the National Dementia Helpline on 1800 100 500. 

References

Alzheimer's Society UK,
What is vascular dementia?
Accessed 01/0708 

Alzheimer's Australia 
Vascular dementia
Accessed 01/07/08

Alzheimer's Association America
Vascular dementia
Accessed 01/07/08