Vascular dementia looks like other types of dementia, but it has different causes. Because of this, it can possibly be prevented.
Types of Vascular Dementia
This occurs when parts of the brain become damaged after a major stroke. It usually occurs when blood supply to a part of the brain is suddenly cut off. It may also be a result of bleeding in the brain, called a haemorrhagic stroke. Depending on which part of the brain is affected, the person may experience problems with movement, coordination, speech and sight.
Subcortical vascular dementia
This is the result of the cumulative effect of a series of small, “silent” strokes, which cause progressive changes in small blood vessels deep in the brain. The sufferer usually does not notice these changes, but over time, these strokes can damage parts of the brain that are important for attention, memory and language.
Difference between vascular dementia and Alzheimer's
As its name suggests, it originates in the vascular system – the network of vessels carrying blood around the body. The brain, with its own rich network of blood vessels, is especially vulnerable.
According to Dr Ng,
vascular dementia is caused by a sudden or step-by-step reduction in blood flow to the brain after a major stroke or a series of minor “silent” strokes.
“Blood carries essential oxygen and nourishment to the brain, and without it, brain cells can get damaged or die,” said Dr Ng.
Its symptoms are quite similar to Alzheimer’s disease. There is memory loss, disorientation and problems with communication. Patients may become slower in thinking and processing, and experience personality changes, including depression and apathy. There may be other specific symptoms, but they differ, depending on the area of the brain affected.
“Symptoms get worse over time, progressing over several years, but varying in speed from person to person. There may be a sudden or gradual change after a stroke,” said Dr Ng.
Dementia, on the other hand, results from a gradual degeneration of the brain over time. It is characterised by memory loss, impaired judgement, disorientation and behavioural changes severe enough to cause loss of function that affect work, hobbies, shopping, cooking, dressing, eating, bathing and toileting. Although not a normal part of ageing, it is more likely to happen to the elderly.
Why vascular dementia is preventable
Dr Ng said that
vascular dementia can potentially be prevented with good control of the underlying causes such as blood pressure, diabetes and high cholesterol. “In exceptionally rare cases, vascular dementia can be caused by an inherited genetic disorder, but most cases are sporadic and due to these underlying chronic diseases,” she added.
People most at risk of strokes are those with high blood pressure (hypertension), and those over 60 years old who are overweight, smoke, drink excessively, and have heart conditions, high cholesterol or diabetes.
“Many cases of vascular dementia are caused by small, silent strokes for which high blood pressure is the biggest factor. It leads to the narrowing of blood vessels and raises the risk of a stroke.”
Other threats to blood vessel damage in the brain include smoking, high cholesterol, diabetes, obesity, a sedentary lifestyle and heart problems.
“Although these risk factors can have a genetic basis, managing high blood pressure and high cholesterol might help to lower the risk of vascular dementia,” said Dr Ng.
But control must start at an early age because the effect is cumulative.
Research suggests that regular exercise and a healthy diet, especially in midlife and beyond, might help to lower our risk. Controlling chronic ailments – for example, quitting smoking and engaging in regular cognitive stimulation – could delay the onset of dementia.
Treatment of vascular dementia - if prevention fails
If the primary care physician suspects dementia, patients may be referred to a specialist clinic, where they will be given physical and memory tests, and brain scans, which help the doctor identify cognitive problems and the likely cause.
“Brain scans such as CT (computerised tomography) or MRI (magnetic resonance imaging) are helpful in diagnosing vascular dementia because they allow doctors to look for changes in blood vessels common in this type of dementia. Scans also help doctors rule out other conditions that could cause similar symptoms,” said Dr Ng.
Above: An MRI brain scan of a patient with vascular dementia. All the white areas in the brain, including the two prominent parallel white areas, show abnormalities.
There is currently no specific treatment for vascular dementia, but doctors will address the underlying related conditions.
They could prescribe medication for diabetes, stroke, high blood pressure, high cholesterol, heart problems or the same medication used to enhance cognition in Alzheimer’s disease.
Dr Ng said some of the symptoms may be managed by physiotherapy, occupational therapy or speech therapy. Patients may also benefit from cognitive therapy (activities designed to stimulate thinking skills and engage people).
“They are often group-based and include games, with an emphasis on enjoyment. They help to provide consistent mental and physical stimulation to slow down or prevent cognitive decline.”