Binswanger's disease

Causes and risk factors

Atherosclerosis, a disease process that narrows the blood vessels and cuts off the blood supply to the neurons or nerve cells of the brain, causing death of those cells, is a common cause of dementia.

Binswanger's disease is a particular type of atherosclerosis-related dementia, in which there are widespread, microscopic areas of damage to the white matter below the outer layer or cortex of the brain. This is called subcortical dementia and produces a particular pattern of symptoms which is somewhat different to other types of dementia.

The disease may develop gradually or seem to be triggered or rapidly aggravated by a stroke or other event that leads to brain damage.

Symptoms of Binswanger’s usually appear between about 55 and 65. Factors which increase the risk of atherosclerosis, such as smoking or a raised cholesterol level, may increase the risk of Binswanger’s.

As with other forms of dementia it can be difficult to be certain exactly what is causing the decline in brain function and patients may have a combination of arterial disease and damage related to conditions such as Alzheimer’s.

Symptoms

Binswanger's disease affects the speed at which the brain can process information and this typically causes problems with higher brain functions such as:

• Organisation
• Planning
• Decision making
• Attention
• Concentration (all of which impinge on intellectual function)
• Mood (typically apathy, irritability, and depression)
• Behaviour

Memory loss can occur but is not usually as bad as in other forms of dementia such as Alzheimer’s, while a feature known as psychomotor slowness (where a person takes longer than normal to turn a thought into an action) is common in Binswanger’s disease.

There may also be changes in speech, an unsteady gait, shaking similar to that seen in Parkinson's disease, clumsiness or frequent falls and loss of bladder control. These symptoms are not always present in all patients and may sometimes appear only as a passing phase. Seizures may also occur.

Patients usually show other signs of atherosclerosis and cardiovascular disease such as:

• Raised blood pressure
• Stroke
• Blood abnormalities
• Disease of the large blood vessels in the neck
• Disease of the heart valves

Brain scans such as CT scans or magnetic resonance imaging (MRI) show a characteristic pattern in Binswanger’s disease.

Treatment and prevention

There is no specific treatment for Binswanger's disease. What treatment there is consists of keeping associated symptoms under control and supporting the patient with their activities of daily living such as dressing, washing and preparing meals.

Medications may be used to treat symptoms such as depression, or generally treat arterial disease and its effects throughout the body (so helping to preserve blood flow to the brain and delay the progression of Binswanger’s).

Specific drugs called “cognitive enhancers” used generally in dementia may be given but the results with them are variable and many people get little benefit.

There is no cure for Binswanger's disease, and patients with the disorder usually die within five years of its onset.