The brain has a rich network of blood vessels, ranging from the large arteries to the tiny vessels deep in the brain. The term ‘Chronic Small Vessel Disease’ (CSVD) refers to the physical changes caused by small vessel disease including thickening of the vessel walls, disturbance of the blood-brain barrier, and demyelination of the nerve sheaths.
How Chronic Small Vessel Disease develops is unclear, although there are two main pathological features. These are lesions of the subcortical, deep and periventricular white matter, generally referred to as white matter lesions (WML) and lacunes (lacunar infarcts) of the central grey matter, including the thalamus and basal ganglia.
Chronic Small Vessel Disease is relatively common in the elderly, and is considered a natural consequence of ageing. It is rare younger patients.
Chronic Small Vessel Disease is the second most common causes of dementia, after Alzheimer’s disease, and significantly increases the likelihood of the patient suffering a major stroke. The various studies I have read put that risk anywhere from twice to nine times normal. It’s hard to find consensus.
Symptoms of Chronic Small Vessel Disease of the Brain
Symptoms range in severity. Some people have no symptoms at all, while others have marked impairment and obvious deficits. Severity of symptoms is related to the degree of damage done to the vessels and which area(s) of the brain are affected.
Common symptoms include:
Trouble speaking or understanding speech
Vision loss, or blurred vision
Depression or mood changes
Urinary problems (urinary retention and incontinence)
What Causes Chronic Small Vessel Disease of the Brain
In the edlerly, the damage to the brain is most likely caused by multiple tiny bleeds in the brain. This is a natural consequence of ageing, and some extent of small vessel disease of the brain is common in by the time a person reaches 80 years old.
Small vessel disease is much rarer in younger people, however. In younger people it is most often caused by a disease process or high blood pressure. High blood pressure weakens and damages the tiny vessels in the brain. These vessels ultimately break and cause micro-bleeds and multiple tiny strokes. People with Chronic Small Vessel Disease are at a far higher risk of experiencing a major haemorrhagic stroke. Lacunar strokes, usually small strokes caused by a blockage of the small arteries that supply the brain’s deep structures, are also common. The extent of symptoms and deficits depend on the location and size of the strokes.
Diabetes is also a risk factor. High blood glucose levels can damage blood vessels and increase the risk of atherosclerosis (hardening of the arteries).
Cerebral white matter disease, cerebral micro-bleeds and lacunar infarcts (stroke caused by a clot) and intracerebral haemorrhages (stroke caused by a bleed) are small vessel disease related lesions. Lacunar infarcts and white matter lesions are commonly seen on MRI in people with CSVD.
When small vessel disease is present in the brain, it is likely present in other small vessels in the body, such as the eyes, and the heart. When the small arteries in the heart are damaged, it may cause signs and symptoms of heart disease, including chest pain. Because the narrowing of these arteries makes it harder for the heart to pump blood, small vessel disease in the heart can lead to congenital heart failure or heart attack.
Treatment of Small Vessel Disease of the Brain
There is no treatment for Chronic Small Vessel Disease. The focus is to reduce risk factors and preventing further damage. These include reducing blood pressure, blood cholesterol and keep blood sugar levels in the normal range. This can be achieved with lifestyle changes, such as following a healthy diet and exercising. If lifestyle changes aren’t enough, medications to lower blood pressure and cholesterol are considered. Blood sugar levels also need to be well controlled.