Vascular dementia (VaD) is the second most common form of dementia after Alzheimer's disease (AD). It's caused by damage to brain tissue, which occurs because of decreased blood flow. Blood flow to brain tissue may be completely blocked by a clot in a blood vessel, or blood flow may be decreased but not completely blocked by a partial blockage in blood vessels in the brain.
VaD may develop gradually, or it may become apparent after a stroke or after undergoing major surgery, such as heart bypass surgery or abdominal surgery.
Facts about VaD
Dementia and other related diseases and conditions are difficult to distinguish because they share similar signs and symptoms. Although VaD is caused by problems with blood flow to the brain, this blood flow problem can happen in different ways. So, different types of VaD are based on how each type occurs:
Mixed dementia. In some cases, symptoms of both VaD and AD exist. When mixed dementia occurs, however, it is generally considered to be a form of dementia with some characteristics of AD, rather than a case of AD with characteristics of VaD.
Multi-infarct dementia. This occurs after several small, often "silent," blockages repeatedly affect blood flow to a certain area of the brain. The changes that occur after each blockage may not be apparent, but over time, the combined effect begins to cause symptoms of impairment. Multi-infarct dementia is also called vascular cognitive impairment.
Men, especially those younger than 75, are affected by VaD more often than women.
Researchers think that VaD will become more common in the next few decades because:
VaD is generally caused by conditions that occur most often in older people, such as atherosclerosis (hardening of the arteries), heart disease, and stroke.
The number of people older than 65 years is increasing.
People are living longer with chronic diseases, such as heart disease and diabetes.
Causes of VaD
VaD is caused by a lack of blood flow to the brain. Blood flow to a certain part of the brain may be decreased or interrupted by:
Bleeding because of a ruptured blood vessel
Damage to a blood vessel from atherosclerosis, infection, or other causes, such as an autoimmune disorder
The effect of decreased or no blood flow depends on the size and location of the area affected. If a very small area in a part of the brain that controls memory is affected, for example, you may experience "forgetfulness" that doesn't necessarily change your ability to carry on normal activities. If a larger area is affected, you may have difficulty thinking clearly or solving problems, or greater memory problems that do change your ability to function normally.
CADASIL (cerebral autosomal dominant arteriopathy with sub-cortical infarcts and leukoencephalopathy) is a genetic disorder that generally leads to dementia of the vascular type. One parent with the gene for CADASIL passes it on to a child, which makes it an autosomal-dominant inheritance disorder. It affects the blood vessels in the white matter of the brain. Symptoms, such as migraine headaches, seizures, and severe depression, generally begin when a person is in his or her mid-30s; however, symptoms may not appear until later in life.
Risk factors for VaD
Risk factors for vascular dementia include risk factors for the conditions associated with VaD, such as heart disease, stroke, diabetes, and atherosclerosis:
High blood pressure
High cholesterol and triglyceride levels
Atrial fibrillation (fast and irregular rate of the upper two heart chambers)
High level of homocysteine in the blood, which can cause damage to blood vessels, heart disease, and blood clots
Lack of physical activity
Overweight or obesity
Oral contraceptive use
Conditions that cause the blood to "thicken" or clot more easily
Family history of dementia
Family history of CADASIL
Signs and symptoms of VaD
The symptoms of VaD depend on the location and amount of brain tissue involved. VaD symptoms may appear suddenly after a stroke, or gradually over time. Symptoms may get worse after another stroke, a heart attack, or major surgery. These are signs and symptoms of VaD:
Increased difficulty in carrying out normal daily activities because of problems with concentration, communication, or inability to carry out instructions
Memory problems, although short-term memory may not be affected
Confusion, which may increase at night (known as "sundown syndrome")
Stroke symptoms, such as sudden weakness and difficulty with speech
Mood changes, such as depression or irritability
Stride changes when walking too fast, shuffling steps
Problems with movement and/or balance
Urinary problems, such as urgency or incontinence
In addition to a complete medical history and physical examination, your doctor may order some of the following:
Computed tomography scan
Magnetic resonance imaging
Neuropsychological assessments. These tests can help distinguish VaD from other types of dementia and AD.
Psychiatric evaluation. This may be done to rule out a psychiatric condition that may resemble dementia.
VaD cannot be cured. The primary goal for VaD is to treat the underlying conditions that affect the blood flow to the brain. Treating these underlying conditions can help to reduce the risk factors for further damage to brain tissue.
Such treatments may include:
Medications to manage blood pressure, cholesterol, triglycerides, diabetes, and problems with blood clotting
Lifestyle modifications, such as following a healthy diet, getting physical activity, quitting smoking, and quitting or decreasing alcohol consumption
Procedures to improve blood flow to the brain, such as carotid endarterectomy, angioplasty, and/or stenting; the carotid arteries are located in the neck and provide blood flow from the heart to the brain
Medications, such as cholinesterase inhibitors to treat the progression of dementia
Long-term prognosis for VaD
VaD is a progressive disease that has no cure. A person with VaD will eventually need a high level of care as a result of the loss of mental abilities, as well as a decline in physical abilities. Family members may be able to care for a VaD patient early on. As the disease progresses, however, the person may need more specialized care.
Respite programs, adult daycare programs, and other resources can help the caregiver get some time away from the demands of caring for a loved one with VaD.
Long-term care facilities that specialize in the care of patients with dementias, AD, and other related conditions are often available once a person affected by VaD can no longer be cared for at home. Your doctor or other health care provider can provide caregiver resources.