If a blockage, malformation, or hemorrhage prevents the brain cells from getting enough oxygen, brain damage can result.
Other examples include a narrowing or blockage in the carotid, intracranial, or vertebral arteries, known as stenosis.
In the United States (U.S.), cerebrovascular disease is the fifth most common cause of death. In 2014, it caused 41.7 fatalities per 100,000 people, or 133,103 deaths in total.
Here are some key points about cerebrovascular disease. More detail is in the main article.
- Cerebrovascular disease refers to a group of conditions that affect blood supply to the brain
- Early symptoms of a cerebrovascular attack include weakness and difficulty communicating
- Symptoms of a cerebral hemorrhage include a sudden, severe headache
- A cerebrovascular event is a medical emergency, and 911 should be called immediately
Atherosclerosis causes blockages in the blood vessels and is a common cause of stroke.
The signs and symptoms of cerebrovascular disease or a cerebrovascular attack depend on where the blockage or damage occurs, and how much cerebral tissue is affected.
Different events may have different effects, but common signs and symptoms include:
- a severe and sudden headache
- paralysis of one side (hemiplegia)
- weakness on one side (hemiparesis)
- difficulty communicating, including slurred speech
- loss of half of vision
- loss of balance
- loss of consciousness
What is F.A.S.T.?
The American Stroke Association urges the public to know the F.A.S.T. acronym as an aid to recognizing the warning signs of stroke:
- Face drooping
- Arm weakness
- Speech difficulty
- Time to call 911
Cerebrovascular disease happens for a variety of reasons.
If damage to blood vessels in the brain leads to a cerebrovascular attack, there will be little or no blood supply to parts of the brain. No blood means no oxygen, and, without oxygen, the brain cells will start to die. Brain damage is irreversible. Emergency help is needed.
Atherosclerosis is one type of cerebrovascular disease. It occurs when high cholesterol levels, together with inflammation in the arteries of the brain, cause cholesterol to build up in the vessel as a thick, waxy plaque that can narrow or block blood flow in the arteries.
This plaque can limit, or completely obstruct, blood flow to the brain. In time, this can cause a cerebrovascular attack, such as a stroke or a transient ischemic attack (TIA).
An aneurysm, resulting from a deformity in a blood vessel, can lead to a cerebrovascular attack.
An ischemic stroke occurs when a blood vessel that supplies blood to the brain is blocked by a blood clot or plaque. A clot, or thrombus, may form in an artery that is already narrow. A stroke happens when the lack of blood supply results in the death of brain cells.
A hemorrhagic stroke occurs when a blood vessel in part of the brain becomes weak and bursts open, causing blood to leak into the brain. This puts pressure on the brain tissue, causing tissue damage. The hemorrhage can also cause a loss of blood supply to other parts of the brain.
An aneurysm or a subarachnoid hemorrhage can result from defects in the blood vessels of the brain. If a blood vessel ruptures, the flow of blood that follows can damage brain cells.
An embolism happens when a clot breaks off from elsewhere in the body and travels up to the brain to block a smaller artery. This may cause an embolic stroke. This is more common in people who have arrhythmias, such as atrial fibrillation.
A tear in the lining of the carotid artery can lead to ischemic stroke in people aged under 40 years. The tear lets blood flow between the layers of the carotid artery, narrowing the artery and reducing blood flow to the brain.
Stroke is the most common type of cerebrovascular event.
It is more likely among males aged over 65 years, and especially if they or a close relative have previously had a stroke.
Factors that increase the risk of stroke and other types of cerebrovascular disease include:
- hypertension, or blood pressure of 140/90 mm Hg or above
- poor diet, and lack of exercise
- high blood cholesterol of 240 milligrams per deciliter (mg/dL) or over
Some of these can be prevented by making healthful lifestyle choices.
The same factors increase the risk of a cerebral aneurysm, but this can also happen to younger people with a congenital defect, or following a head trauma.
Vascular malformation can occur in the brain during pregnancy.
Other risk factors include:
- Moyamoya disease, a progressive condition that can lead to a blockage of the carotid arteries and their major branches
- venous angiomas, which affect 1 in 50 people and rarely bleed or cause symptoms
- a vein of Galen malformation, an arterial disorder that develops during gestation
Certain drugs and medical conditions can make the blood more likely to clot and raise the risk of ischemic stroke.
Hormone replacement therapy (HRT) may increase the risk of an attack in a person who already has atherosclerosis or carotid artery disease.
In the case of an acute stroke, a medication called tissue plasminogen activator (tPA) may be given. This breaks up the blood clot.
Rapid assessment and treatment is crucial, because some medications for stroke must be given within a certain time from the onset of symptoms.
A brain hemorrhage must be evaluated by a neurosurgeon, who may carry out surgery to reduce the pressure caused by the bleed.
Carotid endarterectomy involves making an incision in the carotid artery, and removing the plaque. This allows the blood to flow again. The artery is repaired with sutures or a graft.
In carotid angioplasty and stenting, a balloon-tipped catheter is inserted into the artery. The balloon is inflated so that it presses against the plaque, squashing it flat and reopening the artery.
A slender, metal mesh tube, or stent, is fitted inside the carotid artery to improve blood flow in the arteries blocked by plaque. The stent helps by preventing the artery from collapsing or closing up after the procedure is complete.
Reducing the risk of stroke
Blood platelet inhibitors including Aspirin, Dipyridamole, Ticlopidine, and clopidogrel reduce the risk of stroke before it happens. These can help patients with a history or a high risk of stroke.
Statins are cholesterol-lowering medications that are given for cerebrovascular disease, to decrease the risk of ischemic stroke.
Any cerebrovascular event is a medical emergency and 911 must be contacted for evaluation and support.
A brain scan can show damage to blood vessels and reveal which areas of the brain are affected.
At the hospital, a physician will ask about the patient's medical history and look for specific neurological, motor, and sensory deficits, such as changes in vision or visual fields, abnormal reflexes, abnormal eye movements, muscle weakness, decreased sensation, and other changes.
A cerebral angiography, vertebral angiogram, or carotid angiogram may be used. Dye that is injected into the arteries can reveal any clots and show up their size and shape.
A CAT scan can help diagnose and detect hemorrhagic strokes, because it can distinguish between blood, bone, and brain tissue. However, it cannot always reveal damage from an ischemic stroke, especially in the early stages.
An MRI scan can detect strokes, including in the early stages.
An electrocardiogram (EKG or ECG) can detect cardiac arrhythmia, a risk factor for embolic strokes.
Ways to reduce the risk of cerebrovascular disease include:
- not smoking
- getting regular physical exercise
- eating a low-fat diet
- maintaining a healthy weight
- controlling blood pressure
- lowering blood cholesterol with diet and medications if necessary
Individuals with heart arrhythmia should ask their doctor if they should be taking a blood thinner to prevent strokes.
Stroke and other cerebrovascular events can be fatal, but with rapid medical attention, a full or partial recovery is possible. People with cerebrovascular disease should follow healthy lifestyle tips and their doctor's instructions to reduce the chance of an attack.
The outlook depends on the type of event, how severe it is, and how quickly it is treated.
A cerebrovascular disease can be fatal or it can lead to long-term disability, but some people will make a full recovery.