Cerebrovascular Disease

The word cerebrovascular is made up of two parts – “cerebro” which refers to the large part of the brain, and “vascular” which means arteries and veins. Together, the word cerebrovascular refers to blood flow in the brain. The term cerebrovascular disease includes all disorders in which an area of the brain is temporarily or permanently affected by ischemia or bleeding and one or more of the cerebral blood vessels are involved in the pathological process. Cerebrovascular disease includes stroke, carotid stenosis, vertebral stenosis and intracranial stenosis, aneurysms, and vascular malformations.

Restrictions in blood flow may occur from vessel narrowing (stenosis), clot formation (thrombosis), blockage (embolism) or blood vessel rupture (hemorrhage). Lack of sufficient blood flow (ischemia) affects brain tissue and may cause a 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)
– Confusion
– Difficulty communicating, including slurred speech
– Loss of half of vision
– Loss of balance
– Loss of consciousness

CAUSES
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).

TYPES
Some common forms of cerebrovascular disease are stroke, transient ischemic attack (TIA), sometimes called a mini-stroke, and subarachnoid hemorrhage. [aneurysm can result from a deformity in a blood vessel]

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.

TREATMENT
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.