Cerebrovascular Diseases

A cerebrovascular accident (CVA) or stroke is a neurologic symptom produced by cerebral ischemia and hemorrhage. The key clinical characteristics of cerebrovascular diseases are rapid or subacute onset and localized neurologic impairment. In addition, the impairment can be constant, progressing, or fully resolved based on the evaluation and the underlying cause. Apart from these shared characteristics, cerebrovascular diseases are a collection of disorders that are further categorized according to the location, cause, and symptoms.

Cerebrovascular diseases are classified into ischemic strokes and cerebral hemorrhages, each of which has a variety of origins or causes. Ischemic episodes are further categorized based on the location of symptoms in the carotid and vertebrobasilar arteries and the duration of symptoms. 

Transient ischaemic attacks (TIAs) are short-lived, lasting from a few minutes to a few hours at most. However, the neurologic impairment in ischemic stroke has been present for more than 24 hours and may be stable, progressive, or resolving.

What Causes Cerebrovascular Diseases 

The heart sends blood to the brain via two different sets of arteries known as the carotid and vertebral arteries. The carotid arteries are felt when you take your pulse right beneath your jaw. When you reach your neck’s highest point, the carotid arteries divide into external and internal arteries. The exterior provides blood to your face and the internal flowing deep into your skull. The internal carotid arteries branch within the brain into two major arteries, which are the middle cerebral and anterior arteries. It also divides into numerous smaller arteries: the ophthalmic, posterior communicating, and anterior choroidal arteries. These arteries provide blood to two-thirds of the brain.

The vertebral arteries run parallel to the spinal column and are completely invisible from the outside. The vertebral arteries merge to create a single basilar artery towards the skull base, near the brain stem. Numerous tiny branches from the vertebrobasilar system enter the brain stem and branch off to create the posterior cerebellar and posterior meningeal arteries, which feed the brain’s rear third. The jugular vein and many additional veins drain blood from the brain.

Since the brain receives blood from just two sets of large arteries, these arteries must remain healthy. Often, the root cause of an ischemic stroke is a blockage of the carotid arteries by a fatty deposit known as plaque. A hemorrhagic stroke occurs when an artery in or near the brain ruptures or leaks. It results in bleeding in or around the brain.

Regardless of the underlying cause, normal blood flow and oxygenation to the brain must be restored quickly. Without oxygen and other nutrients, the afflicted brain cells will start to incur damage and die. Once brain cells production decreases, they cannot recover, and severe damage may ensue, leading to cognitive, physical, and mental impairments.

Types of cerebrovascular diseases and treatment

Ischemic Stroke

The most frequent form of stroke, responsible for the majority of cases, is an ischemic stroke. It is classified into two types: thrombotic and embolic. The former happens when a blockage, referred to as a thrombus, obstructs an artery leading to the brain, cutting off blood flow. On the other hand, an embolic stroke develops when a fragment of plaque or thrombus travels downstream and obstructs an artery. An embolus is a term used to describe the substance that has migrated. How far downstream the blockage occurs in the artery determines the extent to which the brain is impacted.

In most instances, the carotid or vertebral arteries remain partially blocked, allowing a tiny stream of blood to reach the brain. Reduced blood supply to the brain depletes the cells of nutrients, which rapidly results in cell dysfunction. A stroke occurs when a portion of the brain ceases to function. A core region is cut off from blood during a stroke, and the cells start exhibiting deterioration within 5 minutes. Nevertheless, there is a much wider region around the center of dead cells called the ischemia penumbra. The ischemia penumbra is made up of cells that are damaged and unable to function yet remain alive. These cells are referred to as idling cells, and they may remain dormant for about three hours.

Ischemic stroke is addressed by eliminating the blockage and reestablishing normal blood to the brain. One FDA-approved therapy option for ischemic stroke is a tissue plasminogen activator (tPA). It works best when given within a three-hour window after the start of symptoms. Regrettably, only around 3% to 5% of stroke victims reach the nearby hospital to be evaluated for this therapy. Furthermore, this drug increases the risk of cerebral bleeding and is thus not recommended for hemorrhagic stroke.

Hemorrhagic Stroke

Hemorrhagic strokes may be caused by aneurysm, hypertension, or a vascular malformation, or as a side effect of anticoagulant therapy. Intracerebral hemorrhage happens when blood enters the brain tissue directly, forming a clot inside the brain. When bleeding covers the cerebrospinal fluid regions around the brain, it is referred to as subarachnoid hemorrhage. Both of these diseases are very severe.

Hemorrhagic strokes are often treated surgically to alleviate intracranial stress created by bleeding. In addition, surgical treatment of hemorrhagic stroke induced by an aneurysm or a faulty blood artery may help avoid further strokes. First, an MRI scan is used to assess the damage, and then surgery is conducted to close the defective artery and reroute flow to other arteries supplying blood to the same area of the brain.

Endovascular therapy entails introducing a long, thin, flexible tube (catheter) into a major artery, often in the thigh, directing it to the aneurysm and putting small stents into the blood vessel through the catheter. Stents provide support for the blood vessel, preventing further damage and strokes.

Rehabilitation and recovery are critical components of stroke therapy. In certain instances, regions of the brain that have not been injured may carry out tasks that were lost after the stroke. Speech therapy, physical therapy, and occupational therapy are all types of rehabilitation.

Regardless of the kind of stroke, victims must get emergency medical care and medical imaging as quickly as possible to ensure the best possible result. In addition, by being familiar with the stroke signs and symptoms and addressing risk factors, it is feasible to help avoid the disease’s severe consequences.

Transient Ischemic Attack (TIA)

A transient ischemic attack (TIA) is a kind of cerebrovascular disease that causes no lasting harm. For example, a temporary blockage of a cerebral artery often results in stroke-like indications, but the blockage is resolved before lasting damage happens.

Although the symptoms of a TIA are similar to those of a stroke, they disappear rapidly. In addition, symptoms would be so imprecise and transient that individuals “brush” them aside, particularly if they persist for a few minutes.

While there is no therapy for the TIA, it is critical to identify and address the cause of the TIA before another incident occurs. If you develop TIA symptoms, get emergency medical treatment and inform your primary care physician. The sooner you seek medical care, the more quickly a diagnosis can be made and therapy started. Early intervention is critical for preventing a massive stroke successfully. Treatment options for individuals who have had a TIA are limited to carotid artery disease or cardiac issues.

Cerebrovascular Disease Diagnostic Tests

Diagnostic imaging scans can identify most cerebrovascular diseases. In addition, neurosurgeons can examine the arteries and veins in or around the brain and the brain tissue itself using these tests.

Cerebral Angiography  

Since arteries are not usually visible on an X-ray, contrast dye is used. A local anesthetic is administered, the artery is perforated, often in the leg, and a syringe is introduced into the artery. A catheter is introduced into the artery through the needle. It is then run via the abdominal and chest major vessels until it reaches the neck arteries. A fluoroscope is used to monitor this operation. After injecting the contrast dye into the neck region through the catheter, X-ray images are obtained.

Carotid Duplex

Ultrasound can aid in detecting blood clots, plaque, or other obstructions to blood circulation in the carotid arteries. First, a water-soluble gel is applied to the skin area where the transducer is to be implanted—the gel aids in transmitting sound to the skin’s surface. Then, the ultrasound machine is activated, and pictures of the carotid arteries and pulse waveforms are acquired. There are no recognized dangers, and this test is completely painless and noninvasive.

Computed Tomography (CT)

A diagnostic picture is produced when a computer reads x-rays. In certain instances, a drug will be injected into a vein to aid in the visualization of brain regions. The density of bone, blood, and brain tissue is very different and readily differentiated on a CT scan. Because blood may readily be seen on a CT scan, it is an excellent diagnostic tool for hemorrhagic strokes. However, the damage caused by an ischemic stroke may not be seen for many hours or days on a CT scan. CTA (Computed Tomography Angiography) enables physicians to see blood arteries in the neck and head and is increasingly utilized in place of an invasive angiogram.

Electroencephalogram (EEG)

A diagnosis in which electrodes are put on the scalp of a subject to detect electrical signals. These electrical impulses are written as brain waves.

Lumbar Puncture (spinal tap)

An invasive procedure involves extracting cerebrospinal fluid from the area around the spinal cord using a needle. This test may aid in the detection of bleeding produced by a brain hemorrhage.

Magnetic resonance imaging (MRI)

 An MRI imaging creates a comprehensive image of your brain by using strong radio waves and magnets. For example, an MRI Elizabeth NJ may identify brain tissue that has been affected by an ischemic stroke or hemorrhages in the brain. In addition, your doctor may inject a dye into a blood vessel to enable visualization of the arteries and veins and demonstrate blood flow.