Stroke/CVA is a type of cardiovascular disease. It affects the arteries leading to the brain as well as within the brain itself. A blood vessel in the brain becomes blocked by a clot or burst. That means that part of the brain does not get the blood flow or the oxygen it needs, and starts to die. We often refer to these as bleeds.
Types of Strokes
There are three different types:
- Ischemic - refers to a clot of some type
- Hemorrhagic - Anteriovenous malforcation (AVM)
- Transient Ischemic attack (TIA)
Ischemic bleeds are caused by two different reasons. Cerebral thrombosis is a clot that forms in a location along the major arteries. Cerebral embolism is a clot that forms in another part of the body and it breaks off and travels to the brain.
Ischemic bleeds count for about 83% of all cases that result from an obstruction. These clots are also known as aneurysms, they are the ballooning of a weakened region of a blood vessel. If left untreated, it can rupture and bleed into the brain.
An AVM is a cluster of abnormally formed blood vessels. This can also rupture and cause bleeding into the brain. These Hemorrhagic strokes cause about 17% of stroke cases in the United States a year.
TIA’s are considered minor, but they are warning signs of a stroke. The obstruction occurs for a short time and resolves itself normally.
Aneurysms can form mostly after the age of 40; they develop at branching points in the arteries and are caused by the constant pressure of the blood flow. As they get larger they become weaker, and this happens slowly. They may also be associated with other types of blood vessel diseases like Fibromuscular dysplasis, cerebral arteritis or arterial dissection. These are very unusual however.
Aneurysms may run in families but you are not born with it. An infection, drugs like amphetamines and cocaine also cause damage to the brain blood vessles or a direct head trauma. They very in size, shape, and location and can occur in the front or the back of the head. To diagnosis an aneurysms a CAT scan (Computed Tomography) or MRI (Magnetic Resonance Imaging) with special dyes that enhance the arteries are used to see them better. Causes of an aneurysm to bleed can be high blood pressure, strong emotions, and blood thinners. If the aneurysm bleeds it can cause a sudden and severe headache that can last hours to days.
Nausea, vomiting, drowsiness and/or coma, weakness or paralysis of an arm or leg, trouble speaking or understanding, vision problems and seizures. When an aneurysm bleeds there is a 30-40% chance of moderate to severe brain damage even if treated. If the stroke is not treated quickly there is a chance that another bleed may occur from the already ruptured aneurysm. Treating an aneurysm after it bleeds will not reverse the damages, but it will help prevent more bleeding and causing more damage.
When an AVM occurs it is described as a tangle of blood vessels in the brain. It bypasses normal brain tissue and directly diverts blood from the arties to the veins. AVM are more common in men but occurs in less than 1% of the population. It is usually congenital (born with it) but it is not hereditary. Causes of an AVM are because the vessels are weakened directing blood flow away from the normal brain tissue.
The vessels dilate and eventually burst from high pressure in the blood flow from the arteries causing bleeding into the brain. Symptoms are possible seizures, localized pain in the head due to the increase blood flow around AVM. Some people may have problems with speech, movement and vision. An AVM bleed can affect one or more normal body functions depending on where it is in the brain.
- Frontal lobe-personality
- Parietal-the movement of arms and legs
- Temporal-speech, memory, and understanding
- Cerebellum-walking and coordination
- Ventricles-secretion of cerebrospinal fluid
- Brain stem-pathways from all the above function to the rest of the body
Transient Ischemic Attacks
TIA symptoms may disappear but they are strong indicators of a possible major stroke that may happen if steps are not taken immediately to prevent it.
Treatments for strokes depend on the size, location, and shape as well as the overall medical condition of the patient. In the acute (sudden onset) setting a clot buster called tissue plasmingen activator (tPA) needs to be given within three hours of the onset of symptoms. This can reduce long-term disability for the most common type of stroke, Ischemic.
Medical therapy is what everyone should do. It starts with annual check ups, monitor blood pressure, cholesterol, and other medical conditions. You can always get the surgeons involved depending on the risk factors surgery can be performed. Clips are placed around the base of the aneurysm so blood cannot enter. There are also techniques that are used when a catheter is places through the blood vessel and into the aneurysm itself.
The surgeons place soft platinum micro coils which seal off the blood flow to the clot. There are also anticoagulants/antiplatletes like Aspirin or warfarin. You could have a carotid endarterectomy where the blood vessel blockage is surgically removed. Finally there is an angioplasty/stents where they implant a steel screen to take care of the fatty buildup that clogs up the vessel so it cannot adhere to it.
The most important thing to remember is the signs of stroke. Stroke is a medical emergency and needs to be dealt with as soon as possible, even if the signs go away. If any of these happen, call 911:
- Numbness or weakness of face, arms or legs especially on one side.
- Confusion, talking or understanding
- Trouble seeing in one or both eyes
- Trouble walking, dizziness, loss of balance or coordination
- Severe headache with no known cause
Ask the individual three simple questions that will help you recognize a stroke
1) Ask a person to smile. If one corner of the mouth is drooping, call 911.
2) Ask a person to raise both arms in front of you. If one hand drifts down, call 911.
3) Speak a simple sentence and ask a person to repeat it. If he or she has trouble repeating the sentence, call 911.