By Intern: Armond Schwartz
It is common to hear people talk about strokes, but what exactly is a stroke? Simply put, a stroke is when a blood vessel going to the brain is blocked, or busts. This causes the brain to be damaged either by lack of oxygen or from having blood where it does not belong. Luckily, only the parts of the brain directly affected are damaged. Unfortunately, sometimes these parts can be critical. The type and extent of the damage dictates its severity.
There are two main types of strokes: hemorrhagic, and ischemic. There is also a third type of “mini-stroke” called a transient ischemic attack (TIA). Being familiar with the symptoms and risk factors for stroke can result in early treatment, and prevention. These interventions can prevent a stroke altogether, or minimize the damage. Stroke is the 5th leading cause of death in America and up to 80% of strokes are preventable.
Hemorrhagic strokes are the deadliest. They occur when the blood vessels that nourish the brain break or leak into the area on the outside or the brain, or directly into the brain. This type of stroke represents only 15% of all strokes, but is responsible for 40% of all stroke-related deaths. There are blood vessels within the brain as well as blood vessels located in between the brain and skull in a spot called the subarachnoid space. Because the skull creates a closed compartment, a bleed on the outside of the brain will put pressure on the brain and potentially cause damage. A bleed in the space on the outside of the brain is called a subarachnoid hemorrhage. A bleed directly inside of the brain is called an intracerebral hemorrhage. In the latter type of stroke, the free blood in the brain directly damages the brain matter.
What causes blood vessels to break? Sometimes blood vessels become weak, and bulge; this is called an aneurysm. These aneurysms can rupture and depending on the location, cause either a intracranial hemorrhage or subarachnoid hemorrhage. Additionally, some people have an improper structure to their blood vessels called an arteriovenous malformation (AVM) which has the potential of breaking, causing either subarachnoid or intracranial hemorrhages.
The other main type of stroke, called an ischemic stroke, is the result of a clog in the blood vessels supplying blood to the brain, thereby, depriving the brain of oxygen. The vessels carrying blood to the brain are called arteries. There are two types of ischemic stroke: embolic and thrombotic. Thrombotic strokes occur when a clot develops inside an artery supplying blood to the brain. Embolic stroke occurs when plaque or a clot from another part of the body enter an artery supplying the brain and blocks the blood flow. Ischemic strokes account for around 87% of all strokes.
The last type of stroke, called a transient ischemic attack (TIA) is like a “mini”-ischemic stroke. This type of insult will resolve on its own, generally within 24 hours. TIAs are not to be taken lightly though, 40% people who have TIAs will go on to develop a full blown stroke. In this way, TIAs can be seen as precursors to strokes. In fact, about 50% of all strokes occur in the days following a TIA.
All of this information sounds quite grim. But if caught early, some types of strokes are treatable. For this reason, it is important to know the signs and symptoms of a stroke. A sign is something an observer can see, but symptoms are things that can only be felt by someone having a stroke. Stroke signs and symptoms often come on suddenly, and they include: sudden numbness or weakness in the face, arm, or neck; confusion or difficulty understanding speech; sudden trouble seeing in one or both eyes; sudden onset of balance difficulty or dizziness; as well as sudden onset of an unexplainable headache. Depending on the part of the brain effected, signs/symptoms can be present on one or both sides of the body. This sounds like a lot to remember. Luckily, there is an acronym to help:
F: Face Drooping
A: Arm Weakness or numbness
S: Speech Difficulty
T: Time to Call 911
If you or anyone around you displays the first of these three signs/symptoms, call 911 immediately. With strokes, early treatment is critical to limiting their severity. It is important to write down when the signs/symptoms began. If treated within the first 3 hours, ischemic stroke patients can get a medication to break up clots and restore blood flow to the brain, thereby minimizing the damage caused by the stroke. Additionally, there are surgical procedures that can be utilized to achieve the same desired outcome.
Although these treatments can help minimize the damage of strokes, not having a stroke altogether is best. Wouldn’t you agree? That is why familiarizing yourself with the risk factors, and discussing stroke prevention strategies with your doctor is instrumental. Age is a common risk factor; for every decade of life after age 55, your stroke risk doubles. Having a family history of stroke is another risk factor, as is having a previous stroke, heart attack, or TIA. Females have a higher risk of stroke than do males. Additionally, women taking birth control medication or hormone replacement therapy have an elevated stroke risk. African Americans have a higher risk for stroke. Other risk factors include: diabetes, high blood pressure, high cholesterol, heart disease, peripheral artery disease, cigarette smoking, obesity, poor diet, sickle cell anemia, and sedentary lifestyle. If you have some of these risk factors it would be a good idea to talk with your healthcare provider about screening and preventive stroke measures. Anticoagulant and antihypertensive medications can help prevent a stroke. These measures, combined with discontinuing smoking, eating a healthy diet, and exercising regularly can help ensure a healthier lifestyle.
More information about strokes can be found at:
Longo DL, Fauci AS, Kasper DL, Hauser SL, Jameson J, Loscalzo J. Stroke. In:Longo DL, Fauci AS, Kasper DL, Hauser SL, Jameson J, Loscalzo J. eds. Harrison’s Manual of Medicine, 18e. New York, NY: McGraw-Hill; 2013.http://accessmedicine.mhmedical.com/content.aspx?bookid=1140&Sectionid=63497791. Accessed January 22, 2016.
Strokeassociation.org. Stroke Treatments. 2016. Available at: http://www.strokeassociation.org/STROKEORG/AboutStroke/Treatment/Stroke-Treatments_UCM_310892_Article.jsp#.Vq6kw_krKhc. Accessed January 19, 2016.
Strokeassociation.org. Learn More Stroke Warning Signs and Symptoms. 2016. Available at: http://www.strokeassociation.org/STROKEORG/WarningSigns/Learn-More-Stroke-Warning-Signs-and-Symptoms_UCM_451207_Article.jsp#.Vq6khPkrKhc. Accessed January 29, 2016.
Stroke.org. Signs and Symptoms of Stroke. 2014. Available at: http://www.stroke.org/understand-stroke/recognizing-stroke/signs-and-symptoms-stroke. Accessed January 18, 2016.
Stroke.org. Stroke facts. 2014. Available at: http://www.stroke.org/understand-stroke/what-stroke/stroke-facts. Accessed January 16, 2016.