What is a Stroke?
One term that is becoming common in describing stroke is “brain attack.” Just as a heart attack is caused by disrupted blood flow to tissue in the heart, a stroke consists of disrupted blood flow to the brain. When oxygen rich blood is unable to reach tissue, the result is cell death. Another term you may hear is “CVA,” which stands for cerebral vascular accident. Seven hundred and fifty thousand Americans suffer from strokes each year. Of this number, 160,000 will die. There are currently about four million stroke survivors in the United States today.
The warning signs and symptoms of a stroke or mini stroke (transient ischemic attack or TIA) can include:
- Sudden weakness, numbness or paralysis of the face, arm or leg (especially on one side)
- Loss of speech or trouble talking or understanding language
- Sudden loss of vision (especially in one eye)
- Sudden severe headache with no apparent cause
- Unexplained dizziness, loss of balance or coordination (especially with the above symptoms)
- Partial or total loss of consciousness
- Vomiting or severe nausea (when other symptoms are present)
It is ideal to get treatment immediately after the symptoms begin. If symptoms last greater than 10-15 minutes, appear frequently or seem to get worse, call 911. When a stroke occurs, time is extremely valuable. Every minute you waste could be the minute that saves your brain!
To learn more about how to identify a stroke, click here to watch the FAST animated video.
The Effects of Stroke on the Brain
It’s important to remember that no two brains are alike. Stroke causes cell death or damage to the brain. Because no two brains are alike, no two strokes are alike. However, research has found that there are similarities in how each of the different parts of our brains function. By knowing the location of damage to the brain, your treatment team may be more prepared to assist you in your recovery process.
Right-Brain Injury: The right side of the brain controls motor function on the left side of the body. Therefore, difficulty with movement is typically seen on the left side of the body. The right side of the brain also controls emotions, thinking skills, nonverbal communication and spatial orientation (sense of body position). Attention, memory and judgment for safety could be affected as well.
Left-Brain Injury: The left side of the brain controls motor function on the right side of the body. Difficulty with movement is typically seen on the right side of the body. Language is controlled by the left side of the brain. Therefore, there may be language problems present. Mood and behavior may be affected as well.
Basic Brain Functions
Frontal lobe: Initiation of activities, problem-solving, judgment, inhibition of behavior, planning movements of the body, personality/emotions, awareness of abilities/limitations, organization, concentration, expressive language
Temporal lobe: Memory, hearing, understanding language, organization and sequencing
Parietal lobe: Sense of touch, differentiation of size/shape/color, spatial awareness, ability to perceive visual information
Occipital lobe: Vision
Cerebellum: Balance, coordination, skilled movement activities
Brain Stem: Breathing, heart rate, consciousness/arousal, sleep/wake functions, attention/concentration
Major Types of Stroke
Ischemic: An ischemic stroke occurs when there is a blockage in a blood vessel. This causes tissue death, or what is also called a cerebral infarct. Eighty-five percent of all strokes are ischemic. When the blood clot is still and narrows the artery, it is termed thrombotic. When a piece of blood clot breaks off and travels in the blood stream until it becomes stuck, it is termed embolic.
Hemorrhagic: A hemorrhagic stroke occurs when there is bleeding in or around the brain. Fifteen percent of all strokes are hemorrhagic. However, 30 percent of all stroke deaths are hemorrhagic. In this type of stroke, the blood vessel may rupture and cause limited blood flow in or around the brain. A clot can also form and move brain tissue disrupting brain function. If there is a subarachnoid hemorrhage, this means that the bleeding is occurring in the space between the brain and the skull. If there is an intracerebral hemorrhage, this means that the bleeding is within the brain tissue itself.
TIA: You may have also heard the term “TIA.” This stands for a transient ischemic attack, sometimes called a “mini-stroke.” During a TIA, there are temporary interruptions in the blood supply to the brain. This causes temporary stroke symptoms. A TIA can last anywhere from a few minutes to several hours, but less than 24 hours. Statistics show that one third of all persons who have experienced a TIA will have a stroke at some time. There is also high risk for stroke survivors to have another stroke at some point in their lives.