WHAT IS A STROKE?
A stroke or
brain attack occurs when a blood clot blocks a
blood vessel or artery, or when a blood vessel breaks, interrupting blood
flow to an area of the brain. When a brain attack occurs, it kills brain
cells in the immediate area. Doctors call this area of dead cells
an infarct. These cells usually die within
minutes to a few hours after the stroke starts.
When brain
cells in the infarct die, they release chemicals that set off a chain
reaction called the "ischemic cascade." This chain reaction endangers brain
cells in a larger, surrounding area of brain tissue for which the blood
supply is compromised but not completely cut off. Without prompt medical
treatment this larger area of brain cells, called the penumbra, will also
die. Given the rapid pace of the ischemic cascade, the "window of
opportunity" for interventional treatment is about six hours. Beyond this
window, reestablishment of blood flow and administration of
neuroprotective agents may fail to help and can
potentially cause further damage.
When brain cells die, control of abilities which that
area of the brain once controlled are lost. This includes functions
such as speech, movement, and memory. The specific abilities lost or
affected depend on where in the brain the stroke occurs and on the size of
the stroke (i.e., the extent of brain cell death). For example, someone who
has a small stroke may experience only minor effects such as weakness of an
arm or leg. On the other hand, someone who has a larger stroke may be left
paralyzed on one side or lose his/her ability to express and process
language. Some people recover completely from less serious strokes, while
other individuals lose their lives to very severe strokes.
Brain
Attack Means Medical Emergency
Educating the public to treat stroke as a brain attack and to seek emergency
treatment is crucial because every minute lost, from the onset of symptoms
to the time of emergency contact, cuts into the limited window of
opportunity for intervention. The majority of patients don't report to the
emergency room until more than 24 hours after the onset of stroke symptoms.
The longer the delay in patient presentation, the more damage a stroke can
do and the less recovery can be achieved.
One of the largest obstacles to emergency treatment is that many people
don't even know it when they are having a stroke. The University of
Cincinnati reported that 52 percent of their acute stroke patients were
unaware they were experiencing a stroke. Another factor in time of
presentation is where people are when they have strokes. Those who have a
brain attack in a public place where others may recognize the symptoms or
see that something is wrong tend to report to the emergency room sooner.
That is why it is critical for everyone to "Be Stroke Smart" and
learn the 3 Rs of
stroke: Reduce risk, Recognize symptoms, Respond by calling 911.