How to Recognize the Signs and Symptoms of a Stroke
Learning how to recognize when someone is having a stroke can minimize the damage it can cause. In this article, we'll discuss the signs of a stroke, what to do when you identify these signs, risk factors, and how a stroke can affect your brain.
Time is the single most important factor to consider when a stroke is identified.
Think FAST to Recognize a Stroke
FAST is an easy way to remember the earliest symptoms indicating the onset of a stroke.
F: Facial asymmetry. Has one side of the mouth dropped/deviated?
A: Arms. Does one arm seem to drift down?
S: Speech. Are the words slurred?
T: Time. Call emergency services as soon as possible.
The full list of symptoms include weakness or numbness of the face, arms, or legs (on one or both sides), difficulty speaking, confusion, loss of balance, vision defects, difficulty swallowing, and headaches.
Why is it so important to act quickly?
When a blood vessel that supplies oxygen to an area of the brain is blocked (stroke), the region will begin to die off, but the surrounding regions will remain viable for a few hours (4-5 hours). If that critical period is passed, this viable region will also die, causing further disability. Therefore, it is vital to identify the symptoms early and seek medical assistance as soon as possible.
What Should You Do When You Identify a Stroke?
- Call 911 and make sure that the surrounding environment is safe.
- Note the time that symptoms first appear. This is important for the treatment plan because a medicine called rtPA (recombinant tissue plasminogen activator) has to be given within 4.5 hours in order to dissolve the clot that is causing trouble.
- Keep the person in the recovery position.
- Check their breathing to make sure their airway isn't obstructed. See if the chest is moving and if you can feel their breath. Put your ear close to their nose and mouth to listen for breathing
- If there are no signs of breathing, start CPR (cardiopulmonary resuscitation) only if you are certified.
- Check the patient's responsiveness by asking him/her to squeeze your hand. If the person is unresponsive, they are likely unconscious.
- Check for any secretions from the mouth (saliva, vomit, blood, etc.) and wipe off if necessary.
- Loosen tight clothing and keep the person warm.
- Support their head with a cloth or pillow.
- Keep them calm until help arrives.
DO NOT put any food, drinks, or medication in the patient's mouth because their ability to swallow may be compromised.
It is always better to call emergency services instead of driving the patient yourself because they'll be able to reach the hospital faster. Emergency personnel can also bring them to a hospital that specializes in stroke management and perform life-saving techniques on the way.
Stroke Risk Factors
Many comorbidities and behaviours can contribute to increased risk of stroke:
- High blood pressure
- Excess alcohol consumption
- High cholesterol
- Atrial fibrillation (a rhythm disturbance in the upper heart chambers)
- Severe carotid stenosis (narrowing of the carotid artery which supplies the brain)
- Sedentary life style
- Sleep apnea.
It is very important to keep these conditions under control to reduce risk. It has been found that there is a 67% reduction in the risk of stroke if atrial fibrillation is controlled, a 33% reduction if smoking is stopped, and a 28% reduction if high blood pressure is controlled.
However, there are some risk factors that you can't control for, such as genetics, age, and ethnicity. Individuals above the age of 60 are at greater risk. Stroke rates are higher in African Americans and Asians populations than Caucasian populations.
How Does a Transient Ischemic Attack Affect Your Risk of Getting a Stroke?
A transient ischemic attack (TIA) is a brief episode of neurological dysfunction caused by focal brain ischemia without infarction.
Infarction vs Ischemia
Ischemia is the loss of blood supply to a particular organ or tissue, but there is no death if blood flow is re-established. Infarction occurs when there is prolonged lack of blood to an organ or tissue which ultimately causes it's death. Therefore, prolonged ischemia can cause infarction.
During a TIA, There is no permanent disability like in the case of a stroke. The symptoms of a TIA can include speech defects, paralysis of limbs, visual defects, balance problems, dizziness, and difficulty swallowing.
Studies have shown that 30% of people can have a stroke in the first five years after a TIA, In certain cases, a stroke can occur in the first two days following a TIA. The ABCD2 score can help assess the risk of a subsequent stroke.
The ABCD2 Score for Risk of a Stroke After TIA
Age: 60 or older
Blood pressure: Greater than 140/90
Clinical: Unilateral weakness
Clinical: Speech impairment
Duration: 60 minutes or more
Duration: Less than 60 minutes
A score of less than four poses minimal risk, while a score greater than six indicates a high risk for a stroke within 7 days after a TIA.
Prevention is always best. Strokes are highly preventable if the known risk factors are controlled. Awareness about the common symptoms can also minimize disability to yourself and your loved ones.
How Does a Stroke Affect Brain Function?
Our brain is the most metabolically active organ in the body, consuming around 15-20% of the total blood pumped by the heart. It is also very susceptible to damage if the cerebral blood flow is dysfunctional.
A stroke occurs when the blood supply to a section of the brain is lost or reduced. This can either be due to an infarction (the obstruction of a blood vessel causing local death of the tissue) or a hemorrhage. Whatever the cause may be, it results in the lack of oxygen to the affected brain area causing death. When areas of the brain are deprived of oxygen, they die, and the functions performed by those particular regions will be weakened.
An infarction occurs when there is insufficient blood flow to a particular area for a long time. It can be caused by to many factors, such as clots that can block blood vessels or diseases affecting the patency of the vessels. A hemorrhagic stroke occurs when there's a rupture of the blood vessels supplying the brain. It can also occur due to several structural malformations.
Kumar, P. J. & Clark, M. L. (2009). Kumar & Clark's clinical medicine (7th ed.). Edinburgh: Saunders/Elsevier.
Colledge, N. R., Walker, B. R., Ralston, S., & Davidson, S. (2010). Davidson's principles and practice of medicine. Edinburgh: Churchill Livingstone/Elsevier.