First Aid/Stroke & TIA
A stroke is an acute loss of or impairment to brain functionality caused by local insufficient circulation in the affected brain region. This leads to oxygen starvation to that part of the brain and, if prolonged, in consequence brain cells die.
A fair understanding of the condition will aid your learning. Technically, a stroke is pretty similar to the previously discussed heart attack and angina, sometimes a stroke is even called a brain attack, yet the brain is an even more delicate and complex structure.
There are two causes, both of which occurring in a blood vessel of the brain:
- An ischaemic stroke is caused by a small blockage of a blood vessel of the brain. The blockage is usually caused by a small blood clot, although incursions such as air bubbles can have the same effect.
- A hemorrhagic stroke occurs in the case of a rupture of a blood vessel. The walls of bloods vessels may be thinner at some point and especially in combination with high blood pressure, this may be the site of a rupture.
The actual cause is irrelevant to us, but will determine clinical care and long-term treatment.
Furthermore, we distinguish between a
- CVA, cerebro-vascular accident (sometimes also just called a stroke or major stroke) and a
- TIA, transient ischaemic attack (sometimes called mini stroke).
Historically, both were defined simply by the duration of the symptoms. If the symptoms passed in the 24 hours past onset, the condition was called a TIA, otherwise a CVA. Today, the differentiation is based on time and detectable tissue damage, but the details are still up for debate.
|There is no hemorrhagic equivalent to a TIA.|
Obviously, for the purposes of first aid, a stroke must be treated in the same way regardless of its classification. Waiting for hours for symptoms to pass in order to tell a CVA and TIA apart would not meet the purposes of first aid, nor do we have the diagnostic tools (such as fMRI) available.
|To test for the affected side of a stroke, have the victim squeeze your hands at the same time. You will notice a difference in pressure that they may not.|
The deficit of oxygen can cause an acute loss of functions related to the area of the brain affected. An asymptomatic stroke is termed silent stroke, yet still involves tissue loss.
The key recognition signs for a stroke can be remembered with the acronym FAST. It stands for and is assessed by the the following indication:
- Facial weakness?
- Can the person smile correctly? Observe if one side of the face droops.
- Arm weakness?
- Can the person raise both arms and hold them parallel without one drifting? If they squeeze your hands can they exert equal force?
- Speech problems?
- Can the person articulate clearly and repeat a simple sentence correctly?
- Call the local EMS phone number or take the patient to the hospital immediately. If witnessed, record the time of onset of symptoms.
The victim may also experience additional symptoms, which on their own typically do not indicate a stroke. These include:
- sudden blurred, dim or patchy vision
- sudden dizziness
- sudden, severe, unusual headache
A great deal of the brain is (predominantly) organized contralaterally. This means processing stimuli from and controlling movement for the left half of the body happens in right side of the brain, and vice versa.
If the patient’s left facial muscles are not stimulated to the full extent (drooping smile), if the patient is not able to exert about the same force with their left hand, we can infer a deficit in the right part of the brain.
- Every second counts. Call for an ambulance.
- Reassure the victim.
- Encourage and facilitate the victim to move in to a position of comfort if possible.
If they have significant paralysis, they may be unable to move themselves, so you should make them as comfortable as possible where they are. If possible, incline them to the, with regard to visible/external symptoms, unaffected side (if there is one), as this will help you relieve some symptoms such as a feeling of floating.
- Take vitals, history and regular observations
- may lose consciousness after you have established a suspected stroke, or
- an eyewitness accompanying the victim reports a sudden lateralized deficit in their walking abilities, which eventually caused them to fall to a particular side, and lose consciousness.
In theses cases, treat first what kills first:
- Assess the victim’s ABCs (attempt CPR if not breathing).
- Additionally, assist the victim into the recovery position on their (with regard to visible/external symptoms) unaffected side. Due to the contralateral organization of the forebrain as explained above, we have reason to think the stroke occurred on the respective side. In this position gravity may assist blood to reach the injured side of the brain, which is then below the unaffected side of the brain. Moreover, bleeding (if any) may drain out the auditory canal.
When reassuring the victim, have a realistic picture of the condition in mind. Unfortunately, most patients will have significant impairments afterwards. A FAST response is key to mitigate effects, yet some causes of stroke are particularly fatal.
The human brain is quite flexible. The function of brain cells that have died may be taken over by nearby living brain cells, but this requires a long process of learning, rehabilitation, and will never have same quality as the original cells, since these were highly-specialized and optimized for their task. This ability of the brain, called neuroplasticity, however, decreases with advanced age.
A stroke may also be the turning point of a patient’s habits. They will be put on a treatment plan, for example in order to manage excessive blood pressure, thus reducing their general risks. However, refrain from making accusations: “You have been smoking too much (tobacco).” or similar will not be appreciated.