Stroke: A useful guide to everything you need to know about strokes
There are approximately thousands of people who suffer from headaches, migraines, neck pains, etc. but what happens when these symptoms become acuter and are followed by others such as vomiting, numbness, etc?. Stroke was the second most frequent cause of death worldwide in 2011, accounting for 6.2 million deaths. The risk of stroke increases exponentially from 30 years of age. This article will be a useful guide to what is a stroke, what signs and symptoms should you be looking for, how to prevent a stroke and more.
What is a stroke?
A stroke is a cerebrovascular disease caused by an alteration or interruption of blood flow to the brain. A stroke happens when the blood supply to part of your brain is interrupted or severely reduced, depriving brain tissue of oxygen and nutrients. This causes the cells to die within minutes, affecting cognitive abilities among others.
This disorder is caused by the rupture or clogging of an artery.
- Rupture means that a part of the brain is flooded with blood
- Clogging means that blood does not reach a part of the brain due to some type of blockage.
“A neurological deficit of cerebrovascular cause that persists beyond 24 hours or is interrupted by death within 24 hours”- World Health Organization
There are numerous synonyms that we use to describe a stroke, among which we can highlight: thrombosis, embolism, cerebral vascular accident, CVA, cerebral hemorrhage, ictus, etc.
Signs and symptoms of a stroke
As described in the beginning, stroke signs and symptoms usually start suddenly, from seconds to minutes. Symptoms are going to depend on the area of the brain affected, the more brain areas it has affected the more cognitive functions are likely to be compromised. In most cases, the symptoms affect only one side of the body (unilateral). Depending on the part of the brain affected, the defect in the brain is usually on the opposite side of the body. So if your right side is the one experiencing the symptoms chances are that the stroke is happening on the left side of the brain.
When it comes to early recognition the acronym FAST is used as a mnemonic to help detect and enhance responsiveness to stroke victim needs.
- Face. Ask the person to smile. Does one side of the face droop?
- Arms. Ask the person to raise both arms. Does one arm drift downward? Or is one arm unable to raise up?
- Speech. Ask the person to repeat a simple phrase. Is his or her speech slurred or strange?
- Time. If you observe any of these signs, call an ambulance immediately or run to the hospital.
Time in these cases is crucial since the cells that are without oxygen die by the second. The longer a stroke goes untreated, the greater the potential for brain damage and disability.
Since more specific signs and symptoms depend on the part of the brain affected we will review the signs according to where in the brain the stroke is produced.
If the area affected is somewhere in the central nervous system pathways then the symptoms may include:
- muscle weakness of the face
- reduction in sensory system
- initial flaccidity, spasms, excessive reflexes.
When the stroke happens in the cerebral cortex the following symptoms might appear:
- aphasia (Broca’s or Wernicke’s area)
- dysarthria (motor speech disorder resulting from neurological injury)
- apraxia (altered voluntary movements)
- memory deficits
- disorganized thinking, confusion, hypersexuality gestures (with the involvement of frontal lobe)
Pathways are not only limited to the brain but they are also on the spinal cord, specifically the brainstem bring on the 12 cranial nerves. Therefore, an ictus in the spinal cord and brain, related to the cranial nerves can cause these symptoms even though they are not necessarily an indication of an ictus:
- altered smell, taste, hearing, or vision
- drooping of eyelids and eye muscle weakness
- decreased reflexes
- muscle weakness of the face
- balance problems
- altered breathing and heart rate
- inability to turn head to one side
- inability to stick out the tongue or move it from side to side
If the cerebellum is involved:
Other common symptoms are a loss of consciousness, headache, and vomiting.
Types of strokes
Strokes can be classified into two groups:
1. Ischemic Stroke
Ischemic stroke is caused by a blockage in a blood vessel due to a clot. It is the most frequent, about 85% of the strokes are ischemic. High cholesterol is usually associated with this type since it creates a clot that prevents blood from circulating properly. There is two type of ischemic strokes.
- Thrombotic stroke: This happens when a blood clot, also known as a thrombus, forms in one of the arteries that provide blood to the brain. Plaque or fatty deposits build up in the arteries and reduce blood flow among other.
- Embolic stroke: This happens when the clot is formed away from your brain, usually in your heart, and is carried in your bloodstream and becomes lodged into narrower brain arteries. This clot is called embolus.
2. Hemorrhagic stroke
This type is less common but their sequelae are much more severe. The blood in the artery leaks or ruptures causing bruising and increasing pressure therefore further damage to the neurons. To make it more visual, imagine a very full water balloon on a table full of papers. What will happen when it explodes because the pressure inside the balloon is too high? The balloon will break, water will expand and all of our papers will get wet. Well, more or less happens is the same thing that happens in a hemorrhagic stroke.
It is highly related to high blood pressure (hypertension), overtreatment with anticoagulants and weak spots in blood vessel walls, also known as aneurysms.
There are two types of hemorrhage strokes:
- Intracerebral hemorrhage. In an intracerebral hemorrhage, a blood vessel in the brain bursts and spills into the surrounding brain tissue, damaging brain cells. Brain cells beyond the leak are deprived of blood and also damaged. This can be caused by high blood pressure, trauma and vascular malformations.
- Subarachnoid hemorrhage. In a subarachnoid hemorrhage, an artery on or near the surface of your brain bursts and spills into the space between the surface of your brain and your skull. The sign is usually a severe headache. The common cause is when a small sack-shaped pouch or aneurysm bursts. A vasospasm (widening and narrowing of the blood vessels) causes further damage by limiting blood flow.
3. Transient Ischemic Attack (TIA)
It is also commonly known as a ministroke. This is caused by a temporary decrease in blood supply to different brain parts. It is similar to an ischemic stroke in that a clot is what is causing it, however, it doesn’t leave lasting symptoms because the blockage is temporary. Having a TIA increases your risk of having a full stroke and causing permanent damage. Since it is not possible to determine the difference between a TIA and a full ischemic stroke it is crucial the person seek medical attention immediately.
Diagnosis of a stroke
For a person experiencing the symptoms mentioned above, they need to be treated at a hospital within 3 hours of their symptoms first appearing.
Doctors will perform different exams from physical examination (medical history, symptoms, blood pressure, etc.), blood tests, CT scans, MRI scans, Carotid ultrasound (heart ultrasound), Cerebral angiogram (dyes are injected into the brain’s blood vessels to make them visible under X-ray) and Echocardiogram.
Treatment of a stroke
Treatment is going to depend on the type of stroke:
Since this type is usually because of a clot, then the doctor’s first priority is to restore the blood flow to the brain. For this, they use;
- Aspirin because it prevents blood clots from forming.
- Intravenous injection of tissue plasminogen activator (Alteplase). This drug dissolves the clot but it has to be given within 4.5 hours after stroke symptoms begin.
- Medications delivered directly to the brain. Doctors deliver the alteplase directly to your brain through a catheter.
- Mechanical clot removal. Doctors may use a catheter to maneuver a tiny device into your brain to physically break up or grab and remove the clot. However, recent studies suggest that for most people this procedure may not be the best option. More studies have to be done in order to determine this.
After having a TIA or an ischemic episode the doctor may ask to perform preventive actions to avoid having another stroke:
- Carotid endarterectomy. The doctor removes plaques from arteries that run along each side of your neck to your brain (carotid arteries).
- Angioplasty and stents. The doctor accesses the carotid arteries most often through an artery in the groin and places a balloon to expand the narrowed artery. Then a stent can be inserted to support the opened artery.
The first aspects to treat this stroke is to be aware of the person is taking blood thinners in order to counteract the effects. Other common drugs administered are to lower blood pressure in order to prevent seizures or vasospasms.
Once doctors have controlled this, then the patient has to wait for the body to absorb the excess blood. Much like a bruise, the body will reabsorb it. However, if the bleeding is large, surgery may be required.
When surgery is required it usually entails:
Surgical blood vessel repair.
- Surgical clipping. The doctor puts a tiny clam on the base of the broken blood vessel or an aneurysm to stop blood flow.
- Coiling. The doctor inserts tiny detachable coils into an aneurysm which blocks blood flow and causes the blood to clot.
- Surgical AVM removal. The doctor removes the blood vessel that is malformed in order to lower the risk of another stroke. However, it’s not always possible to remove an AVM if its removal would cause too large a reduction in brain function, or if it is located deep within your brain.
- Stereotactic radiosurgery. Using radiation and it’s the less invasive process.
- Intracranial bypass.
- Optogenetics: “We’re also looking to see if optogenetically stimulating other brain regions after a stroke might be equally or more effective.” “The goal is to identify the precise circuits that would be most amenable to interventions in the human brain, post-stroke so that we can take this approach into clinical trials.” Professor Gary Steinberg
Stroke rehabilitation is the process that patients undergo treatment to help them return to normal life as much as possible by regaining and relearning the skills of everyday living.
Stroke rehabilitation requires a team of multidisciplinary staff that with different skills work together to help the patient regain lost functions. Some of these are doctors, physiotherapists, occupational therapists, speech therapists, neuropsychologists, etc.
Cognitive functions can also be affected by a stroke. CogniFit offers the possibility to assess main cognitive functions and train them adjusted to the patient’s needs.
Risk factors for a stroke
There are a few risk factors to take into account:
- High blood pressure. This is the single most important risk factor for stroke because it’s the leading cause of stroke. It is important that you know your blood pressure and has it checked every year.
- Smoking. This can lead to clots in those blood vessels, causing a stroke.
- Diabetes. Having diabetes more than doubles your risk of stroke. Work with your doctor to manage diabetes.
- High cholesterol. If an artery leading to the brain becomes blocked there is a high risk of a stroke.
- Physical inactivity and obesity. Being inactive, obese, or both can increase your risk of heart disease and stroke.
- Carotid or another artery disease. The carotid arteries in your neck supply most of the blood to your brain if a fatty buildup of plaque happens there can be a clot and cause a stroke.
- Certain blood disorders.
- Excessive alcohol intake.
Prognosis of a stroke
60 percent of patients who suffer an ischemic ictus and 38 percent of hemorrhage ictus survived a year. In total 29 percent of stroke patients are still alive. It is important to lead a healthy lifestyle and always remember the signs and symptoms in order for anyone to receive medical attention as soon as possible.
Do you know anyone that has had a stroke? Don’t hesitate to leave your comments below.