Signs Of Stroke: Detecting And Preventing Before It Strikes

Strokes are a medical emergency and can often occur without warning. However, in some cases, there may be warning signs that a stroke is imminent. These warning signs, if spotted and treated early, can significantly improve the chances of recovery and reduce long-term issues. So, what are the warning signs, and how can you detect a stroke before it happens?

Weakness or numbness in the face, arm or leg

Experiencing weakness or numbness in the face, arm, or leg is a key warning sign of an impending stroke. This is usually felt on one side of the body.

To determine whether someone is having a stroke, you can ask them to perform some simple actions to test their motor functions. For example, ask the person to smile. If one side of their face is drooping or feels numb, this could be a sign of a stroke.

Another test is to ask the person to raise both arms. If one arm is weak and drifts downward, this could be an indicator of a stroke.

If someone is exhibiting these symptoms, it is important to act quickly. Call 911 immediately and make a note of the time when the symptoms first appeared.

While stroke symptoms often occur suddenly, some people experience warning signs in the days or weeks before a major stroke. For example, one study found that 43% of stroke patients experienced mini-stroke symptoms up to a week before they had a major stroke.

Problems with vision

Vision problems are very common after a stroke, with around 60%-65% of stroke survivors experiencing changes to their vision or vision loss. The type of vision problem that occurs depends on the location of the stroke.

Strokes occur when a part of the brain is starved of oxygen and nutrients. This happens when the blood supply to the brain is interrupted, preventing brain cells from getting oxygen and causing them to die quickly. Strokes can affect the visual pathways of the eye, impacting sight in different ways.

Visual Field Loss

The visual field refers to the entire area that can be seen when the eyes are fixed on a single point, including peripheral vision. Visual field loss, or field cut, is a common problem after a stroke, where a person loses the ability to see part of their field of vision. This can manifest in several ways:

• Hemianopia: Loss of vision in one-half of the visual field, typically affecting either the left or right side in both eyes.
• Quadrantanopia: Loss of vision in one-quarter of the visual field, either the upper or lower quarter.
• Scotoma: A blind spot in one or both eyes, which may occur anywhere in the visual field, including the centre.

Eye Movement Disorders

Damage to the nerves or muscles controlling eye movement can lead to eye movement disorders. Examples include:

• Nystagmus: Rapid and constant movement of the eyes, which may be unsteady or jittery.
• Strabismus: Misaligned eyes, where the eyes turn inward or outward.
• Diplopia: Double vision, which may be treated with prisms or eye patches.
• Oculomotor dysfunction: Issues with eye tracking and convergence.

Visual Processing Problems

Visual processing problems can occur when the brain has difficulty interpreting visual information. This may include:

• Visual neglect or spatial inattention: Unawareness of things on the affected side, due to damage to parts of the brain that perceive and interpret vision.
• Visual agnosia: Difficulty recognising familiar objects, faces, or everyday sights.
• Issues with depth perception, balance, and coordination: Difficulty judging the distance between objects, maintaining balance, and coordinating movements.

Other Vision Issues

Other vision problems that may occur after a stroke include:

• Dry eyes: This can be caused by difficulty blinking or fully closing the eyes, leading to irritation, burning, or blurry vision.
• Light sensitivity: Increased sensitivity to bright lights, glare, or low-light conditions.
• Reading difficulties: Challenges with reading, such as slow reading, difficulty finding the beginning or end of a line, or mixing up similar letters.

It is important to note that vision problems after a stroke may not always be obvious, and a person may not realise they are having vision difficulties. Therefore, it is recommended to have a comprehensive eye examination after a stroke, even if no symptoms are apparent. Early diagnosis and vision rehabilitation can aid in recovery and improve daily activities.

Dizziness and balance issues

While dizziness is a common symptom for people in primary care health settings and emergency departments, recurring episodes of dizziness or vertigo may indicate a more serious underlying condition, such as a stroke.

• Numbness or weakness in the face, arm, or leg, typically on one side of the body
• Trouble speaking or understanding language
• Vision problems in one or both eyes
• Severe headaches with no apparent cause
• Emotional instability or drastic changes in personality

If you or someone you know is experiencing dizziness or balance issues along with any of the above symptoms, it is important to seek medical attention immediately as strokes are a medical emergency. The faster you get treatment, the better the chances of recovery.

Severe headaches

• Weakness or numbness on one side of the body
• Dizziness or loss of balance
• Blurred or double vision
• Slurred speech or difficulty understanding speech
• Nausea or vomiting

The location of the headache pain depends on where the stroke is occurring. For example, a blocked carotid artery can cause a headache on the forehead, while a blockage towards the back of the brain can cause a headache at the back of the head.

It is important to note that not all stroke-related headaches are the same. Some people may experience a "thunderclap" headache, which is a sudden and extremely intense headache. Others may experience a progressive headache that gradually worsens over time.

If you or someone you know is experiencing a severe headache, especially if it comes on suddenly, it is important to seek immediate medical attention. Do not delay in calling 911 or going to the nearest emergency room. Time is critical when it comes to stroke treatment, and early diagnosis and treatment are key for preventing long-term effects.

Transient ischemic attack (TIA) or 'mini-stroke'

A transient ischemic attack (TIA), or mini-stroke, occurs when blood flow to a part of the brain stops temporarily. This can be caused by a blood clot in an artery of the brain, a blood clot that travels to the brain from elsewhere in the body, an injury to blood vessels, or the narrowing of a blood vessel in the brain or leading to the brain.

TIAs are warning signs that a more serious stroke may occur in the future. They are often referred to as "mini-strokes" because they cause similar symptoms to a stroke, such as weakness or numbness of the face, arm, or leg, usually on one side of the body; trouble speaking or understanding; problems with vision; dizziness; and severe headaches. However, unlike a stroke, TIA symptoms are passing and will last from a few minutes to up to 24 hours. After a TIA, the blockage breaks up and dissolves on its own, so a TIA does not cause brain tissue to die.

The National Stroke Association's acronym FAST can help you quickly identify whether someone is having a stroke or a TIA:

• F (Face): Ask the person to smile. Does one side of their face droop?
• A (Arms): Ask the person to raise both arms. Does one arm drift downward?
• S (Speech): Ask the person to repeat a simple phrase. Is their speech slurred or hard to understand?
• T (Time): If you observe any of these signs, call an ambulance immediately.

It is important to take TIAs seriously and seek medical help, even if the symptoms go away on their own. About 4 in 10 people who have a TIA will go on to have a stroke, and there is a 10% chance of suffering a full-blown stroke within three months of a TIA.

Frequently asked questions