A silent stroke, also known as an asymptomatic cerebrovascular infarction, is a type of stroke where you don't have recognizable symptoms like facial drooping, arm weakness, or slurring. It can happen while you are awake or sleeping and cause damage to the brain that can permanently affect your thinking, speech, movement, or memory.
Silent strokes may be identified weeks, months, or years later when a person undergoes a brain scan for an unrelated problem. Once diagnosed, a silent stroke should be treated to prevent it from turning into a full-blown stroke.
This article describes how silent strokes are diagnosed as well as the types of symptoms a person might experience. It also explains what should do if you have a silent stroke and how a silent stroke differs from a condition known as a "mini-stroke."
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Think FAST With a Stroke
How Silent Strokes Are Found
A silent stroke is usually diagnosed by chance, either when a person is being examined for an unrelated condition or has mobility or neurologic (brain-related) problems that cannot be explained.
In many cases, a person will have problems with memory, attention, thought processing, or behavior, or experience the unexplained loss of mobility, coordination, or speech. Upon medical imaging, the signs of an old stroke may be seen, including areas of brain atrophy (tissue death) and calcification (deposits of calcium) in or around a ruptured or blocked blood vessel in the brain.
Imaging tests that can diagnose a silent stroke include:
- Magnetic resonance imaging (MRI)
- Computed tomography (CT scan)
- Transcranial doppler ultrasound (TCD)
With an old stroke, tissue scarring may appear as white spots on an MRI or CT scan. A TCD may reveal signs of obstructed or re-routed blood flow.
Common risk factors for a silent stroke include hypertension (high blood pressure), heart disease, diabetes, high cholesterol, and smoking.
How Common Are Silent Strokes?
Silent strokes are more common than classic strokes. According to the American Heart Association, between 8 and 11 million people in the United States experience a silent stroke each year. By age 80, one in four people will have had one or more silent strokes.
A Word From Verywell
A "silent" stroke means that you do not have or do not remember any symptoms. They can cause permanent damage, and if you have more than one, it can lead to problems with thinking and memory.
Do They Have Lasting Effects?
Silent strokes are characterized by a limited area of brain injury and the total (or near-total) absence of symptoms. Many people with a silent stroke will never know that they had one and may go through life without any notable symptoms or consequences.
Some may experience longer-term symptoms that they may not recognize as being stroke-related. Others still may experience a full-blown ischemic stroke or hemorrhagic stroke.
A 2016 study published in the journal Stroke found that a silent stroke increases your risk of a future stroke by more than twofold compared to the general population.
Silent strokes can happen to anyone but tend to affect older adults. Because of this, symptoms are often interpreted as signs of aging and may include:
- Memory problems
- Slowed physical or mental responses
- Loss of balance or coordination
- Problems with speech
- Loss of bowel or bladder control
- Change in personality or mood
- Vision loss in one eye
Symptoms of a silent stroke, such as a loss of memory or cognition, are easily confused with dementia. Ironically, studies have shown that silent strokes may increase the risk of dementia.
Silent Strokes vs. Mini Strokes (TIAs)
A silent stroke is not the same as a mini-stroke. A mini-stroke, otherwise known as a transient ischemic attack (TIA), is a brief stroke-like attack with symptoms that resolve within minutes to hours. Unlike a silent stroke, where there is permanent brain damage, a TIA may improve without any long-term brain damage.
Even so, TIAs are strong predictors of a future stroke. Studies have shown that up third of people who have had a TIA will go on to have a full-blown stroke within one year.
Symptoms of TIA are similar to those of a classic stroke and may include:
- Severe headache
- Dizziness
- Weakness, numbness, or paralysis on one side of the body
- Slurred speech
- Difficulty understanding others
- Blindness in one or both eyes
If TIA is diagnosed, preventive therapies would be used to reduce your risk of a future stroke.
What Should I Do?
If you have had a silent stroke, it is important to not only engage in treatments to aid with rehabilitation and recovery but also to make lifestyle changes to prevent a full-blown stroke in the future.
Rehabilitation and Recovery
Recovery from a silent stroke may involve multiple providers and treatments to get you functioning normally (or as normally) as possible following your diagnosis.
This may involve:
- Physical therapy to help you relearn motor and coordination skills you may have lost
- Occupational therapy to help better manage daily activities such as eating, drinking, dressing, bathing, and writing
- Speech therapy to help overcome problems producing or understanding speech
- Strength training with a personal trainer or physical therapist to improve lower extremity weakness
- Memory games to help overcome cognitive impairment that can sometimes occur with stroke
- Psychotherapy to deal with depression, anxiety, or self-esteem issues common in people with stroke
- Online and in-person support groups that allow you to share your feelings and seek advice and referrals from others who understand what you are going through
Prevention
It is important to take steps to prevent a future stroke irrespective of how long ago the silent stroke may have occurred. Tissue damage in the brain inherently weakens blood vessels or causes them to narrow, both of which can contribute to a stroke. This is true even if you've never experienced any symptoms and feel perfectly fine.
Preventive treatments may involve:
- A healthy, Mediterranean diet (based on foods such as whole grains, fruits, vegetables, nuts, and olive oil).
- Routine exercise, including appropriate aerobic activities
- Weight loss if you are overweight or have obesity
- Controlling your blood sugar
- Quitting cigarettes (which cause the narrowing of blood vessels)
- Anticoagulants (blood thinners) to prevent the formation of clots (which are always prescribed to people with a TIA or ischemic stroke, including a silent ischemic stroke)
- Statin drugs to reduce high cholesterol levels which can lead to clogged arteries
Regular check-ups with a cardiologist are also recommended to monitor your condition and adjust treatment as needed.
Summary
A silent stroke is one in which you have no notable symptoms and may not even realize that you had it. Even so, it can cause damage to the brain and potentially serious symptoms in later life, including an increased risk of dementia or a full-blown stroke.
A silent stroke is often diagnosed by chance during a brain scan for an unrelated condition or symptoms you cannot explain. Once diagnosed, a silent stroke needs to be treated with lifestyle changes and medications to prevent a future stroke.