Silent strokes are small strokes that may occur in a part of the brain that doesn’t cause visible symptoms. But multiple silent strokes can still cause significant brain damage and increase your risk of a major stroke.
Is it possible to have a stroke and not know it?
Yes. You can have a “silent” stroke, or one you’re completely unaware of or can’t remember.
When we think of strokes, we often think of symptoms like slurred speech, numbness, or loss of movement in the face or body. But silent strokes don’t show symptoms like these. In fact, silent strokes usually display no symptoms at all.
What causes a silent stroke?
Like ischemic strokes, silent strokes happen when blood supply to a part of your brain is suddenly cut off, depriving your brain of oxygen and damaging brain cells.
Contributing factors to a silent stroke include:
blood clots
high blood pressure
narrowed arteries
high cholesterol
diabetes
But a silent stroke is, by nature, hard to recognize. That’s because a silent stroke disrupts blood supply to a part of your brain that doesn’t control any visible functions like speaking or moving, so you might never know a stroke occurred.
These strokes are usually lacunar strokes, meaning they occur in the brain’s smaller blood vessels.
According to a 2016 review, about 18%Trusted Source of older adults who have not had a symptomatic stroke have had a silent stroke.
The way most people find out they had a silent stroke is when they have an MRI or CT scan for another condition and doctors notice brain damage to small areas of the brain.
Are silent strokes less dangerous than other strokes?
Just because you don’t know a silent stroke happened doesn’t mean the damage is insignificant.
Silent strokes generally only affect a small area of the brain, but the damage is cumulative. If you’ve had several silent strokes, you may begin noticing neurological symptoms. For example, you might begin to have trouble remembering things or concentrating.
According to the American Stroke Association, silent strokes also increase your risk of having a symptomatic stroke in the future. The 2016 review mentioned above notes that the risk is doubled.
Researchers have also confirmed that having multiple silent strokes puts you at risk for vascular dementia, also known as multi-infarct dementia. Symptoms of vascular dementia include:
memory problems
emotional issues, like laughing or crying at inappropriate times
changes to your way of walking
getting lost in places that should be familiar to you
trouble making decisions
losing bowel and bladder control
What’s the difference between a silent stroke and a TIA?
A transient ischemic attack (TIA), also known as a ministroke, is a temporary disruption of blood flow to a part of the brain. While silent strokes don’t have any symptoms, TIAs cause symptoms lasting less than 24 hours.
Symptoms of a TIA include:
trouble walking
blindness in one eye or cuts in your field of vision
sudden, severe headache
dizziness
confusion
The temporary nature of a TIA means that it causes no permanent damage. But with silent strokes, the damage is permanent. The effects of multiple silent strokes can accumulate to cause significant damage.
Both TIAs and silent strokes can increase your risk of major strokes (ischemic or hemorrhagic) in the future.
Silent stroke | TIA | Ischemic/hemorrhagic stroke | |
Symptoms | No | Less than 24 hours | More than 24 hours |
Brain damage | Yes | No | Yes |
Increases future stroke risk | Yes | Yes | Yes |
How can you tell if you’ve had a silent stroke?
If you have a brain CT scan or an MRI, the image will show white spots or lesions where your brain cells have stopped functioning. That’s how doctors will know you’ve had a silent stroke.
Other nonspecific symptoms are so subtle that they’re often mistaken for signs of aging, like:
balance problems
frequent falls
urine leakage
changes in your mood
decreased ability to think
Can you recover and reverse the damage from a silent stroke?
There’s no way to reverse permanent damage done to brain cells from the lack of oxygen.
However, in some cases, healthy parts of your brain may take over the functions that used to be performed by the damaged areas. Eventually, if the silent strokes continue, your brain’s ability to compensate will decrease.
Can you treat cognitive issues?
According to the National Institute of Neurological Disorders and Stroke, rehabilitative therapy can help people who have lost some of their abilities due to stroke. Professionals that can help you regain function include:
physical therapists
occupational therapists
speech-language pathologists
mental health professionals
While there are no approved medications to treat vascular dementia, some doctors prescribe Alzheimer’s medications, such as:
donepezil (Aricept)
galantamine (Razadyne)
rivastigmine
You can do many small, practical things to help your memory if silent strokes have impaired your cognitive abilities. Try these steps:
Practice routines for completing specific tasks at certain times of the day.
Create habits for putting things you need, like medication and keys, in the same spot every day.
Make to-do lists and instruction lists to help you remember the steps to complicated tasks.
Use a pill box to help you keep track of medications.
Set up direct payments of your bills so you don’t have to memorize due dates.
Play memory games to sharpen your skills.
Can you prevent silent strokes?
Yes. While it’s hard to spot a silent stroke and even harder to restore areas of the brain affected by it, it’s relatively easy to prevent one from happening.
Experts recommend the following preventive strategies:
Manage your blood pressure, blood sugar, and cholesterol.
Stay physically active.
Reduce your salt intake.
Maintain a moderate weight.
Avoid smoking.
Eat a heart-healthy diet.
Ditch the diet drinks.
Should I see a doctor?
A stroke is a dangerous medical event. If you’re experiencing any of the symptoms of a stroke, get immediate medical attention.
If you aren’t having stroke symptoms but you’re at risk for a silent stroke, contact a doctor. They can help you develop a plan to reduce your risk factors and prevent a stroke.
The bottom line
A silent stroke has no noticeable symptoms, but it can still do damage to your brain.
Like regular ischemic strokes, silent strokes happen when the blood supply gets cut off to a small area in the brain, damaging the brain cells. Silent strokes have cumulative effects on the brain’s health and your physical and mental abilities.
You can reduce your risk of having a stroke by:
exercising
eating healthy foods
managing your weight
reducing cholesterol levels to be in the target range
limiting salt intake
If you’re concerned about silent strokes, talk with a doctor about changes you could make to prevent them.