Silent Stroke: Symptoms, Causes, and Why it Matters

Every year, an estimated 8 to 10 million Americans suffer a stroke and don’t even know it. Referred to as “silent strokes,” this type of stroke doesn’t cause noticeable symptoms but still damages the brain. Many people don’t realize they’ve had one until it shows up on a brain scan. Even without warning signs, silent strokes can increase your risk of memory loss, cognitive decline, and future strokes 

What Are the Symptoms of a Silent Stroke?

According to Rajiv Padmanabhan, MD, a neurologist with the Department of Neurology at Baystate Health, “Like other types of strokes, a silent stroke is caused by a loss of blood flow to an area of the brain. What makes these undetectable, or silent, is that they occur in an area of the brain that doesn’t control essential functions like speech or walking. Very often, the symptoms of a silent stroke are mistaken for naturally occurring signs of aging.”

Common symptoms of a silent stroke include:

• Rapid changes in mood or personality
• Issues with cognitive skills or ability
• Failing memory
• Sudden lack of balance
• Temporary loss of muscle movement

The only way to confirm a silent stroke is through imaging including an MRI or CT scan.

Dr. Padmanabhan notes that, “While you might miss the signs of a silent stroke, that doesn’t mean it’s not causing harm.”

Why Are Silent Strokes Dangerous?

One of the most concerning aspects of a silent stroke is the fact that once you’ve suffered one, your chances of suffering more strokes in the future increase. In fact, the American Stroke Association estimates that one in four people over 80 has evidence of one or more silent strokes. Dr. Padmanabhan says, “When someone experiences a series of silent strokes over time, it can lead to cognitive disabilities. Family and friends might notice challenges with reasoning, planning, judgment, memory and other thought processes all caused by the interrupted flow of blood to the areas of the brain affected by silent stroke. This type of damage could result in vascular dementia in the long term.”

How to Reduce Your Risk of Silent Stroke

While strokes—silent or otherwise—can’t be predicted, you can take steps to reduce your risk.

The good news is that risk factors and preventative measures are the same for all types of strokes, meaning any lifestyle changes you make to prevent a silent stroke will also work to prevent other types of strokes.

What Are the Risk Factors for a Stroke?

High blood pressure: If you have high blood pressure, work with your doctor to get it under control and be consistent about taking any prescribed medication.

Sleep apnea: Can raise your risk of high blood pressure, diabetes, and depression. These conditions can also increase your risk of stroke. If you often wake up feeling unrefreshed or feel very sleepy during the day, it could be a sign of sleep apnea. Talk with your healthcare provider to see if a sleep study is right for you. In many cases, this test can be done in the comfort of your own home.

Atherosclerosis (artery diseases): With atherosclerosis, fatty material, or plaque, builds up on the inner wall of the arteries. Sometimes plaque breaks loose causing clots throughout the body, including the brain. Medications for atherosclerosis range from aspirin and high blood pressure pills to statin and cholesterol drugs. If you’re prescribed one or more of these medications, take them as recommended by your doctor.

Atrial fibrillation:A heart rhythm disorder, atrial fibrillation—or Afib—increases stroke risk by 5 times. If you have Afib, work with your doctor to get it under control and adopt a healthy lifestyle.

High cholesterol: Too much cholesterol in your blood can cause fatty deposits to build up in your arteries and can increase your risk of a blood clot which could cause a stroke. You can lower your risk by lowering your cholesterol through diet and lifestyle changes or with medication prescribed by your doctor.

Lifestyle Changes to Reduce Stroke Risk

Quitting smoking: If you smoke, quit. If you don’t smoke, don’t start. Smoking, and even inhaled secondhand smoke, works to make blood “sticky” and more likely to clot. Quitting smoking and reducing exposure to secondhand smoke immediately reduces your risk of a stroke and cardiovascular disease.

Stay active: Movement improves circulation and increases overall health. Aim for 30 minutes of movement five days a week. This might include taking a fitness class or simply walking the dog.

Embrace a Mediterranean Diet: High in fiber and fresh fruits and vegetables and low in fats, cholesterol and sodium, a Mediterranean diet has been shown to reduce risk of stroke by 13% overall and as much as up to 22% in women.

Manage your stress: Over time, stress contributes to stroke-related risk factors including high blood pressure, poor sleep habits, and increased fat levels in your blood. Look for ways to manage your stress and reduce your risks. Things as simple as practicing deep breathing, getting up from your desk throughout the day, structured classes in meditation and talking with a therapist can all work to help you take control of your stress and health.

When Should You See a Doctor

If you have risk factors like high blood pressure, diabetes, or heart disease, or notice subtle changes in memory or thinking, talk to your doctor or contact our neurology team. Silent strokes are often found after they happen, but early evaluation can help reduce your risk of a more serious stroke. Call 911 right away if you experience sudden symptoms like face drooping, arm weakness, or trouble speaking.