Whispering strokes: A risk factor for future stroke, and what to do about it

Every 40 seconds, someone in the United States has a stroke; every 5 minutes, some dies from one. These alarming CDC statistics make stroke a leading cause of mortality and a major cause of long-term disability for adults. Stroke continues to be an enormous public health burden.

While multiple public health campaigns are aimed at teaching the public to recognize symptoms of stroke and the importance of getting to a hospital quickly, patients are often unaware of asymptomatic stroke, otherwise known as “whispering strokes.” These types of strokes may also be overlooked by clinicians, so it's important to know the ins and outs of this potentially deadly phenomenon.

What are whispering strokes?

In a nationwide study published in Stroke, researchers coined the term “whispering stroke” to denote incidental infarctions found on brain imaging in patients who have not had a clinically recognized stroke. These silent strokes are highly prevalent, affecting approximately 50% of individuals over the age of 85 years. 

Patients presenting with whispering strokes may not be entirely asymptomatic—they may present with clinical symptoms that are not recognized as stroke. Either the symptoms are not pronounced enough for the patient to bring their concerns to a healthcare provider (HCP) or the symptoms were not sufficient for the HCP to reach the diagnosis.

Implications of whispering stroke 

While the term “silent” or “whispering” may suggest that these subtle strokes are benign in comparison to clinically recognized strokes, this may not actually be the case. 

In the aforementioned Stroke study, researchers asked 30,000 Black and White participants about their general health, including if they have experienced any stroke symptoms. Participants rated their physical and mental well-being and their quality of life. 

Individuals with consistent symptoms but without a stroke diagnosis—who accounted for 16% of study participants—had decreased quality of life and declines in both physical and cognitive functioning. 

Whispering stroke may also put patients at heightened risk for a subsequent clinical stroke, highlighting the need for strategies to detect whispering strokes in patients and target them with interventions aimed at preventing stroke. 

Link between atrial fibrillation and whispering stroke

While atrial fibrillation (AF) is associated with a 4- to-5-fold increased risk of stroke, a large, prospective study published in the Journal of the American Heart Association found that one in three adults with AF reported stroke symptoms despite having no official stroke diagnosis. 

The most commonly reported symptoms were sudden numbness and sudden, painless weakness. In contrast, only 17% of study participants without AF reported stroke symptoms, suggesting that stroke symptoms, even in the absence of an official stroke diagnosis, are prevalent among adults with AF. 

Luckily, there might be a way to eliminate the risk of developing stroke symptoms in patients with AF. Investigators found that the potential of having stroke symptoms in this at-risk, but stroke-free cohort, was eliminated by anticoagulant medications and, to a lesser extent, antiplatelet medications. 

Recommendations for clinicians 

To ensure that HCPs do not overlook whispering strokes, thereby placing patients at increased future risk of clinical stroke, investigators recommended that patients be screened for the presence of any stroke symptoms. 

Clinicians can adopt stroke symptom screening as a low-cost prevention strategy suitable for routine primary care, specifically targeting patients with AF who are not receiving anticoagulant therapy, as well as other high-risk populations. 

HCPs can utilize the Questionnaire for Verifying Stroke-Free Status (QVSFS), which has been validated for assessing stroke status. Stroke symptom screening can be accompanied by stroke risk scores such as CHA2DS2‐VASc. 

A positive symptom screen should be followed-up with a thorough stroke workup. 

Additional recommendations 

For patients who have experienced a whispering stroke, secondary prevention measures are arguably similar to those recommended for patients with a clinical stroke diagnosis, although evidence supporting this approach is limited. 

The 2021 Guideline for the Prevention of Stroke in Patients With Stroke and Transient Ischemic Attack included the following recommendations for secondary stroke prevention: 

• Clinicians should focus on management of vascular risk factors, including diabetes, smoking, and hypertension, as well as management of lifestyle factors, including diet and exercise. 

• Patients should be encouraged to exercise and eat a low-salt, Mediterranean-type diet. 

• Antithrombotic therapy, including anticoagulant and antiplatelet agents, is recommended to nearly all patients, with very few exceptions. 

  • However, dual antiplatelet therapy is not recommended in the long term.

• For patients with AF, anticoagulation is typically recommended in addition to heart rhythm monitoring.

Patients will often need more than simple advice from their physician to effect true change in their behavior. This is best tackled by a multidisciplinary team with an approach tailored to each individual patient. 

Sources

1. Stroke facts. CDC. 2021. 

2. Howard G, Safford MM, Meschia JF, et al. Stroke symptoms in individuals reporting no prior stroke or transient ischemic attack are associated with a decrease in indices of mental and physical functioning. Stroke. 2007;38(9):2446-2452.

3. Kleindorfer DO, Towfighi A, Chaturvedi S, et al. 2021 guideline for the prevention of stroke in patients with stroke and transient ischemic attack: a guideline from the american heart association/american stroke association. Stroke. 2021;52(7).

4. Reading Turchioe M, Soliman EZ, Goyal P, et al. Atrial fibrillation and stroke symptoms in the regards study. JAHA. 2022;11(2):e022921.