"Whispering strokes" often go unheard, but still cause damage

Stroke symptoms are common among people older than 45, but many of these patients never receive a diagnosis or related medical care. Their untreated array of symptoms -- termed "whispering strokes" in a study published in the Aug. 2 Stroke -- can lead to a lower quality of life and declines in physical functioning comparable to that from a confirmed transient ischemic attack. Cognitive problems also are worse in this population, according to the study.

"These results show a need for greater awareness of stroke symptoms and a need to take these symptoms seriously," said George Howard, DrPH, lead author and the chair of biostatistics at the University of Alabama at Birmingham's School of Public Health.

Researchers analyzed questionnaires about mental and physical status completed by 21,803 participants of the Reasons for Geographic and Racial Differences in Stroke project. Previous papers from this effort found that 7% of participants had a diagnosis of TIA or stroke, but 18% had symptoms without a diagnosis. The authors hope that this more recent publication will lead to increased emphasis on milder symptoms. They also hope that these patients will receive treatment to reduce their risk of having a more debilitating event.

"The best way to treat a stroke is to prevent it from ever happening," Dr. Howard said.

Experts praised this paper for bringing attention to what many suspect is the largely unrecognized area between the silent strokes, which are detected on imaging but have no or minimal symptoms, and the frank strokes, which can be so destructive.

"It's quite important and shows that a stroke symptom is a pretty good marker of not only having damage in the brain but other comorbidities as well," said Tobias Kurth, MD, ScD, an epidemiologist at Brigham and Women's Hospital and assistant professor of medicine at Harvard Medical School in Boston.

The question now is why such incidents are not diagnosed. Future papers from this project are expected to answer this query, though there are several possible explanations. Patients may not consider symptoms, particularly if they are mild or resolved quickly, serious enough to seek medical attention. Doctors may not think of stroke when less severe symptoms are the principal complaints.

"The subjects themselves might have dismissed symptoms as not being important and never mentioned them to a health care provider. They could have mentioned them, but the health care provider dismissed them as not important or never discussed them using the terms stroke or TIA," said Larry B. Goldstein, MD, director of the Duke University Center for Cerebrovascular Disease in Durham, N.C.

In response to these suspicions and the increasing evidence that mild or transient stroke-like symptoms can have a long-term impact, experts are urging physicians to be more aggressive in eliciting information about such incidents and initiating measures that reduce the risk of a full-blown stroke.

"What we need to do is take whispering strokes to another level of awareness so that an individual patient will bring symptoms to a physician's attention, and physicians will ask the question about transient episodes of weakness or numbness," said Edgar Kenton, MD, a neurologist in Atlanta and immediate past chair of the American Academy of Neurology's practice panel. "We want to get them before they have the big one."

But although there was a lot of interest in this project's findings, there was some doubt that the high prevalence reflected the true number of undiagnosed strokes. Some questioned how easily this study could be generalized because half the participants live in the eight states with the highest stroke rates. Also, determination of an undiagnosed stroke was made by asking patients about symptoms -- some of which can be indicative of other disorders -- but did not include any confirmation by imaging.

"There's really no correlation with any type of physical exam finding or imaging and no confirmation that these subjective neurologic deficits are actually associated with true functional deficits. It's not just stroke that gives rise to weakness or numbness or neurologic symptoms," said Peter P. Toth, MD, PhD, a family physician and director of preventive cardiology at the Sterling Rock Falls Clinic Ltd. in Sterling, Ill.