Published in UAB Insight, Winter 2008
Events Are Overlooked and Damaging
New results from REGARDS (Reasons for Geographic and Racial Differences in Stroke) have prompted its UAB investigators to introduce the term “whispering stroke” to describe symptomatic but undiagnosed strokes, which they have found may affect as many as 1 in 5 Americans older than 45 years.
REGARDS, a UAB-led, multicenter effort funded by the National Institute for Neurological Disorders and Stroke, aims to determine why stroke mortality disproportionally affects blacks and people from the Southeast. The national population-based study recently reached its recruitment goal of more than 30,000 black and white adults aged ≥45 years. Investigators suspected that prevalence of undiagnosed stroke could be higher than reported after finding a substantial number of stroke symptoms among study participants without a prior diagnosis of stroke or transient ischemic attack (TIA).
Researchers asked about six symptoms: sudden painless weakness on one side of the body; sudden numbness or a dead feeling on one side of the body; sudden painless loss of vision in one or both eyes; sudden loss of one-half of vision; sudden loss of the ability to understand what people are saying; and sudden loss of verbal or writing abilities or both.
Almost 18% of surveyed participants who reported never having been told by a physician or health professional that they had either a stroke or a TIA reported at least one stroke symptom. Two important predictors of symptoms were black race and high Framingham Stroke Risk scores — both major predictors of stroke events. Those with low income, limited education, and health they perceived as fair to poor (compared with excellent to good) also were more likely to experience stroke symptoms (Arch Intern Med. 2006;166:1952-1958). REGARDS investigators hypothesized symptoms might indicate whispering strokes or TIAs that, like clinically apparent strokes, would leave patients with cognitive and physical deficits (Stroke. 2007;38:1143-1147).
“Those with stroke symptoms but no diagnosis of stroke had odds of cognitive impairment that were about one third higher than those without either a stroke diagnosis or a history of symptoms,” says UAB Chair of Biostatistics and REGARDS principal investigator George Howard, DrPH. “Subsequent research has shown that people who report these symptoms have substantially lower quality of life — particularly in regard to their physical functioning — than those who are free from them,” he says.
Investigators found that about half of people who experience stroke symptoms do not see a doctor at symptom onset. “People with low income were least likely to seek health care when symptoms occurred, while those with cardiovascular risk factors such as hypertension and diabetes tended to discuss symptoms with their doctors,” he says.
REGARDS investigators are continuing research into the risks of whispering stroke, Howard says, noting that “an examination of the relationship between stroke symptoms and mortality is turning up interesting findings.” In 2008 the REGARDS study received $20.8 million for an additional 5 years of research to assess health endpoints, cognitive functioning, quality of life indicators, and measures of discrimination in stroke care.
“People cannot have fever unless you take their temperature,” he says. “Physicians do not generally ask about stroke symptoms, and questioning patients 45 years and older about these symptoms could help identify those with an undiagnosed whispering stroke.”
For more information:
Dr. George Howard
1.800.UAB.MIST
mist@uabmc.edu