One in seven strokes happen at night, and patients may not get medicine that could prevent brain damage, a new study suggests.
"These kinds of strokes are common -- about 15% of all strokes. That's a substantial amount of people," says study author Jason Mackey, a stroke researcher at the University of Cincinnati.
Mackey says "wake-up" stroke sufferers are more likely to miss out on a potentially lifesaving clot-busting medication called tissue plasminogen activator, or tPA, that can be given only within the first few hours after stroke symptoms begin. Given beyond that window, it could cause complications.
For the study, published today in the journal Neurology, researchers analyzed data from 1,854 patients over 18 who had been treated in hospital emergency departments in Greater Cincinnati and Northern Kentucky over the course of a year for ischemic strokes. Ischemic strokes are caused by clots in the arteries of the brain that block blood flow, and they are the most common type of stroke.
Mackey and his colleagues found that 273 patients experienced wake-up strokes. When translated to the greater population, that suggests about 58,000 people a year, he says.
Even though it's difficult to know when a wake-up stroke first occurred, getting speedy medical care is crucial. "The most important thing is if you suspect you're having a stroke, call 911," he says.
One reason: Newer imaging technologies at some hospitals can help doctors determine whether urgent treatments can still help a patient who has had a stroke while asleep, says Ausim Azizi, professor and chairman of the department of neurology at Temple University School of Medicine in Philadelphia.
"There are imaging technologies that can show if there's brain tissue left that is not completely dead and can be salvaged," he says. There is also a catheter procedure that can help remove clots seen on scans.
At least 98 of the people in the study who had wake-up strokes would have been eligible for tPA, researchers said.
"No matter what, still the best thing to do is to go to the hospital," Azizi says -- and by ambulance. He says not all emergency rooms have tPA on hand or a stroke expert on call, and if an ambulance team realizes you're having a stroke, you can be rerouted to the nearest emergency room equipped to treat stroke patients.
"This is a group of patients that should be a focus for future studies," Mackey says. "It's likely that some of these strokes occurred immediately prior to awakening, and people would benefit from treatment."