About 1 in every 7 occurrences of stroke happen while the patient is sleeping, resulting in ineligibility for life-saving clot-busting treatment, researchers from the University of Cincinnati wrote in the journal Neurology. Clot-busting treatment has to be given within a few hours of first symptoms appearing.
Jason Mackey, MD, said:
"Because the only treatment for ischemic stroke must be given within a few hours after the first symptoms begin, people who wake up with stroke symptoms often can't receive the treatment since we can't determine when the symptoms started. Imaging studies are being conducted now to help us develop better methods to identify which people are most likely to benefit from the treatment, even if symptoms started during the night."
Dr. Mackey and team gathered data on all patients aged 18+ who were treated for ischemic stroke in the Greater Cincinnati/Northern Kentucky region over a period of 12 months. Ischemic strokes occur when the blood flow to the brain is blocked; it is the most common form of stroke.
In 14% (273) of the 1,854 cases of ischemic stroke examined, the patient's stroke occurred while they were asleep ("wake-up strokes"). The researchers extrapolated that nationally there are about 58,000 wake-up strokes each year.
They compared the wake-up stroke patients with those whose symptoms started while they were awake. The two groups were similar regarding gender, marital status, plus stroke risk factors, such as hypertension, smoking, high cholesterol or diabetes.
There was a slight link between age and stroke severity. The wake-up stroke patients had an average age of 72, compared to 70 for the other individuals. The average score of the wake-up stroke patients was four, compared to three among those whose symptoms started while they were awake. A mild stroke has a score of one to four.
At least 98 of the 273 wake-up stroke patients would have been eligible for clot-busting drug tissue plasminogen activor (iPA), if it had been available during the time of stroke onset, the researchers added.
Dr. Mackey said:
"This is a group of patients that should be a focus for future studies. It's likely that some of these strokes occurred immediately prior to awakening, and people would benefit from treatment.""Population-based study of wake-up strokes"
J. Mackey, MD, D. Kleindorfer, MD, H. Sucharew, PhD, C.J. Moomaw, PhD, B.M. Kissela, MD, K. Alwell, BSN, M.L. Flaherty, MD, D. Woo, MD, P. Khatri, MD, O. Adeoye, MD, S. Ferioli, MD, J.C. Khoury, PhD, R. Hornung, DPH and J.P. Broderick, MD
Neurology May 10th. doi: 10.1212/WNL.0b013e318219fb30
Written by Christian Nordqvist