Wake-up strokes frequent, ineligible for thrombolysis
MedWire News: About 14% of patients with ischemic stroke find symptoms present on waking, shows a population-based study.
Patients with wake-up stroke are not eligible for intravenous thrombolytic therapy, which has a 3-hour therapeutic window and therefore requires knowledge of the time of symptom onset.
"This is a group of patients that should be a focus for future studies," said lead researcher Jason Mackey (University of Cincinnati, Ohio, USA). "It's likely that some of these strokes occurred immediately prior to awakening, and people would benefit from treatment."
Mackey and colleagues report 273 (14.3%) wake-up strokes among 1854 stroke hospitalizations identified during 2005 in the Greater Cincinnati/Northern Kentucky Stroke Study.
This gave a wake-up stroke rate of 2.6 per 100,000 people after adjusting for age, gender, and race according to the 2000 US Census, they report in the journal Neurology.
Patients with wake-up stroke were slightly older than those with stroke onset while awake, at 72.3 versus 70.0 years. They also had slightly greater neurologic impairment, with median retrospective National Institutes of Health Stroke Scale scores of 4 versus 3, respectively.
But other characteristics, including comorbidities and whether patients lived at home and with a partner, did not differ according to whether or not patients had wake-up stroke.
If time of onset was disregarded, 35.9% of patients with wake-up stroke would have been eligible for thrombolysis, after accounting for other exclusion criteria, say Mackey and team. This was a significantly higher proportion than the 25.0% of patients who had stroke onset while awake, they add.
"Based on extrapolation from our data, we estimate that approximately 58,000 patients with wake-up ischemic strokes presented to an emergency department in the USA in 2005," say the researchers.
They add: "Efforts are ongoing to develop better methods of identifying those patients most likely to benefit from treatment while at the same time minimizing exposure to undue risk."
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By Eleanor McDermid