Clot-busting drugs may be safe for wake-up stroke patients
Clot-busting drugs may be safe for patients who wake up experiencing stroke symptoms, according to preliminary research presented at the American Stroke Association’s International Stroke Conference 2012 in New Orleans.

“Because wake-up strokes are common, occurring in up to a quarter of stroke sufferers, more research is needed on how to treat these patients,” Dulka Manawadu, MD, stroke medical consultant at King’s College Hospital in London, said in a statement.

In “wake-up” stroke, the person wakes up with symptoms after going to sleep with none. Not knowing when the stroke began excludes these patients from anti-clotting drugs that must be given within 4.5 hours of stroke onset.

While some doctors are reluctant to give clot-busting drugs to wake-up stroke patients with an unknown time of stroke onset, it’s possible the patient suffered the stroke within the window of time for effective treatment. Advanced imaging techniques may help to identify patients with wake-up stroke who have the potential to benefit from clot-busting drugs.

Manawadu and colleagues used a stroke registry to compare clot-busting treatments received by 326 patients within 4.5 hours of symptom onset to 68 wake-up stroke patients, with unknown onset, between January 2009 and December 2010. Patients received the clot-buster alteplase, sold under the name Activase. Wake-up stroke patients received the clot-busting treatments if their clinical presentation and early stroke changes on CT scan images were comparable to those treated with a known time of onset.

After three months, the researchers found the wake-up stroke patients’ death rates, risk of bleeding inside the brain and the proportion that made a good recovery were similar to those patients treated within a known 4.5 hours of stroke onset.

“Our study shows that administering clot-busting drugs to patients with wake-up stroke who have the same clinical and imaging features as those treated within current guidelines is feasible and safe,” Manawadu said.

One limitation of the study is the treatments were not randomized and wake-up stroke patients received alteplase on compassionate grounds with consent. In the study abstract, the authors wrote that the results of this preliminary study support the need for future, randomized trials.

“This is an area of growing importance because it may allow us to extend the indication for this effective treatment,” Manawadu said. “Research has been limited to date but the time is ripe to investigate effective treatments in this group of patients.”

A study published online Oct. 5, 2011, in Lancet Neurology indicated that diffusion-weighted MRI may help inform the stroke treatment timeline and possibly lead to development of an imaging biomarker to define a tissue window for stroke thrombolysis.

To learn more about telestroke programs, please read "Telestroke Networks Make a Mark," published in the November 2011 issue of Health Imaging.