The window for successfully administering thrombolysis to patients who have had an ischaemic stroke can be doubled from 4.5 to nine hours, a landmark Australian trial has shown.

This results in more patients making a full recovery with little or no neurological defects, say the researchers, who predict stroke management guidelines will change around the world.

The trial medical co-ordinator, Associate Professor Henry Ma, says the finding is “terrific” news for patients who have experienced a stroke in their sleep.

“These results shift the stroke paradigm from using a clock to determine eligibility for clot-dissolving treatment to using brain imaging to identify whether there is brain tissue that can be saved in the individual patient,” says Professor Ma, a neurologist at Monash Health in Melbourne.