In research that could one day significantly cut recovery times for victims of these debilitating brain injuries, scientists have injected modified stem cells into the brains of patients and brought about substantial improvements to motor function, with one even regaining control of her limbs and leaving her wheelchair behind.

Around 15 million people suffer a stroke each year, according to the World Stroke Organization. The majority of these are classed as ischemic, which means that a clot has formed in a vessel carrying blood to a section of the brain to cut of its supply.

Immediate treatment to dissolve the clot in an ischemic stroke will boost the chances of a full recovery, but with only three or four hours to get to a hospital to have the clot-busting drugs administered, many victims miss this critical window and wind up sustaining lifelong disabilities.