The research, published this month in the Annals of Neurology, is the first step in a multiyear project assessing how to predict how well people will recover from stroke. Researchers will repeat the brain scanning and behavioral testing months after the patients' strokes to see how both change over time.

Carter and others ultimately aim to use the technology to better target stroke treatments. "It's important to know what lies behind recovery, because we want to have a brain-based understanding of new treatments," says James Rowe, a neuroscientist at Cambridge University, in the U.K., who was not involved in the study. In addition, he says, because this kind of scan can be done very early, "we might be able to classify patients who would benefit from one type of therapy or another."

Two patients who have similar motor impairments might actually have very different disruptions to their brain networks and therefore benefit from different types of treatment. For example, not everyone responds to constraint-induced movement therapy, in which the strong arm is bound, forcing the patient to use their weak arm. Analysis of network dysfunction might help predict which patients will benefit from this treatment.

The research is part of a broader effort to capitalize on the inherent neural plasticity that is present even in the adult brain. "There is more and more interest in changes in the brain that occur at more chronic stages of stroke," says Rick Dijkhuizen, a neurobiologist at University Medical Center Utrecht, in the Netherlands, who was not involved in the current work. "Increasing evidence suggests that the brain is able to reorganize even in patients [whose strokes occurred a long time ago], and this gives us opportunities to look at stroke therapies to promote this organization."