CHICAGO (AP) -- New research shows children with even relatively mild concussions can have persistent attention and memory problems a year later.

Most kids recover soon after injury but the study helps identify which ones may be most at risk for lingering symptoms. Forgetfulness, headaches and fatigue were more common in kids who lost consciousness. They were also more common in children who had other mild head trauma that caused brain abnormalities visible on imaging tests.

The results suggest problems may linger for months in up to about 20 percent of kids with mild concussions or other mild brain injuries.
Problems like forgetfulness were more likely to linger than physical complaints.

The study was published online Monday in Archives of Pediatrics & Adolescent Medicine.