After years of studies and high-profile cases, head injuries to athletes are getting the serious attention that may force major changes.

Recent hearings by the House Judiciary Committee centered around criticism of National Football league officials for their concussion-related policies, and two members of the NFL’s brain-injury commission resigned late last year. Those events coincided with the league’s decision to institute stricter guidelines for returning to play for players showing concussion symptoms and a requirement that teams use independent neurologists for advice.

The Congressional committee isn’t done. It plans to conduct a forum this month exploring how high schools and colleges handle concussions.

Concussions are a hot topic in the National Hockey League as well. The NHL’s 30 general managers agreed last year to form a committee to investigate the problem before they meet again in March. One proposed rule under consideration is a prohibition against contact with the head.

Outside of sports leagues, work also is under way on how to prevent and treat concussions. University at Buffalo researchers, for instance, published a study in January showing that a controlled, individualized exercise program can help relieve the symptoms of post-concussion syndrome in athletes and others.

Their results, reported in the Clinical Journal of Sport Medicine, counter accepted wisdom that the syndrome’s symptoms, including headaches and dizziness, should be treated with rest, antidepressants and the avoidance of physical activity.

As many as 3.8 million concussions related to sports and recreation occur each year, according to the federal Centers for Disease Control and Prevention.