The researchers also used magnetic resonance spectroscopy (MRS), a technique that measures levels of chemicals and neurotransmitters in the brain. "It's like a virtual biopsy of the brain, because we get to see a spectral analysis of various biochemical metabolites without invasively going into it," says Robert Stern, co-director of CSTE and an associate professor of neurology at BU School of Medicine. "The study showed some very striking and significant differences between the athletes and the controls when it comes to certain chemicals," Stern says. He did not want to comment on the specific chemical differences, however, because it was only a pilot study.

The brains of all five of the athletes' with a history of head impacts were abnormal in one way or another, says Nowinski. But this does not necessarily mean that the subjects have CTE. "That is the point of the larger study, to figure out if the abnormalities mean anything," he says.

The larger study will include a group of retired NFL players that the researchers consider to be at the greatest risk of developing CTE, and a group of retired athletes that played noncontact sports and have no history of repetitive brain injury. In addition to imaging players' brains using DTI, MRS, and advanced MRI, the researchers will take DNA, blood, and spinal fluid samples to look for genetic risk factors. They will also conduct clinical and neurological examinations and neuropsychological tests. The disease symptoms include memory problems, impulse control, depression, apathy, and problems with cognitive skills like planning.

"While we know that repetitive brain trauma is a necessary variable, it is not a sufficient variable," says Stern. In other words, the researchers don't know why some people who experience repetitive brain trauma get the disease while others do not, and they don't know how many hits, or what types of hits, may cause the disease.

By combining different tools, the BU researchers expect to be able to detect and diagnose CTE within five years. CSTE has over 73 brains in its brain bank, with over 360 athletes committed to donating theirs after they die. Stern also confirmed that the center is receiving the brain of 28-year-old NHL player Derek Boogard, who was found dead in his apartment on May 13. He was recovering from a season-ending traumatic brain injury. The center has also found evidence that the two former NHL players it has examined had CTE.

"Advanced imaging techniques are the future of early diagnosis," says Gunnar Brolinson, associate dean for clinical research for the Virginia College of Osteopathic Medicine and the physician for Virginia Tech's football team. Until then, Brolinson says, "you have to take the head out of the game by making better rules and educating players, coaches, and parents on head injuries."

The NFL made significant rule changes last season with this in mind—harsher penalties and heavy fines for helmet-to-helmet hits or hits against defenseless players.