WEDNESDAY, Dec. 1 (HealthDay News) -- A "virtual biopsy" may help diagnose a degenerative brain disorder that can occur in professional athletes and others who suffer repeated blows to the head, says a new study.

Symptoms of chronic traumatic encephalopathy (CTE) can include memory problems, impulsive and erratic behavior, depression and, eventually, dementia. The condition, which is marked by an accumulation of abnormal proteins in the brain, can only be diagnosed by an autopsy.

But a specialized imaging technique called magnetic resonance spectroscopy (MRS) may offer a noninvasive way to diagnose CTE at an early stage so that treatment can begin before further brain damage occurs, say U.S. researchers.

MRS -- sometimes referred to as "virtual biopsy" -- uses powerful magnetic field and radio waves to gather information about chemical compounds in the body.

The researchers used MRS to examine five retired professional male football players, wrestlers and boxers, ages 32 to 55, with suspected CTE and compared them to a control group of five age-matched men.

Compared to the control group, the brains of the former athletes had increased levels of choline, a cell membrane nutrient that signals the presence of damaged tissue, and of glutamate/glutamine (Glx). The former athletes also had altered levels of gamma-aminobutyric acid (GABA), aspartate, and glutamate.

An estimated 3.8 million concussions related to sports and recreation occur in the United States each year, according to the Centers for Disease Control and Prevention.

The study was to be presented Dec. 1 at the annual meeting of the Radiological Society of North America in Chicago.

"By helping us identify the neurochemicals that may play a role in CTE, this study has contributed to our understanding of the pathophysiology of the disorder," Alexander P. Lin, a principal investigator at the Center for Clinical Spectroscopy at Brigham and Women's Hospital in Boston, said in a society news release.

"Being able to diagnose CTE could help athletes of all ages and levels, as well as war veterans who suffer mild brain injuries, many of which go undetected," Lin added.

Because the study is being presented at a medical meeting, its data and conclusions should be viewed as preliminary until published in a peer-reviewed journal.

More information

The American Association of Neurological Surgeons has more about sports-related head injuries.