December 6, 2010

Recognizing Athlete Brain Disease: A New Game Plan

(Ivanhoe Broadcast News) -- Contact sports put athletes at an increased risk of head trauma, which often can lead to an even bigger problem.  Frequent head traumas can lead to a degenerative brain disease called chronic traumatic encephalopathy (CTE), which is impossible to fully diagnose until a postmortem autopsy.  Fortunately, a new imaging method called magnetic resonance spectroscopy (MRS) is being tested to detect the disease at an earlier stage in a study conducted at the Center for Clinical Spectroscopy at Brigham and the Women's Hospital of Boston.

CTE is identified by an accumulation of abnormal brain proteins and is linked to memory problems, impulsive and erratic behavior, depression and dementia.  MRS, also called "virtual biopsy" uses the magnetic field and radio waves of a clinical MR scanner, to locate information regarding chemical compounds within the body.

"Cumulative head trauma invokes changes in the brain, which over time can result in a progressive decline in memory and executive functioning in some individuals," lead investigator Alexander P. Lin, PhD, was quoted as saying.  "MRS may provide us with noninvasive, early detection of CTE before further damage occurs."

Partnering with the Boston University Center for the Study of Traumatic Encephalopathy (CSTE), the researchers looked at five professional male athletes that have retired from sports such as wrestling, football and boxing.  All were suspected of having CTE, and were bound by a similar size, age range (32 to 55) and other control factors.  They were tested with MRS so that brain chemical information could be obtained.

The results showed that former athletes, who were believed to have CTE, contained increased levels of a damaged tissue-signaling cell membrane nutrient called choline.  They also had a higher amount of the amino acid and neurotransmitter glutamate and altered levels of gamma-aminobutryic acid (GABA).  Glutamate's function as an aid in brain functioning is an especially important indicator, as it must be concentrated in specific locations at a certain level to work correctly.

"By helping us identify the neurochemicals that may play a role in CTE, this study contributed to our understanding of the pathophysiology of the disorder," Dr. Lin was quoted as saying.

An estimated 3.8 million sports and recreational-related concussions are reported annually in the U.S., according to the Centers for Disease Control and Prevention.  Early detection could provide beneficial information for many previously injured athletes who are experiencing cognitive problems.

"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," Dr. Lin was quoted as saying.

SOURCE: Radiological Society of North America, December 2010