A Better Option Than Cutting Open Your Brain

"Virtual Biopsy" shows promise in diagnosing CTE while alive

/ Author:  / Reviewed by: Joseph V. Madia, MD

Mike Webster. Terry Long. Andre Waters. Justin Strelczyk. Chris Henry. Those names, along with many others, might not mean anything to someone who doesn't closely follow the National Football League.

But all were former players, all died under the age of 50, and more distressing, all suffered from varying degrees of amnesia, depression, confusion, and in the cases of Long and Waters, suicide. 

Upon autopsy, all those players were determined to have suffered from Chronic Traumatic Encephalopathy (CTE), a degenerative disease caused from incurring repeated concussions and head injuries, and which results in the above mentioned disabilities. Currently the only way to diagnose the condition of Chronic Traumatic Encephalopathy is a post-mortem examination of the brain tissue. But that may be about to change. 

A study was recently presented at the annual meeting of the Radiological Society of North America that showed an imaging technique called magnetic resonance spectroscopy (MRS) may be able to diagnose CTE while patients are still alive. Researchers at the Center for Clinical Spectroscopy at Brigham and Women's Hospital in Boston who performed the study believe this “virtual biopsy” will allow for early diagnosis and better treatment of the patients. 

"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. MRS may provide us with noninvasive, early detection of CTE before further damage occurs, thus allowing for early intervention." remarked Alexander P. Lin, Ph.D., a principal investigator of the study. 

In the study, the investigators looked at five former professional athletes: three football players, a boxer, and a wrestler, all aged between 32 and 55 years old. The athletes had all been diagnosed with concussions during their three to fifteen year playing careers. They were compared to five other men of similar ages who had no concussion histories. All ten patients underwent screening with MRS, which unlike magnetic resonance imaging (MRI) which only provides structural information, uses magnetic fields and radio waves to examine the biochemical structure of tissues as well. The results? "There were definite brain chemical changes in the [athletes]," Dr. Lin said. 

Specifically, the findings showed in the athletes a 12.5% increased level of the chemical choline, a marker of tissue damage. Glutamate was also 12% higher, which in increased concentrations can cause cell death. Finally, the levels of gamma-aminobutyric acid (GABA), a neurotransmitter chemical involved in memory, was decreased by 8%. 

"[The findings tell] us that these guys with repetitive head injury do have something that is biochemically abnormal," Dr. Lin said. "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.” 

Glutamate, for example, is a neurotransmitter that is the major mediator of excitatory signals in the brain, meaning that it signals an “on” or “go” signal between two neurons. Glutamate also regulates functions such as making new connections between neurons, cell survival, and cell elimination (removal of neural connections that are no longer needed). If present in too high of a concentration, Glutamate can cause poor brain functioning. 

The findings are important because with tangible, scientific evidence of what is actually changing in the brain due to CTE, science may be able to begin focusing on treatments or medications that can alter the concentrations of these abnormal neurotransmitter levels. There are already medications that can alter the level of glutamate in the brain. The drugs amantidine and memantine are glutamate antagonists (a drug that blocks the activity of glutamate) that are sometimes used in the treatment of catatonic schizophrenia, a condition where there is an increase in brain glutamate activity. 

The authors concede that there needs to be more research into using this technique. Chris Nowinski, co-director of Boston University's Center for the Study of Traumatic Encephalopathy, remarked "With only five cases, we certainly can't draw any conclusions, but this takes us a step closer to identifying what the issue is." 

Dr. Lin is also hopeful. "As we grow the study we are convinced we will find a pattern unique to repetitive head injury.” 

"The hope is that someday, if this type of imaging technique can successfully identify CTE as it is happening, people like Mike Webster or Terry Long won't have to wait until their playing days are over and their lives are devastated by mental illness to realize that they have CTE. Medicine would be able to tell them that changes are occurring in their brains as they're happening, and the players can make the decision for their own health whether they should continue playing or not.

Review Date: 
December 2, 2010