New scans may detect concussion’s long-term damage early

Here’s a mystery that parents, professional sports team owners and the nation’s top uniformed generals would all like to see solved: given a series of blows to the head, who is most likely to go on to suffer personality changes, depression, memory and concentration problems later in life?

Ideally, they’d want to know this early—perhaps before mom or dad signs junior up for tackle football or the Marines dispatch a newly minted jarhead to Afghanistan to face a plague of roadside bombs. Geneticists are already sifting through the genome for clues to that. Until they find those, however, it might be nice to know, once junior or the jarhead has already suffered a concussion or two, whether he or she should hang up the cleats or be posted to a quiet training base stateside.

Right now, the biological fingerprint of Chronic Traumatic Encephalopathy—a proposed name for the cluster of degenerative symptoms increasingly being identified in ex-athletes-- can’t be diagnosed until after death, when an autopsy can be done. There’s more and more reason to believe that the behavioral and cognitive problems of CTE can set in at an early age in those often hit--witness the recent finding that 21-year-old UPenn quarterback Owen Thomas, who committed suicide last April, already showed early signs of CTE. Waiting for old age--or a tragic death--to diagnose the problem is clearly not useful.

But that may be about to change.

At the annual meeting of the Radiological Society of North America this week in Chicago, Harvard Medical School researcher Alexander P. Lin outlined a new method to diagnose CTE—possibly in an early stage—in the living brain. The method uses a combination of magnetic resonance and radio waves to create a detailed image of the brain, including the stew of neurochemicals that must operate in perfect balance for the brain to function properly.

Lin and his colleagues used an imaging method known as magnetic resonance spectroscopy (MRS) to peer into the living brains of five former pro athletes with suspected CTE—a wrestler, a boxer and three football linebackers, each with a history of three to 15 known concussions. The imaging method revealed chemical profiles for the athletes’ jostled brains that were discernibly different than for those of the five healthy males of similar age and size they scanned for comparison. Lin and his colleagues noticed that the brains of subjects thought to be suffering from CTE had higher levels of neurotransmitters known as glutamate, GABA and aspartate than did the brains of healthy subjects. Disruptions in GABA and glutamate are also implicated in other several other brain diseases, such as Alzheimer’s disease and the inherited developmental disorder Fragile X.

Lin’s past work has looked at the brains of patients in a coma to glean their prognoses. He hopes that MRS scanning will also help predict which patients with milder forms of traumatic brain injury are likeliest to develop CTE so they can avert further damage and perhaps get early treatment.

Maybe, he added, if the MRS technique can help narrow down the list of chemicals that get scrambled in a brain damaged by repeated blows, researchers could zero in on drugs that could undo the damage that a career on the battlefield or the playing field has done.