Could a “living” diagnosis of a brain disorder affect the outcome of a trial?
In the case of former NFL player Aaron Hernandez, experts think it might have.
In 2015, the former tight end for the New England Patriots was convicted of murder.
Two years later, Hernandez died by suicide days after being acquitted in a second homicide case.
After his death, Hernandez was found to have signs of chronic traumatic encephalopathy (CTE) in his brain tissue.
Jose Baez, the attorney for Hernandez’s family, said the former player’s CTE was “the most severe case they had ever seen in someone of Aaron’s age,” according to ESPN.
Is CTE a defense?
CTE is a degenerative disease known to cause a variety of side effects, including aggression, impulse control, and suicidality.
There’s no cure for the disease. It can only be diagnosed posthumously with brain tissue.
In the wake of Hernandez’s diagnosis, some have wondered if a definitive diagnosis during his lifetime would’ve made a difference.
A person with the disease may be at more risk for aggression. But it’s still impossible to know if it’s the person or disease responsible in the case of a murder or suicide.
Amy Dillard, an associate professor of law at the University of Baltimore School of Law, said that a CTE diagnosis could’ve affected Hernandez’s trial.
In an opinion column published in The New York Times, Dillard and another law professor at Drexel University’s Thomas R. Kline School of Law wrote that a recent study finding that 110 of 111 brains from NFL players had signs of CTE could be enough evidence to convince a jury of reasonable doubt.
Dillard told Healthline that with more information about CTE and its link to impulse control and aggression, a lawyer could make a case that Hernandez’s condition affected his “criminal intent.”
Dillard pointed out that in Massachusetts, prosecutors have to prove criminal responsibility beyond a reasonable doubt.
If a person has a disorder that affects their ability to develop criminal intent, that can lead a jury to decide if a person is not guilty by reason of insanity.
“I might say [in court], ‘I’ve given you some scientific evidence about my client, he had these symptoms,’” Dillard said.
She explained she could then tell the jury they’d have to look at the evidence of head injury and decide if it affected a defendant’s ability to “form criminal intent” and “to control his impulse to know what he was doing was right or wrong in that moment.”
She pointed out that even without a specific test that could definitively “prove” a player had CTE before their death, in a court of law, the attorneys could bring up the possibility of the disorder as a reason to cast “reasonable doubt.”
“The lawyer’s job is often to take those sorts of pillars of knowledge and connect them together so that the jury might understand,” she said.
A new test on the horizon?
Doctors have had difficulty giving people even a suspected diagnosis of CTE because the symptoms can be caused by a variety of other conditions.
Researchers from the CTE Center at Boston University School of Medicine concluded that a protein called CCL11 could be a biomarker that indicates a person has CTE.
The team tested brain tissue and cerebrospinal fluid of 23 deceased NFL players with CTE, as well as 50 people who had Alzheimer’s disease and 11 people who had neither condition.
They found that the players with CTE were far more likely to have this kind of protein in the spinal fluid and brain.
However, it’ll take more time and a much larger pool of data before that test could be considered effective for a CTE diagnosis.
Why doctors can’t diagnose CTE before death
Today, medical experts say that despite the known risks for football players and other athletes with head injuries, it’s still impossible to definitively tell someone they have CTE.
Dr. Michael De Georgia, director of the Neurocritical Care Center at UH Cleveland Medical Center,said despite advances, doctors still can’t definitively diagnose a person with CTE until they’ve examined their brain posthumously.
“There was a case [of] Todd Ewen,” De Georgia recalled. “He’d been playing hockey his entire life and he also developed cognitive problems.”
Ewen developed “memory loss, chronic body pain, diabetes and undiagnosed depression,” according to a report released by the Krembil Neuroscience Centre’s Canadian Concussion Centre.
Ewen eventually died by suicide in 2016. However, doctors found no sign of CTE when they examined his brain.
“We were very surprised by the results, as we were sure Todd must have had CTE,” Kelli Ewen said in a statement about her husband released by the concussion center. “We hope that anyone suffering from the effects of concussion takes heart that their symptoms are not an automatic diagnosis of CTE. Depression coupled with other disorders can have many of the same symptoms as CTE.”
De Georgia said doctors have learned much more about CTE in recent years. He pointed out they now classify the disease into four stages, which can help them treat patients:
- Stage 1. The earliest stage can lead to headaches, difficulty paying attention, short-term memory problems, among other symptoms, according to a published report by Boston University.
- Stage 2. This stage can build on the previous symptoms with “depression, explosivity, and short-term memory loss.”
- Stage 3. In this stage, a patient may start to also exhibit cognitive dysfunction and executive impairment.
- Stage 4. During this final stage, patients may have “dementia, word-finding difficulty, and aggression,” according to the report.
De Georgia said doctors try to rule out other causes of these symptoms so that the patients can get the best care possible.
But without a better method of testing, he said they can’t definitively tell people whether or not they have CTE and what their symptoms will be in the future.
“Certainly, if your patient is a professional football player with a history of multiple concussions, you’d be attuned to CTE,” he said. “But that’s not always the case. It’s very difficult to tease out.”