"ETC," what is this chronic disease of American football at the heart of a shooting in New York?

An illness that gnaws silently, to the point of madness. On Monday evening, in a Manhattan skyscraper, Shane Tamura opened fire, killing four people, before turning the weapon on himself. According to local authorities, the 27-year-old targeted the National Football League (NFL), convinced he suffered from chronic traumatic encephalopathy (CTE), a condition he associates with playing American football in high school. "Study my brain, I'm sorry," he wrote in a note tucked into his wallet, revealed Tuesday, July 29.

This brain condition, which has already disrupted the lives of many American football players, is at the heart of several scandals that have rocked the NFL. It is a neurodegenerative disease caused by repeated head trauma, including impacts that do not cause concussions. Its effects can appear several years after the cessation of exposure to impacts, often around the age of thirty.

The symptoms are as multiple as they are destructive: depression, anxiety, memory loss, insomnia, impulsiveness, hallucinations, aggression, suicidal thoughts... On the physical side, victims describe chronic headaches , dizziness, sensory hypersensitivity and even motor disorders.

Known since the 1920s as dementia pugilistica in boxers, CTE was recognized in 2002 thanks to Dr. Bennet Omalu. This Nigerian forensic pathologist discovered unusual brain degeneration while autopsying the brain of Mike Webster, a former star of the American football club Pittsburgh Steelers, who died at the age of 50. He observed an abnormal accumulation of tau proteins in the brain tissue, which would have led to the progressive destruction of nerve cells. A process that strangely resembles that of Alzheimer's disease . He then named this disease and finally gave it a scientific definition.

ETC has become a topic of research and controversy that regularly makes headlines. So much so that a film adaptation starring Will Smith , The One Against All, was released in theaters in 2015.

The Webster case would pave the way for a series of damning revelations. In 2017, a study conducted by Boston University's UNITE Brain Bank—a brain bank dedicated to researching traumatic brain injuries—showed that of the 111 former NFL players autopsied, 110 had CTE. By 2023, this figure had risen to 345 cases out of 376 brains analyzed, or more than 90% of cases.

Faced with mounting pressure, the NFL responded. In 2013, it reached an out-of-court settlement with 4,500 former American football players, for a total of $765 million, to resolve thousands of claims. But this arrangement was heavily criticized. To expect compensation, players must provide an MRI showing a decline in their cognitive abilities. However, until 2021, the federation relied on the controversial method of race-norming , which was based on the unfounded idea that African Americans have, on average, inferior cognitive functions than whites. This bias significantly reduced their chances of demonstrating abnormal cognitive decline, and therefore of being compensated. Faced with outrage, the NFL eventually abandoned this practice.

To date, no test can formally diagnose the disease in a living patient. Only a post-mortem autopsy can confirm CTE. However, research programs are exploring promising avenues, such as positron emission tomography imaging. In 2019, researchers successfully differentiated CTE-specific tau proteins from those of Alzheimer's, opening a possible avenue for ante-mortem diagnosis.

In the absence of a cure, treatment for CTE relies on symptom management. Typically, doctors prescribe antidepressants , anti-anxiety medications, or medications for Alzheimer's disease. However, these treatments do not slow the progression of the disease and can cause severe side effects.

The only truly effective response remains the prevention of these repeated collisions. However, CTE affects all contact sports. Rugby, ice hockey, boxing, baseball, martial arts... Even football is affected. In the United Kingdom, a study estimated that a professional football player could head more than 10,000 times during their entire career. This statistic led the federation to ban the practice for children under 12.

In France, Raphaël Varane, former defender for Les Bleus, called in 2024 in L'Équipe for a rethinking of this practice. In April, Sébastien Chabal, an iconic figure in French rugby, also sounded the alarm about the consequences of head impacts , claiming to have "no memory of a single match" from his career. Like many international athletes in recent years, the two Frenchmen joined the call of their peers, calling for more scientific research and a change in practices in the sporting world.