Spokesperson: NFL will ‘vigorously’ fight claims in Hernandez lawsuit

Former New England Patriots tight end Aaron Hernandez turns to look in the direction of the jury as he reacts to his double murder acquittal at Suffolk Superior Court Friday, April 14, 2017, in Boston. (AP Photo/Stephan Savoia, Pool)

CHICAGO (AP/WPRI) — A spokesperson for the NFL said Friday the league would fight claims that it was to blame for repeated head trauma that caused the brain disorder CTE in the late Aaron Hernandez.

The lawsuit, filed Thursday on behalf of Hernandez’s daughter, claims CTE led to him taking his own life behind bars. Hernandez was serving a life sentence for murder and had just been acquitted of two other murders before committing suicide.

Hernandez’s brain was riddled with damage from a degenerative brain disease linked with head blows, but that doesn’t necessarily explain the troubles that plagued his young life.

The diagnosis comes from a Boston University researcher who has studied hundreds of brains from football players, college athletes and even younger players, donated after their deaths. Dr. Ann McKee announced Thursday she found evidence of severe chronic traumatic encephalopathy, or CTE, in Hernandez’ brain. Her autopsy also found signs of early brain shrinkage even though Hernandez was only 27 when he hung himself in prison in April.

View a scan of Hernandez’s brain from BU »

His lawyer filed a lawsuit against the NFL and the New England Patriots on Thursday, claiming they failed to protect their players’ safety.

What’s known about CTE and how it affects the brain:

DOES CTE MAKE PEOPLE VIOLENT?

CTE can affect areas of the brain involved with regulating behavior and emotions. Aggression, depression, memory loss and dementia are among symptoms in former football players whose brains were donated to research, and some died by suicide. But substance abuse and other illnesses may be linked with those symptoms and there is no proof that CTE-related brain damage causes those behaviors.

Hernandez was serving a life sentence for a 2013 murder when he died, and had been acquitted in two other killings. An associate had earlier accused Hernandez of shooting him in the face after an argument at a strip club. Hernandez’ background included other aggressive behavior and drug use.

WHAT CAUSES CTE?

Repeated head blows from contact sports and military combat are the most likely causes, scientists say. These hits can cause the brain to ricochet inside the skull, damaging nerve cells. Researchers are seeking to identify genes that may make certain people susceptible to damage from head blows, and they believe drugs and alcohol might also play a role.

CTE can only be diagnosed after death. A defining feature is abnormal deposits of tau, a protein that occurs naturally in the brain but is displaced in CTE. Tau build-up can damage or destroy brain cells.

HOW COMMON IS CTE?

In an account published in July, McKee reported finding CTE in the brains of all but one of 111 ex-NFL players studied. Most donated brains from former college players studied also showed signs, as did 20 percent of donated brains from high school players, most of whom died by suicide or drug overdoses.

But experts say most people recover from repeated head blows and the true frequency of CTE in football, other sports, the military and the general population is not known. It is not known how many head hits Hernandez experienced; he was a star in high school and college football and played most of three seasons with the New England Patriots. He was released in 2013 after his arrest.

WASN’T HERNANDEZ TOO YOUNG TO HAVE CTE?

Most brains donated for research are from older players but McKee has found CTE in an 18-year-old and her recent study found evidence of the disease in three high school players.

Below is the full statement from Boston University released on Thursday:

“A neuropathological examination of Aaron Hernandez’s brain was conducted by Dr. Ann McKee, Professor of Pathology and Neurology at Boston University School of Medicine, Director of BU’s CTE Center and Chief of Neuropathology at the VA-BU-CLF Brain Bank.

“Based on characteristic neuropathological findings, Dr. McKee concluded that Mr. Hernandez had chronic traumatic encephalopathy (CTE), Stage 3 out of 4, (Stage 4 being the most severe). This diagnosis was confirmed by a second VABHS neuropathologist. In addition, Mr. Hernandez had early brain atrophy and large perforations in the septum pellucidum, a central membrane.

‘”This graphic shows the classic features of CTE in the brain of Mr. Hernandez. There is severe deposition of tau protein in the frontal lobes of the brain (top row). The bottom row shows microscopic deposition of tau protein in nerve cells around small blood vessels, a unique feature of CTE.

“Dr. McKee and the BU CTE team have extensive experience in the diagnosis of CTE and have contributed landmark publications on traumatic brain injury and CTE in athletes and Veterans. Her research has demonstrated that CTE is associated with aggressiveness, explosiveness, impulsivity, depression, memory loss and other cognitive changes.

“We are grateful to the family of Aaron Hernandez for donating his brain to the VA-BU-CLF brain bank, located at the Jamaica Plain campus of the VA Boston Healthcare System.”