Aaron Hernandez Had Brain Disease, Doctors Say

Former New England Patriots tight end Aaron Hernandez, who hanged himself last April in a prison cell, had a damaging brain disease linked with repeated concussions, doctors said Thursday.

Image: Aaron Hernandez Image: Aaron Hernandez

New England Patriots’ Aaron Hernandez kneels on the field during football practice in Foxborough, Mass., on May 29, 2013. Michael Dwyer / AP file

The examination by Dr. Ann McKee of Boston University School of Medicine showed Hernandez had chronic traumatic encephalopathy or CTE, which can cause loss of memory, impaired judgment and, sometimes, violent behavior.

“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),” Boston University Medical Center said in a statement.

Related: Judge Throws Out Hernandez Murder Conviction

“This diagnosis was confirmed by a second … neuropathologist. In addition, Mr. Hernandez had early brain atrophy and large perforations in the septum pellucidum, a central membrane.”

McKee’s research has shown the damage could explain seemingly inexplicable behavior, the university said.

Image: the classic features of CTE in the brain of Mr. Hernandez Image: the classic features of CTE in the brain of Mr. Hernandez

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. Ann McKee / Boston University CTE Center

“Her research has demonstrated that CTE is associated with aggressiveness, explosiveness, impulsivity, depression, memory loss and other cognitive changes,” it said in a statement.

Related: Hernandez’s Brain Held by Medical Examiner

Hernandez, just 27, was founded hanged in his cell in April. Friends and associates said he had shown no evidence of suicidal intentions but he was serving a life sentence for the 2013 murder of his friend, semipro football player Odin Lloyd. He had just been acquitted in another double slaying.

Just this summer, McKee’s team studied the brains of 202 former football players who had died. They found CTE in 177 of them. The NFL, however, has said little about the matter.

Boston University said it would have no further statement on its findings.