SANTA CLARA A study of Joe Perry's brain found that the late 49ers running back suffered from chronic traumatic encephalopathy, an Alzheimer's-like disease linked to repeated brain trauma.
Dr. Robert Stern, co-director of the Center for the Study of Traumatic Encephalopathy at Boston University, said Perry's brain, like those of other athletes who have had CTE, showed a widespread presence of tau, an abnormal protein that over time replaces healthy brain tissue. At some point in the progression of the disease, there are no longer enough healthy brain cells and the brain stops functioning normally.
Perry's widow, Donna, said Perry began showing signs of dementia about 10 years ago.
She said Perry's friend Ollie Matson, an NFL running back who was a contemporary of Perry's, had a more advanced case than her husband, and it made her sensitive to the symptoms. Matson died in February at 80.
Perry's symptoms became progressively more prominent over the past decade. He died in April at 84.
"He'd get lost while driving," Donna Perry said Thursday. "And he'd call me on his cellphone and I'd tell him how to get home."
Stern said he could not release details of Perry's case because they will be part of an upcoming publication about CTE. Donna Perry, however, said she had a copy of the report, which said her husband's brain had atrophied another result of the disease and that it also had scar tissue from the pounding he absorbed and dished out when he played from 1948 to 1963.
On Sunday, Frank Gore passed Perry to become the 49ers' all-time rushing leader. Neither the 49ers nor the NFL, however, include the 1,345 yards Perry accumulated in 1948-49 when the 49ers were part of the All-American Football Conference. That league was partially absorbed by the NFL in 1950.
The brains of two other 49ers players who died this year also were donated to the Boston University study.
Running back John Henry Johnson, who along with Perry was featured in the 49ers' famed "Million Dollar Backfield" in the 1950s, died in June at 81.
Johnson's daughter Kathy Moppin said Thursday that the examination of her father's brain also showed that he had suffered from advanced CTE.
The brain of former 49ers center Forrest Blue, who died in July at 65, is being studied for signs of CTE. Blue, a four-time Pro Bowl player who ran a successful contracting business in Rocklin after his retirement, began showing signs of dementia in the mid-1990s. His daughter said she expected the results of her father's study next month.
Perry was inducted into the Pro Football Hall of Fame in 1969. Johnson was inducted in 1987. The families of other Hall of Famers, including Colts tight end John Mackey and Lions offensive lineman Lou Creekmur, also have donated the ex-players' brains to the study.
The Boston University study has found CTE in more than 20 former NFL players, including Dave Duerson, a one-time Chicago Bears safety who committed suicide in February by shooting himself in the chest so that his brain could be studied.
Stern said the center's research shows clearly that people who suffer from CTE have a history of repetitive brain trauma earlier in life, including from football, hockey, boxing or serving in the military.
But he said not everyone who has had repetitive brain trauma gets the disease, and a diagnosis can be made only posthumously. Stern, however, said he recently received a grant from the National Institutes of Health to study methods for diagnosing the disease earlier in a person's life.
Donna Perry said her husband and his cohorts all loved football and that Perry said on many occasions that even if he could do everything over again, he'd still play the game.
She said she's gotten the same question since her husband's death.
"People always ask me, 'Would you do away with football?' " Donna Perry said. "No, I enjoy football. I watch football. You're not going to stop football. But I don't know how you can make it better."