A study of Joe Perry's brain found that the former 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 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 that Perry's friend Ollie Matson, a running back who played at the same time as Perry, had a more advanced case than her husband, and it made her sensitive to the symptoms. Matson died in February at age 80.
Perry's symptoms became progressively more prominent over the last decade. He died in April at age 84. "He'd get lost while driving," Donna Perry said. "And he'd call me on his cell phone 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 was given a copy of the report, which said her husband's brain had atrophied - another result of the disease - and also had scar tissue from the pounding he absorbed and dished out when he played from 1948-1963.
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 and '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 several other 49ers players who have died in recent years also have been donated to the Boston University study. That includes John Henry Johnson, who along with Perry was featured in the 49ers' famed "Million Dollar Backfield" in the 1950s. Johnson died in June at age 81. Johnson' daughter, Kathy Moppin, said Thursday that the examination of her father's brain also showed that he had been suffering from advanced CTE.
The brain of former 49ers center Forrest Blue, who died in July at age 65, also is being studied for signs of CTE. Blue, a four-time pro bowl player who ran a successful contracting business out of 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.
The 49ers are wearing decals with Perry's No. 34 and Johnson's No. 35 on the back of their helmets this season.
-- Matt Barrows