The family of Pro Football Hall of Famer Frank Gifford says signs of the degenerative disease chronic traumatic encephalopathy were found in his brain after his death.

In a statement released through NBC News on Wednesday, the family says Gifford suffered from unspecified "cognitive and behavioral symptoms" in his later years. He died of natural causes at his Connecticut home in August at age 84.

His widow, Kathie Lee Gifford, is a host for NBC's "Today."

The statement says that the family "made the difficult decision to have his brain studied in hopes of contributing to the advancement of medical research concerning the link between football and traumatic brain injury."

CTE can be diagnosed only after death. It has been found in the brains of dozens of former players.