Aldon Smith's family donates brain for CTE research after sudden death

The family of former NFL star Aldon Smith has donated his brain to Boston University's CTE Center for research into the effects of repetitive head trauma, following his sudden death at age 36 on Saturday.

Smith was found unresponsive in his truck hours after delivering pizzas to a homeless charity in the San Francisco Bay area. No cause of death has been announced. Pastor Scott Wagers, who interacted with Smith on Saturday, told media outlets the former player seemed tired but was otherwise gentle and friendly during their time together.

Smith's family has hired attorneys Harry Daniels, Bakari Sellers and Wayne Kendall to investigate the circumstances surrounding his death. The legal team is conducting a comprehensive investigation that includes having Smith's brain examined for damage caused by concussions and other trauma.

Smith entered the NFL in 2011 as a first-round pick and emerged as a dominant defensive force during his career with the San Francisco 49ers. His professional trajectory was marked by off-field incidents and multiple suspensions that overshadowed his on-field performance.

Chronic traumatic encephalopathy, or CTE, is a degenerative brain disease linked to repetitive head trauma. The condition can only be diagnosed after death and has been associated with depression, impulsive behavior, memory loss, mood disorders and severe personality changes.

Several former NFL players have been found to have suffered from CTE following their deaths. Hall of Fame linebacker Junior Seau, who died in 2012, was later found by researchers to have suffered from advanced CTE. Family members described dramatic personality changes, depression, emotional withdrawal and sleep issues during the period before his death.

The San Francisco 49ers released a statement following Smith's death, saying "His smile lit up every room."