"In early morning hours of November 5 his heart stopped on two separate occasions requiring doctors to use an external pacemaker to regulate his heartbeat. He remains in critical condition, fighting pneumonia, a heart infection and irregular pulse," Jackson said. "The relatively positive prognosis which followed his previous surgery has dimmed."

According to CNN , authorities believe the actor fell asleep while driving and flipped his pickup truck several times before he was thrown from the vehicle through the windshield. The actor, who was last seen in 2011's "Walk a Mile in My Pradas," is said to have crushed several vertebra in his neck and back on impact.

"It is now believed that the hope of recovering upper body function was premature," Jackson added.

His mother previously wrote in a Facebook post that police said Marston was sober at the time of the crash, adding that he suffered multiple breaks and fractures to his neck, shoulder and ribs.

A GoFundMe page has since been created with all funds being "used to pay monthly bills as well as any unexpected expenses as they occur." As of Wednesday, the campaign raised more than $7,000.

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