Michael Jackson may be the only human ever to go two months without REM -- rapid eye movement -- sleep, which is vital to keep the brain and body alive.

"The symptoms that Mr. Jackson was exhibiting were consistent with what someone might expect to see of someone suffering from total sleep deprivation over a chronic period," Dr. Charles Czeisler testified at the wrongful-death trial.

Jackson could not do standard dances or remember words to songs he sang for decades at rehearsals, according to e-mails sent between show producers and choreographers. He became paranoid, was talking to himself and hearing voices, and experienced severe weight loss, Czeisler said. "I believe that that constellation of symptoms was more probably than not induced by total sleep deprivation over a chronic period."

If the singer had not died on June 25, 2009, of an overdose of the surgical anesthetic, the lack of REM sleep may have taken his life within days anyway, Czeisler said. Lab rats die after five weeks of getting no REM sleep. It was never tried on a human until Murray gave Jackson nightly propofol infusions for two months, he said.

Whitfield and Beard said that while they would have not been able to protect Jackson from Murray's treatments if they had been with him in Los Angeles, they might have been able to protect him from the troubles that robbed him of sleep.

"There was no one there just to step up and say he needed to rest," Whitfield said.

Murray served two years of a four-year jail sentence for involuntary manslaughter, while a jury in the civil wrongful death trial of concert promoter AEG Live decided he was competent to treat the singer.

The Jackson family

The world's first unshielded look at Michael Jackson's three children came at the televised memorial service on July 7, 2009. We saw Blanket, then 7, holding a doll of his father. Prince, 12, stood silently while Paris, 11, insisted on speaking about his father.

"Ever since I was born, daddy has been the best father you could ever imagine," Paris said, triggering a cascade of tears on faces around the world.

Paris, now 16, is living away from her two brothers at an undisclosed school, a move made after she cut her wrists in a suicide attempt a year ago.

Prince, a 17-year-old honors student at a private school in Los Angeles, and Blanket, a home-schooled 12-year-old, live with their grandmother Katherine Jackson, in a gated luxury neighborhood in Calabasas, California.

The family's relationship with the men named in Jackson's will as executors of his estate was rocky from the start, with both of the singer's parents challenging them for control in the first months after his death.

That turbulence is gone five years later, evidenced by a message posted on patriarch Joe Jackson's website last week: "I would like to thank the Estate of Michael Jackson for taking care of my wife Katherine and my grandchildren Prince, Paris and blanket."

The peace between Joe Jackson, 85, and the executors coincidentally -- or not -- came just as the estate purchased the home they had previously been renting for the family. Joe Jackson does not live there and is not a direct beneficiary of the estate.

Katherine Jackson, 84, remains active. She attended most days of the criminal trial of Conrad Murray and the civil trial of her lawsuit against the concert promoter AEG Live.

She is assisted in overseeing Michael Jackson's children by her grandson T.J. Jackson, who was appointed as a co-guardian after she went missing for several days during a bizarre family power struggle in July 2012.

Four of Michael's brothers -- Jackie, Tito, Jermaine and Marlon -- reunited onstage in recent years. The Jackson brothers recently completed a residency in Las Vegas and are touring the world, singing their Jackson 5 hits and some of the music Michael made without them.

Sister La Toya Jackson has built a reality TV career since her brother's death, appearing on Donald Trump's "Celebrity Apprentice" and her own "Life With La Toya."

Janet Jackson, one of the world's top selling recording artists, continues to work on music projects after her marriage to a Qatari billionaire announced last year.