Conan O'Brien jokes about concussion as he returns to 'Tonight Show'

Conan O'Brien turned his "Tonight Show" stunt injury into laughs at his expense by showing footage of the cringe-worthy backward fall on a hard studio floor.

"As many of you may know, on this past Friday's show I was doing a stunt and I hit my head and suffered a slight concussion. And I promise, if you're a good audience, I'll do it again tonight," O'Brien said during Monday's taping.

In a transcript released by NBC, he joked that he struck his head so hard "that for five seconds I actually understood the plot of `Lost.'"

O'Brien and guest Teri Hatcher were in a footrace when he slipped while trying to slide past the finish line, forcing Friday's show to be halted.

He played a clip of the fall and the studio audience gasped.

"I knew you'd hit your head. It looked like it was serious but then you called for a slo-mo," or slow motion replay, said his announcer, Andy Richter.

O'Brien looked like a rag doll as he picked himself up onto his knees and announced that Hatcher was the winner in a pained voice.

He said he didn't remember clearly what happened next, as he went to his dressing room to change into a suit for the next segment, an interview with Seth MacFarlane.

But back on stage he looked down at his blue cue cards and realized he didn't know what to do.

"It was like a menu for an Egyptian restaurant," O'Brien said.

His producer called him off the stage. O'Brien kept saying that he wanted to do the show, while his staff and a nurse quizzed him about what year it was, Richter said.

Richter accompanied him to the hospital, where doctors did a neurological evaluation.

"I really start to come back and I feel much better. And then one of the neurological questions was how many nickles in $1.35?" O'Brien said. "I've never known that!"

A "Tonight" rerun aired instead of the planned episode.

In his monologue Monday, O'Brien joked that he got so much media attention from the accident that he's planning a sequel with one of Hatcher's "Desperate Housewives" co-stars.

"So tune in tomorrow when Eva Longoria pushes me down an elevator shaft," the "Tonight" host quipped. "It's going to be sexy."

Before showing clips from Friday, O'Brien suggested parents "wake up your children because this is a cautionary tale."

The race between him and Hatcher was to end at the studio with the two rushing down stairs to the finish line. His memory was fuzzy, O'Brien said Monday, but he thinks he was trying to slide on a slick floor when he lost his footing.

"Why don't we show people what happened. Set your VCR to record, and your friends can all laugh watching this later," he said before the tape rolled. "`His pumpkin really got pounded' _ that's my father talking."

O'Brien took over as "Tonight" host in June, after Jay Leno's 17 years on the job. Leno is host of a new daily prime-time comedy show for NBC.