Bret Michaels is back in the hospital.

The rocker and reality TV star suffered what doctors call a "warning stroke" and has been diagnosed with a patent forum ovale, or hole in the heart, according to a report Thursday (May 20) on his website. Michaels' publicist, Joann Mignano, confirmed the report.

Michaels was hospitalized after experiencing numbness on the left side of his body, particularly in his face and hands.

Doctors said the condition is operable and treatable and likely unrelated to the brain hemorrhage the 47-year-old suffered last month.

Michaels' neurosurgeon said that while the Poison frontman has a "fantastic attitude" about making a full recovery, "Bret's brain and body are not quite 100 percent yet, especially with the hole found in his heart."

Additional tests were being conducted to determine the best course of treatment. Doctors said Michaels is currently being treated with a daily injection of a blood thinner to reduce the risk of clots.

His website said Michaels was "up, walking, talking, continuing his daily rehab and very happy to be alive."

"He has made it clear he is sick and tired of being in the hospital and is ready to rock again," the site says.

Michaels was expected to appear at Sunday's finale of Donald Trump's "The Celebrity Apprentice" in New York. NBC said in a statement that the network is "cautiously optimistic" that Michaels can attend the live season finale.

"Ultimately, it's up to Bret and his doctors if he should attend," the statement said.

In the episode, Trump's boardroom revelation of the winner will air live. The rest of the show was taped last year, including the final challenge segment.

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