On the same week that he appeared on "The Oprah Winfrey Show" to discuss his hospitalization for a brain hemorrhage, Bret Michaels was readmitted to a hospital after suffering a "warning stroke."

According to the Poison frontman's official Web site, Michaels suffered a Transient Ischemic Attack (TIA) or warning stroke. The "Celebrity Apprentice" finalist was suffering numbness on the left side of his body, according to a note posted on his site Thursday.

His symptoms led to a hospital visit and subsequent tests which revealed that he suffers from Patent Foramen Ovale -- having a hole in his heart.

According to Michaels' site, the rocker's neurosurgeon believes that the heart condition is treatable and operable, and that it could have been the reason why Michaels had the "warning stroke." The condition is believed not to be related to his brain hemorrhage.

Dr. Zabramski is quoted on Michaels' site as saying, "I realize Bret wants to make a full recovery so that he can be active with his family, attempt to attend the finale of 'Celebrity Apprentice' and especially, get back on the road to continue making music. Without a doubt he is very determined to get healthy and make a 100 percent recovery. Medically speaking it is a fantastic attitude both mentally and physically for him to have. However, Bret's brain and body are not quite 100 percent yet, especially with the hole found in his heart. Further tests will be conducted throughout the week and I will have more information next week as to how this Patent Foramen Ovale (PFO) will be treated. For now, Bret will be treated with outpatient care which includes a daily injection of Lovenox (a blood thinner to reduce the chance of blood clots) and blood tests."

A rep for Michaels wrote, "Bret wants everyone to know he cannot thank you enough for all of the well wishes, prayers, and good vibes you have sent his way. Even though these last few months have been tough on him and his family, especially this most recent setback, he is in good spirits, great medical hands and is positive and hopeful that everything is going to be OK. He is up, walking, talking, continuing his daily rehab and very happy to be alive but he has made it clear he is sick and tired of being in the hospital and is ready to rock again."

Related stories: Bret Michaels Announces Concert Comeback, Eyes Return to 'Celebrity Apprentice' 

 Bret Michaels: I Knew Something was 'Severely Wrong'