LOS ANGELES (Reuters) - Doctors treating rocker Bret Michaels for a brain hemorrhage are hopeful he will make a full recovery, but regaining his health will be painful and could take weeks or months, the singer's publicist said on Tuesday.

Doctors said the Poison front man and "Celebrity Apprentice" TV contestant was lucky to have escaped death from the brain hemorrhage last week, and he is now in "positive spirits."

However, tests on Michaels, 47, revealed a potentially worrying side effect from the brain hemorrhage that could cause future seizures. So far, he has had no such seizures.

"Doctors state Michaels is very lucky as his condition could have been fatal. With further testing and rehabilitation, they are hopeful that Bret will gradually improve as the blood surrounding the brain dissolves and is reabsorbed into his system, which can be a very painful recovery and take several weeks to months," Tuesday's statement said.

"Michaels remains under 24-hour observation in the intensive care unit and is in positive spirits. He is responding well to tests and treatments...Doctors remain hopeful for a full recovery," it added.

Michaels, reported to be in an Arizona hospital, was described on Sunday as suffering from slurred speech and blurred vision.

His father, Wally Sychak, told celebrity news site Extra on Tuesday that he had spoken with his son by phone. "He sounded a little slow, but fine. He was talking, not as cheerful as he usually is. But I guess he is under sedation," Extra quoted Sychak as saying.

Messages of support from Michaels' celebrity friends and fans have flooded in, causing his official web site to crash or slow under the traffic.

"Your heart goes out to his family, your heart goes out to him. He's the nicest guy in the world," Sharon Osbourne, wife of British rocker Ozzy Osbourne and a contestant with Michaels on "Celebrity Apprentice" told celebrity magazine Us Weekly.

Michaels found fame in the 1980s at the helm of rock band Poison, whose hits include "Every Rose Has Its Thorn."

He later appeared in VH1's dating contest "Rock of Love" and on the current season of "The Celebrity Apprentice", which was filmed several months ago but is about halfway through its broadcast run on NBC.

Michaels was diagnosed with diabetes as a child and two weeks ago he had an emergency appendectomy, which he described afterward as a "wake-up call to be a little bit more diligent on keeping control of my health."