Bret Michaels remains in a critical but stable condition
Poison singer Bret Michaels is in "positive spirits", despite being diagnosed with a side effect relating to the recent haemorrhage he suffered.
A statement on his website said test results had shown his body currently has a lack of sodium which could lead to seizures.
"Even though today was a minor setback, doctors remain hopeful for a full recovery," the statement added.
The 47-year-old remains under observation in hospital in Los Angeles.
He was admitted last Friday with a severe headache.
Michaels, currently being seen on US TV on Celebrity Apprentice, was found to have suffered a subarachnoid haemorrhage, or bleeding onto the surface of the brain.
He remains in a critical but stable condition, his website said.
The statement added: "They [doctors] 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."
The star very recently had his appendix removed in an emergency operation and also has diabetes.
Poison had hits including Every Rose Has Its Thorn and Unskinny Bop and Michaels recently recorded a song with teenage star Miley Cyrus.
Speaking on US chat show Larry King Live, Donald Trump Jr - who worked with Michaels on Celebrity Apprentice - called him a " likable guy, down to earth and a solid person."