Mr Meldrum said his brother was likely to remain sedated until early next week.
"With bruising, that will get probably worse before it gets better, so they need him under sedation until that happens,'' he told reporters outside the hospital on Friday afternoon.
"At the moment there's little steps forward, but there's nothing to say that things couldn't go backwards, so in that respect he's not out of danger as far as his life goes.
"But at the moment things are progressing along the way they (doctors) want it to go. It's only minute, but it's going the right way.''
The Alfred's director of neurosurgery, Jeffrey Rosenfeld, said it was too early to predict the chances of a full recovery.
"We're really concerned for his life; it's a life-and-death matter,'' Dr Rosenfeld said.
Music industry figures, including Kylie Minogue and Boy George, actors and fans took to social media sites with messages of support.
Prime Minister Julia Gillard also joined the well-wishers.
- AAP
