Doctors 'optimistic' about Aussie BMX rider left in coma

Hopes are growing for severely-injured Australian BMX star Kai Sakakibara, even though he is yet to regain consciousness.

The 23-year-old remains in intensive care after last month's race crash left him with a severe head injury.

He was airlifted to hospital after crashing out of a World Cup round in Bathurst and needed surgery to relieve pressure on his brain.

While there is much uncertainty about Sakakibara's prognosis, his family said in a statement on Wednesday that there is cause for some optimism.

"A few weeks ago, doctors were not confident he would survive, but he has been fighting hard, and doctors are now more optimistic he will make it," they said.

"Kai has not woken up yet, so doctors don't have any real idea of the extent of the injury.

"However, they do know he had a severe knock to the head, and they tell us rehabilitation will take many many months.

"They also said that Kai is young and extremely fit, which will really help."

The immediate goal is for Sakakibara to come off his respirator as soon as possible so he can be moved out of intensive care.

More immediately, his family have put out a request for music to play to him in his hospital room.

As part of Sakakibara's treatment, the rap fan is being played music from the selection on his mobile phone and language is proving an issue.

"Some of the lyrics to the songs in his collection have a fair amount of explicit words beginning with the letter "f" or the word "mother"," his family said.

"The nurses like Kai's collection, they don't mind the lyrics and said that Kai has a great taste in music.

"However, it would be awesome if people could create some new playlists for #KaiFight77 on Spotify so we can play them for him."

Sakakibara injured in horror crash

Sakakibara fell on the second corner during his opening-round heat at a World Cup event in Bathurst and was treated on site by paramedics and a doctor before he was airlifted to hospital.

He began racing as a four-year-old, moving to Tokyo in 2000 and collecting multiple national titles before returning to Australia in 2008.

Sakakibara's parents Martin and Yuki said after the horrible incident that their son's BMX career was "on hold" as they focused on his long-term rehabilitation.

"We would like to thank everyone for the kind messages, prayers and thoughts regarding Kai," they said.

"It's amazing to know he has touched so many people."