An emotional Dr Brukner said the 25-year-old suffered an "incredibly rare" vertebral artery dissection caused when a cricket ball struck his neck during a Sheffield Shield match in Sydney on Tuesday. 

The blow caused Hughes' vertebral artery, one of the main arteries leading to the brain, to compress. That caused the artery to split and Hughes experienced a "massive bleed into his brain". 

"I think in this instance, this was a freakish accident because it was an injury to the neck that caused a haemorrhage in the brain," Dr Brukner said.

"The condition is incredibly rare. It's called vertebral artery dissection leading to subarachnoid haemorrhage, if you look in the literature there are only about 100 cases ever reported."

The injury is often immediately fatal, Dr Brukner said, however Hughes was resuscitated on the pitch and was transported to St Vincent's Hospital.

"He was not in pain before he passed and was surrounded by his family and close friends," Dr Brukner said. 

The head of trauma at St Vincent's Hospital, Doctor Tony Grabs, also described Hughes' injury as "very rare, very freakish", saying such a condition had never been treated at the hospital before. 

Dr Grabs said Hughes' injury was "catastrophic" and after an immediate scan to assess his injuries, doctors decided they needed surgery to relieve the pressure on his brain.

"What sometimes happens in the brain is if you put blood around the brain, a small amount, you will start to become a bit drowsy. If you put a lot of blood around the brain you will become unconscious.

"He went to theatre and had extensive surgery to remove some of the skull around the brain to help allow the brain to expand so it wasn't compressed."

The surgery took about one hour and 20 minutes. Hughes was then placed in an induced coma in intensive care so he could recover but over the next 48 hours "did not make very much improvement".

When asked about the ambulance response, both doctors praised the treatment Hughes received on the field and said he arrived at hospital in a good condition. 

It took paramedics 15 minutes to reach Hughes at the Sydney Cricket Ground and two triple-0 calls were made. 

Dr Brukner said ambulance waiting times are only relevant when the injured patient is not being treated and that by "any standard and observation he was receiving excellent quality treatment on the pitch".  

Before paramedics arrived, NSW team doctor John Orchard and Dr Tim Stanley, an intensive care specialist who was in the stands, treated Hughes. 

Dr Brukner also paid tribute to the team that treated Hughes at St Vincent's. 

"They have done a magnificent job and given magnificent support to the family and friends of Phillip," he said.

"Full credit to this amazing institution."

Sean Abbott, the NSW cricketer who delivered the ball that struck Hughes, visited the hospital and spoke with both Australian team captain Michael Clarke and Hughes' sister Megan, Dr Brukner said.

"Obviously what Sean's gone through is an incredibly traumatic experience, as it has been for everyone who was present on the field on that day, and Sean is receiving all possible support from Cricket NSW and Cricket Australia," he said.

Cricket Australia boss James Sutherland said helmets are continuously upgraded and reviewed, but right now the organisation was focused on providing support to Hughes' family and friends. 

"It's important to realise that yes we certainly need to review all our procedures and equipment but this is an incredibly rare type of injury," Dr Brukner added.

Michael Clarke has endured a lot in his stellar career, but his bleary eyes suggested nothing has ever rocked him like it did on Thursday afternoon. 

The Australian captain arrived to a press conference just over an hour after his Australian, New South Wales and Western Suburbs teammate had passed away in unthinkable circumstances.

By the side of his wife Kyly, who looked equally as deflated, Clarke's flannelette shirt and tracksuit pants painted a harrowing picture of a man devastated to his absolute core. 

Without any more tears to give, Clarke valiantly read out a statement from Hughes' family. Understandably, he is yet to find his own words, much like the entire cricketing world on the darkest day in the sport's history. 

The press conference ran nine minutes late because of an apparent problem with a speaker. It's more plausible Clarke was having difficulty speaking at all, fresh with the news no one ever wanted to hear. 

Cricket Australia boss James Sutherland followed Clarke at the press conference: he fought back tears when reminiscing about the precocious talents of a teenage Hughes making his mark on the domestic and international scene with a flurry of cut shots and crisp straight drives. 

Team doctor Peter Brukner's bottom lip quivered numerous times, having witnessed firsthand the terrible injury Hughes sustained, doing what made him happier than anything else - scoring runs on the cricket pitch.  

An exhausted Pat Howard, the Australian high performance manager, slumped in his seat, head in his hands and struggling to comprehend how, and more importantly, why. 

There will never be a more sombre mood than that overcast Thursday afternoon. 

Accidents happen, and there are certain to be more of them, but such an accident which has taken the life of an exuberant young man has hurt people in a way they didn't think possible. 

Journalists' eyes watered, many of whom have known Hughes for years. He was this reporter's first 'big' interview and has been commended by all who knew him for his humble and accommodating nature with the press. 

Privacy has been asked for and it must be respected. A funeral and public gathering to pay respects to Hughes have not been formally arranged. 

As for Clarke, the man who loved Hughes as much as anyone, he has scaled the heights of world cricket.

He has conquered England, South Africa, almost every bowler in world cricket, but in times like these, cricket fades into a black hole of oblivion and worthlessness. 

smh.com.au