It has been a bad week for the image of elite rugby: George North continuing to play for Wales in what appeared to be a concussed condition, and a Rugby Football Union injury audit which confirmed concussion (the most common injury) was up for the third consecutive year, by 59 per cent.

The RFU audit covered the English professional game during 2013-14 and cited an increase from 54 cases to 86 - 10.5 concussions per 1000 hours played. Glasgow neuropathologist Dr Willie Stewart branded this "totally unacceptable" and, in an exclusive Herald Sport interview, called for intervention to prevent "young men being damaged beyond repair".

Given that Dr Stewart is on World Rugby's four-strong independent concussion advisory panel, his assessment is disturbing, especially so given that he rejects the view of RFU chief medical officer Dr Simon Kemp that the 59 per cent increase is due to greater player awareness of symptoms and better medical diagnosis and recognition.

"The underlying trend over more than 10 years has been a year-on-year increase in concussion," said Dr Stewart. "In my opinion this does not relate at all to recognition. It's to do with an increasing injury rate. Yes, this year's figure increased exceptionally because of better recognition, but that doesn't justify young men sustaining brain injury at the rate of more than 10 per 1000 hours. These are real injuries. In last weekend's Six Nations it was almost double the RFU Premier League audit figure. Brain injury in rugby, in my opinion, is at an unacceptably high level.

"There is considerable under-reporting. For every single concussion that is appreciated, another four or five are not picked up on . . . We are still only half way towards the real figure which I think is near what we saw last weekend, getting towards 20 concussions per 1000 hours.

"At that point the chance of injury in elite rugby is certainly as high as in boxing [17 per 1000 hours] but a rugby career goes on much longer than most boxers, and exposure is much higher, with 30-odd 80-minute matches a year.

"If George North had been a boxer last Friday, he would not be playing again until late March. Yet they talked about bringing him back this weekend. Rugby can no longer say this is just a quirk, because we are recording these injuries more. We can't walk away and forget about it, despite doing great things to educate people.

"Rugby has to do something to reduce the level of injuries, particularly concussion. It's unacceptable in senior professional rugby. Young men are being damaged beyond repair. George North should have been off, and heading for the neurosurgery unit."

Contradicting the RFU assertion that severity of injuries is unchanged, Dr Stewart adds: "When the audit started, time-out after injury was two weeks. Now we are heading for four weeks per injury.

"I don't think rugby would lose anything by modifying the rules. It needs to do something or it will lose badly. It's happened in the NFL, and in boxing decades ago - parents and people turning away because it's just not worth the risk."

Yet if rugby protocols are short of perfect, they surpass those of most other sports. Dr Stewart, once a prop with Cambuslang, has been campaigning on such injuries for years and says rugby has done what other sports have yet to do. He, Robert Cantu (USA), Jon Patricios (South Africa), and Caroline Finch (Australia) are independent consultants and comprise a four-strong advisory group appointed more than a year ago by World Rugby. They tackled the issue at four levels, from the grass roots up, establishing sound and safe guidelines on how concussion should be managed. These have been highly praised and adopted and adapted by other sports whose guidelines were inconsistent.

"The world body has done a good job in terms of improving practice, adopting pretty much everything we suggested - concussion management across the global game from grass roots up. We were not neglecting the professional game, but thought 99.9 per cent was worth fixing first."

Their first meeting on the elite level was last Monday - simply coincidence, arranged long before the North incident which Dr Stewart describes as "watching years of messaging unravelling before our eyes. It shows just how far we have to go. The overall reaction has probably saved long-term damage, but we need the elite to demonstrate safe practice. We all agreed George North should have been removed.

"We have recommended video be reviewed live, and a strengthening of the TV match official's role. Scottish rugby has been doing this since 2009, after a similar incident with Simon Webster when he was knocked out against Wales.

"I understand Wales will also use live video review on Sunday, which may be the first time for both sides in the Six Nations. I will be surprised if that's not soon the norm for all Six Nations matches."