Scottish rugby officials have put out an appeal to former international players to support a Glasgow University study into the long-term effects of concussion in the sport.

Over the past two seasons, a number of high-profile cases have provoked criticism of the immediate management of head injuries. However, concern has also grown around the possibility of players suffering from Chronic Traumatic Encephalopathy (CTE) a degenerative brain disease that leads to memory problems, personality swings and a general slowing-down of movement.

CTE does not usually become apparent until middle age, and can only be confirmed conclusively by post-mortem analysis. It has been suggested that rugby players could be particularly susceptible owing to the extremely physical - and possibly increasingly physical - nature of the game. CTE has already been identified in a number of individuals who previously engaged in contact sports.

However, the evidence to date is still patchy and largely anecdotal. Willie Stewart, a consultant neuropathologist at Glasgow Southern Hospital and a leading expert in the field, suggested more data was needed and former Test players could play a valuable role in the research.

"Recruitment is going well," said Dr Stewart of the early stages of the project. "However, the more former players who come forward to participate in the project, the better it will be for rugby union."

It is understood that players from the east side of Scotland had been more responsive than their counterparts in the west to appeals to get involved in the study, but the researchers are keen to get as many players involved as they can.

"We are pledged to make the game as safe as it can be within Scotland," said Dr James Robson, the SRU's chief medical officer. "Player welfare has improved considerably but that does not mean we can rest on our laurels."