Wales rugby star Jonathan Thomas quits rugby due to epilepsy
The leading epilepsy research charity said that while many international sportsmen with epilepsy were able to continue in their chosen sport, it was important that individuals did what was right for them.
Professor Ley Sander, medical director at Epilepsy Society said: 'Epilepsy is a very individual condition affecting people in different ways. Rugby is a very physical, contact sport and the rugby field can be a very unforgiving environment. There are many sportsmen and women who have epilepsy yet are able to continue with their career, obviously making appropriate risk assessments.
'Jonathan Thomas has followed exactly the right course by taking medical advice and looking at what is right for him after sustaining a brain injury and being diagnosed with epilepsy.'
In a statement, Jonathan's club Worcester said that he was diagnosed with epilepsy last year which is thought to be from multiple head traumas and a degree of brain injury.
Jonathan, who won 67 Wales caps between 2003 and 2011 and played in two World Cups, has now stepped down on medical advice.
Head injuries and sport
News of his retirement comes as the World Cup prepares to kick off later this week, and delivers another stark reminder of the debate around head impacts and concussion which has dominated rugby union's agenda in recent months.
Worcester high performance director Nick Johnston said: 'We've sought the best medical opinion in the country in order to try and enable Jonathan to prolong his career.
'But unfortunately, on the advice of consultants, he has been advised to retire from professional rugby.'
Talking about his decision, Jonathan said: 'It's with real sadness I have to announce my retirement from the game with immediate effect.
'I was diagnosed with epilepsy last season, which is thought to be from multiple head traumas and has led to a degree of brain injury.
'I've done everything in my power to keep playing. However, there comes a point when you realise you need to listen to medical experts and also do what's best for your well-being.
Many types of epilepsy
'I am keen to stress there are many different types of epilepsy, and I'm fortunate to only suffer from it in a mild way compared to some. Naturally though, it has proved too difficult to continue as a professional athlete.
'I have been working closely with my medical team and consultant for many months, and hoped this was something that could be managed in order for me to continue playing, but sadly this isn't the case.
'I am extremely grateful to the Warriors medical staff and management for all the support they have given me during this time."
Thomas added that he intends to be remain involved with rugby.
'In regards to the immediate future, I'm going to take some time out but have no doubt I'll stay involved with the game in some capacity.
'I would also like to get involved with charity work specifically related to head injury and help people gain a better understanding of what trauma can cause and how to deal with it.
'I've learnt a huge amount during the last few months about head trauma, seizures and epilepsy, and it would be great if I could help out in some way.
'At the elite level of the game, I think the unions and medical departments of clubs do a great job and have a great understanding, but I still think it's the players who need more educating about the warning signs and getting out of that "digging in" mentality.
'I must stress, however, in no way would I discourage anyone from playing the game that has given me so much. Also in no way do I regret anything about my rugby career, and I wouldn't change a thing.'
Find out more about sport and epilepsy.