O'Brien to answer Ireland's call

The 28-year-old missed five matches for club side Leinster with the condition, which affects balance and can cause vertigo or disorientation.

But O'Brien successfully completed 71 minutes of their derby victory over Munster on Sunday.

And with his bout of ill health seemingly behind him, Ireland head coach Joe Schmidt looks as though he will be able to count on his 41-cap star for the Six Nations.

"Thankfully, it's sorted," O'Brien told the Irish Independent. "I don't know if it was scary but it was very frustrating.

"Leinster have been very good with me and not rushing me back. It's felt grand and I felt very good out there.

"I wanted to play my part for the team and do my bit for the performance.

"There's been a lot of frustration over the past couple of weeks, it was more so about that than playing with any freedom."

And Leinster head coach Leo Cullen said the whole place had been given a lift by O'Brien's return.

"It's great," Cullen said.

"Even in the last few weeks Seanie's played a big role in terms of driving the group. We see him as a huge leader for the team and definitely we've missed his presence out on the field.

"It's his experience that he has as well, the presence he has and the respect he has amongst his peers, it's just fantastic to have him back."

SOURCE: rbs6nations.com