We all want answers over rugby's MND risk - but the wait goes on

Lewis Moody, 47, is the latest in a long line of players who has been diagnosed with a neurodegenerative disease that may or may not be linked to his career in collision sport.

- Andy Bull

Over the past decade I've interviewed more of these men, and their friends and families, than I ever wanted to. Many of them chose to first reveal their diagnoses in the Guardian. First there's the shock, then the sorrow, then the expressions of sympathy and support. And after all that, a lot of hard questions that are left unaddressed.

The one thing everyone involved wants is clear answers, and unfortunately, they are very hard to come by. The current science can only tell you so much. The Motor Neurone Disease Association's position is that the latest research suggests a correlation between traumatic brain injuries and MND, but that the same research has not proven that traumatic brain injuries are a cause of MND. Such injuries are just one on a long list of genetic factors and environmental factors.

Studies have found possible links with electrical trauma, mechanical trauma, high levels of exercise, exposure to assorted heavy metals and agricultural chemicals, and, yes, concussions and other traumatic brain injuries that occurred while playing sport.