Concussion is not a maths problem. Cause and effect don't always equate

The personal testimonies of Steve Thompson, Alix Popham and Michael Lipman this month have been harrowing. They are shocking insights into minds and lives that are being systematically destroyed by their illnesses

How rugby responds to the evidence, both the academic and from players ‘self-reporting cognitive issues’, is a question for the rugby authorities to tackle.

Slowly but surely the spectre of concussion in sport and, with it, the fear of possible long-term consequences creeps closer to home.

It was heartbreaking and alarming enough when ageing footballers, so many of England World Cup winners from 1966 among them, and American football players on another continent and from another world were the ones suffering. Now it is former rugby players in their 30s and 40s in these islands being diagnosed with early-onset dementia.