Nearly 20 years ago, retired English professional soccer player Jeff Astle, aged 59, choked to death at his daughter’s home near Burton-on-Trent.

The former centre-forward for West Bromwich Albion had experienced dementia for several years, and in a landmark ruling, the coroner declared he had died from an “industrial disease” resulting from heading balls.

It was later claimed that Mr Astle had succumbed to chronic traumatic encephalopathy (CTE) — a neurodegenerative disease once associated only with combat-based sports such as boxing.

The case spurred clinicians to question whether CTE, which is caused by repeated blows to the head resulting in traumatic brain injury (TBI), was a widespread hazard of contact sports, including Australian rules football and rugby, and American gridiron.