Medical specialists have discovered that Billy Guyton, a former New Zealand rugby player who passed away last year, is the country's first confirmed professional rugby player to have been diagnosed with chronic traumatic encephalopathy (CTE), a degenerative brain disease.

Guyton, who played for Auckland Blues and New Zealand Maori, was found to have stage two CTE after his brain was donated to the University of Auckland's "Brain Bank" by his family.

CTE, associated with repetitive head injuries, can lead to mood swings, dementia, and depression. Guyton's father revealed that his son experienced symptoms consistent with CTE, including sensitivity to light and emotional distress.

This revelation coincides with legal action taken by nearly 300 former rugby players, including World Cup winners Steve Thompson and Phil Vickery, alleging that rugby governing bodies failed to adequately protect players from head injuries.

Injuries from head blows are also linked to other neurological disorders. New Zealand Rugby stated that they are actively working to mitigate the risks of head impacts and supporting research on the long-term effects of rugby participation on brain health.