MND: What We Know, What We Don’t, and If It’s Linked to Sports

Motor Neurone Disease (MND) has returned to the national spotlight following a series of high-profile developments.

Former NRL player Jai Arrow was forced to retire after being diagnosed with the neurodegenerative disease, and just weeks later, former AFL player Neale Daniher died after his 13-year battle with MND.

Daniher’s death drew tributes from across the country and the Victorian Parliament. He was also awarded Australian of the Year and established FightMND to find a cure for the disease.

Among those paying tribute was Labor MP Emma Vulin, who was diagnosed with MND in 2024. Speaking in Parliament, Vulin honoured Daniher’s contribution to MND awareness and fundraising, describing the lasting impact of his advocacy.

The developments have once again raised questions about what causes MND and whether participation in contact sports can increase the risk of developing the disease.

What is MND and How Does it Affect People?

MND is an umbrella term for a group of neurodegenerative diseases that affect the motor neurons in the brainstem and spinal cord.

“These are the nerve cells that control voluntary movement, including the muscles we use to walk, use our hands, speak, swallow, and breathe,” says University of Queensland researcher Shyuan Ngo, in an interview with The Epoch Times.

As these neurons progressively deteriorate and die, people with MND gradually lose muscle function and the ability to perform everyday tasks.

Early symptoms often include muscle weakness, stumbling, difficulty holding objects and slurred speech. At later stages, the disease can lead to respiratory failure and muscle paralysis.

According to the associate professor, understanding the cause of the condition remains one of the biggest challenges facing researchers. It is also a reason why there is no cure.

“We do know that some people are at increased risk because of inherited genetic variants that run in families,” Ngo said.

“We also know that some people diagnosed with MND have disease-associated genetic variants even without a clear family history.”

However, genetics alone does not explain most cases of MND, accounting for only about 10 percent of cases.

Ngo says the disease is likely caused by a complex interaction of factors, including genetic susceptibility, ageing, biological vulnerability, and environmental or lifestyle exposures.

“We don’t know an exact cause, and it is likely a combination of factors that come together to trigger the onset of MND. We are always working with a moving target,” Ngo said.

“This uncertainty is one of the major challenges in the field.”

A Link Between MND and Contact Sports?

The associate professor said some large population studies have reported a link between traumatic brain injuries and later diagnoses of MND or Amyotrophic Lateral Sclerosis (ALS).

“There is evidence that repeated head impacts and traumatic brain injury are associated with increased risk of some neurodegenerative conditions,” Ngo said.

Similar findings have emerged in sports research.

A recent international study in the British Journal of Sports Medicine examined 45 research papers and concluded that athletes in high-impact sports, particularly those involving head impacts, had a four- to 15-fold increased risk of developing MND.

The study identified soccer, rugby, and American football as key sports where the risk of MND is elevated.

However, Ngo cautioned that the progression from head injury to MND is not necessarily linear.

“Recent evidence suggests that this increased risk may be strongest in the first two years after the injury,” she said.

“[This] raises the possibility that, in some cases, the injury may not be causing MND, but may instead, occur because of early, undiagnosed MND-related changes, such as subtle weakness, impaired balance or falls.”

Yet researchers stress that the vast majority of people who experience a concussion or traumatic brain injury do not go on to develop MND. Similarly, most people diagnosed with MND do not have a clear history of repeated head trauma.

Likewise, the international study highlights the potential for a “plausible association” for physical trauma and MND, but they also cautioned that particular relationships are unclear at this stage.