What is motor neurone disease? What causes it, symptoms, life expectancy, why do rugby players get it - as Lewis Moody shares diagnosis

There has been previous research about rugby’s possible link to the fatal disease. A 2022 University of Glasgow study found that compared with the general population, a subset of former Scottish international rugby players had a 15-fold increased risk of developing MND.

The group had a roughly two-and-a-half times higher risk of neurodegenerative illness than predicted, according to research findings published in the Journal of Neurology, Neurosurgery, and Psychiatry. However, player position did not affect risk.

Brian Dickie, head of research development at the Motor Neurone Disease Association, said the findings supported earlier data on elevated risk in football players. However, he acknowledged that the study was "considerably smaller" and raised a few questions. He told the BBC: "For example, it is not clear exactly how many players were diagnosed with MND, though from the information provided, that absolute number will be small.

"It is also surprising that there were no cases reported in the larger control group, as MND is the most common neurodegenerative disease of mid-life. Moreover, we know that the vast majority of cases of MND involve a complex mix of genetic and environmental risk factors, so the level of genetic risk may be different in high-performance athletes compared with the general population.”

He added that research needed to extend to bigger populations and a “close collaboration between researchers and rugby representative bodies across multiple countries”.

What is motor neurone disease?

Motor neurone disease (MND), also known as amyotrophic lateral sclerosis (ALS), is a progressive neurodegenerative disorder that affects nerve cells (neurones) responsible for controlling voluntary muscle movements. It primarily affects the motor neurones in the brain and spinal cord, leading to the degeneration and eventual death of these cells.

As motor neurones deteriorate, the communication between the brain and muscles is disrupted, causing progressive muscle weakness, loss of coordination, and difficulties with speech, swallowing, and breathing. The disease can vary in its presentation and progression from person to person.

In rare cases, some sufferers can live for decades. For example, the renowned English theoretical physicist, cosmologist and author, Professor Stephen Hawking, was diagnosed at age 21 but lived to be 76.

Charity Marie Curie says a person with MND will usually die between two to three years after diagnosis, but this can vary from person to person.

Which famous rugby players have died from motor neurone disease?

Several famous rugby players have died from (or have) motor neurone disease. Scottish rugby union lock Doddie Weir died in 2022, aged 52, after being diagnosed in December 2016.

South Africa scrum-half Joost van der Westhuizen, who won the 1995 World Cup, died in 2017 after he announced he had the disease in 2011. Former Queensland and Australian rugby league player Carl Webb died aged 42 in December 2023 after a four-year battle with the disease.

Former Gloucester lock Ed Slater retired from rugby union in July 2022 aged only 33 after being diagnosed with MND. And now former England captain Lewis Moody has shared he has been diagnosed with the disease.

What are the symptoms of motor neurone disease?

The NHS says these include the following:

• Weakness in your ankle or leg — you might trip, or find it harder to climb stairs.
• Slurred speech, which may develop into difficulty swallowing some foods.
• A weak grip — you might drop things, or find it hard to open jars or do up buttons.
• Muscle cramps and twitches.
• Weight loss — your arms or leg muscles may have become thinner over time.
• Difficulty stopping yourself from crying or laughing in inappropriate situations.

These symptoms can appear gradually and may not be obvious at first. People who experience muscle weakness should see a GP, the NHS says. Although this is unlikely to be caused by MND, being diagnosed early can help people access the care they need.

What causes motor neurone disease?

The exact cause of motor neurone disease is not fully understood. However, research suggests that a combination of genetic and environmental factors may play a role in the development of MND.

• Genetic factors: In some cases, MND can be inherited due to certain genetic mutations. Approximately 5-10 per cent of MND cases are linked to specific genetic mutations. The most well-known genetic form of MND is familial MND (familial ALS), where the disease runs in families. Several genes have been identified that can contribute to the development of familial MND.
• Environmental factors: Various environmental factors have been studied for their potential association with MND, although the evidence is inconclusive. Some factors suggested as potential environmental contributors include exposure to certain toxins, chemicals, heavy metals, and viral infections. However, more research is needed to establish a clear causal relationship.

It is important to note that in the majority of cases, MND occurs sporadically without a clear family history or identifiable cause. The interplay between genetic predisposition and environmental factors in the development of MND is an active area of research, but further investigation is required to understand fully the complex causes.

Why do rugby players get MND?

Rugby players may get MND due to head trauma, specifically multiple concussions, that cause changes in blood proteins linked to neurological conditions like MND. Research suggests retired players with a history of concussions show significantly higher levels of certain proteins associated with MND, while some studies also highlight a potential link between high levels of physical activity, genetic predisposition, and the disease.

High-profile cases such as Doddie Weir and Rob Burrow have brought this issue to the forefront, prompting calls for changes to reduce head impacts in the sport. However, the direct causal link between head trauma and MND is still being investigated.