Source: Public Health France, the British medical journal, The Guardian, foundation-planiol.fr, AFMTelethon, Orphanet.com
We learned on Sunday June 2 of the death at the age of 41 of Rob Burrow, former British rugby union star. It was the Leeds Rhinos club with whom he had won numerous trophies which announced the sad news. Doctors diagnosed him with motor neurone disease in 2019.
What are motor neuron diseases?
These are rare neurodegenerative diseases – 2,300 new cases per year in France – characterized by a progressive loss of motor neurons. They cause motor disorders and progressive paralysis which vary depending on the extent of the damage and the motor neuron affected. The most common of these diseases, 90% of cases, is amyotrophic lateral sclerosis (ALS), also called Charcot disease.
Rapidly progressive – patients with ALS die on average within 30 months of the onset of symptoms – it is characterized by:
- A decrease in muscular strength which leads to paralysis of the limbs, then the trunk and the respiratory muscles;
- Amyotrophy, or muscular atrophy;
- Spasticity: involuntary muscle stiffness.
Other motor neuron diseases include:
- primary lateral sclerosis: degeneration of the motor neurons of the cerebral cortex without damage to the motor neurons of the spinal cord. This absence of damage to the motor neurons of the spinal cord differentiates it from ALS;
- Progressive muscular atrophy is characterized by isolated damage to the lower motor neuron, including progressive flaccid weakness, muscle atrophy, fasciculations (brief muscle contractions) and reduced or even absent tendon reflexes.
- Progressive bulbar palsy affects the neuronal network of the lower brainstem and manifests as paralysis of the muscles of the tongue, pharynx, larynx and atrophy of the tongue.
- Kennedy disease or X-linked bulbospinal muscular atrophy affects men in adulthood. It combines progressive muscle weakness and hormonal disorders. It is due to a genetic anomaly located in the gene coding for the androgen receptor, explains AFM Téléthon.
No curative medicine
There is currently no cure for motor neurone diseases. Treatment is symptomatic and multidisciplinary (physiotherapy, psychological support, non-invasive respiratory ventilation, etc.). Riluzole is the only drug available that can save ALS patients a few months of life.
The risk factors are genetic and environmental – even if they remain poorly known and difficult to identify. Occupational exposure to lead could play a role as well as exposure to pesticides in agriculture.
Is rugby to blame?
Can intensive rugby play a role in the onset of motor neurone disease? The cause is the concussions, sometimes repeated, suffered by players. “In the event of premature resumption of sporting activity, there may persist a reduction in the player’s physical and intellectual performance, which thus increases the short-term risk of a new concussion and/or a new injury. In the longer term, the repetition of concussions would have a cumulative effect on brain dysfunction with ultimately irreversible damage and social and professional repercussions. explained the French study rugby.com in 2021.
In 2022, researchers from the University of Glasgow (Scotland) published in the British medical journal the results of a study on the brains of rugby players. They examined the medical records, over 30 years, of 412 former international players aged 30 and over, which they compared to those of 1,236 individuals from the general population. Results: rugby players were twice as likely to suffer from dementia. Even more serious, they were 15 times more likely to suffer from motor neuron disease than the general population. The scientists had called for “radical changes” in rugby to reduce the risk of head impacts and cranial injuries, such as stopping all contact training during the competitive season or limiting the number of matches in which players must participate.
