The rate of motor neurone disease is climbing nationally, with hotspots in regional areas where Australians are facing even higher mortality rates – suggesting environmental risk factors are at play – according to new epidemiological analysis led by Macquarie University and published in the Medical Journal of Australia.
National data from Australian Bureau of Statistics (ABS) cause of death records show the number of deaths due to motor neurone disease (MND) has trebled since the late 1980s.
“This is the first comprehensive look at national mortality from this deadly disease, and it shows MND is now responsible for one death in every 234 across the country,” says lead author Dr Carol Lee of Macquarie’s MND Research Centre.
“The national data point to a steady increase from 238 MND-related deaths in 1986 to 781 in 2023, with no obvious factor contributing to the growing mortality,” she said.
Dominic Rowe AM, Professor of Neurology in the Macquarie Medical School and senior author of the research paper, said the study also identified clear geographic differences in MND incidence in Australia.
“MND mortality in 2019-2023 was 1.4 times higher in Tasmania and 1.2 times higher in South Australia than in New South Wales, and significantly higher in regional areas compared to major cities,” says Professor Rowe.
“About 10 per cent of people with MND have a clear family history of the disease, but genetic factors can’t explain either the nationwide increase or the regional differences. The striking increase in mortality is from sporadic disease, not genetic.”
“Higher MND mortality in regional areas compared to cities suggests that people living or working in regional areas might be exposed to risk factors that their city-dwelling counterparts don’t encounter,” says Professor Rowe.
“The regional differences mirror my clinical observation over many decades – in my opinion, environmental factors are the cause of the increasing number of MND cases.”
Until now, the lack of a compulsory national registry for MND cases has limited epidemiological and geographical analysis as well as accurate estimates of the disease burden due to MND.
This study was funded by a grant from NSW Health specifically tagged by the Minns government for research into MND, support for which was driven by Helen Dalton MP, independent member for Murray and founder of the NSW Parliamentary Friends of MND.
The authors are calling for the establishment of a compulsory state-wide registry of MND cases together with significantly greater funding for research to determine which environmental risk factors may be driving the rising incidence of MND, particularly in regional areas.
“It’s totally unsatisfactory that we still don’t know the cause,” says Professor Dominic Rowe. “This study points strongly to environmental links and we need to urgently investigate whether this means environmental contaminants or even lifestyle and recreational activities are responsible for sporadic MND.”
“Understanding the cause of MND is critical to developing therapies to stop this uniformly lethal disease – without understanding the cause, we can’t understand the disease mechanism, and without understanding the mechanism our therapies will be based on trial and error.”
“This disease will kill 800 Australian this year,” says Professor Rowe. “For every family looking after a patient with MND, we must identity the cause and develop better therapies.”