A top neurologist has called on the New South Wales government to list motor neurone disease (MND) as a notifiable disease amid suspicions a cluster of diagnoses in the state could be linked to something in the environment.
Prof Dominic Rowe, a neurologist at Macquarie University, has treated 889 MND patients – many from the NSW irrigation town of Griffith – in the past decade.
Rowe is concerned the prevalence of cases in the region could be linked to something in the environment, with researchers investigating links to blue-green algae, pesticides and heavy metals.
But he says his team is limited in their research because MND is not listed as a notifiable disease – one that must be reported to authorities.
If MND were given notifiable disease status, researchers could access location data that would allow them to see where people with the disease live in relation to places like lakes and water bodies, Rowe said.
They have access to “observational” data from patients, but Rowe says this is “not comprehensive”.
“If we just close our eyes and continue holding people’s hands as they die, that’s not satisfactory at all,” he says.
MND is a progressive neurological disorder that leaves people unable to walk, speak, swallow and ultimately breathe.
In Australia, MND has increased in prevalence by around 250% over the past three decades, according to Rowe.
While 5-10% of cases are believed to be genetic, Rowe says he “strongly suspects” something in the environment is driving a rise in the remaining sporadic (non-genetic) cases.
The data from a notification listing would help researchers zero in on cases and scour the surrounding environment for clues about their cause, Rowe says.
He says if an environmental cause can be identified, prevention – and even a cure – may be possible, and that “we should move heaven and earth” to get there.
Not far from Griffith is a lake surrounded on two sides by picturesque farming land. It has become a focal point for researchers looking into high rates of MND in the region.
Michelle Vearing says her family visited Lake Wyangan “every other weekend” while growing up and the kids would spend hours swimming and water skiing in the water. The recreational area of Lake Wyangan is operated by the Griffith city council.
Vearing lost her grandfather and mother to a genetic form of MND and is now supporting her sister Tania Magoci as she battles the disease.
Vearing is a volunteer with the Griffith MND support group, which organises many of its activities through social media. Its Facebook page contain a mix of tributes to people who have died, requests for urine and blood donations for research trials, and fundraising sales of everything from hand-stitched quilts to a treasured rugby league jersey.
“Nearly everyone in town knows someone who has or has passed away from MND,” Vearing says.
Out of the 30 people in the area who have passed away from the disease over the past decade, many had strong connections to Lake Wyangan or other nearby bodies of water, Vearing says.
In recent years the lake has become prone to blooms of cyanobacteria, commonly known as blue-green algae, a natural feature in Australian waters and one experts say is thriving as the climate becomes hotter and drier.
So far the NSW government has rebuffed the proposal to list MND as a notifiable disease.
In June, the NSW health minister Brad Hazzard agreed to meet with representatives from the Macquarie University research team to discuss the proposal, but the meeting was postponed due to the state’s coronavirus outbreak.
In a statement, the NSW health department said MND did not meet criteria to be made notifiable, which included “the potential for outbreaks, a necessity for urgent public health response and preventability”.
But experts say a neurotoxin linked to MND, which researchers from the University of Technology Sydney (UTS) found in Lake Wyangan in 2019, could be cause for concern and requires more research. The toxin, beta-methylamino-L-alanine, or BMAA, is produced by blue-green algae.
Ken Rodgers, an associate professor of pharmacology at UTS, does not think the science is “100% done and dusted” on the question of whether BMAA causes neurological disease. But he says recent studies are “quite compelling in terms of implicating BMAA in neurodegeneration” and that scientists should be gathering information on where the toxin is located and how much there is.
The NSW health department said links between blue-green algae and MND were reviewed in 2015 by scientists from Water Research Australia (WRA), who concluded “the theory remains unproven” after reviewing more than 200 papers published on BMAA.
An updated factsheet from WRA released this month also notes “there is a lack of scientific consensus that causality has been established” but it acknowledges cyanobacterial blooms are becoming increasingly common and “pose a threat to modern water supply systems”.
“It is thus important to understand not only how they may be removed from the water supply … but also how these toxins affect public health,” the factsheet says.
A growing body of evidence, researcher says
Dr Rachael Dunlop, an Australian senior research fellow who moved to the US to study links between BMAA and MND, says there is a growing body of evidence to support the theory.
“If you look at the amount of publications that have appeared in the peer reviewed literature on this particular subject, there’s been a huge increase in the last five to seven years,” she says.
The “most compelling evidence to date for a direct connection between BMAA exposure and MND” was published in 2020, she says, in a study demonstrating BMAA ingestion caused nerve damage very similar to that seen in the early stages of disease in MND sufferers.
“There’s studies … that have found (BMAA) in postmortem brain samples from people who died of sporadic motor neurone disease.
“But you won’t find it in patients that didn’t die from motor neurone disease. And you won’t find it in people that had an unrelated neurodegenerative disease.”
And in one study from the US, researchers found people who live around Lake Mascoma in New Hampshire, which has a history of blue-green algal blooms, were “25 times more likely to contract motor neurone disease”, Dunlop says.
Dunlop says not everyone who is exposed to the toxins in blue-green algae will suffer from MND, but scientists think BMAA may be “a trigger in susceptible individuals”.
“I don’t want to scare people by saying, if you even pass this thing in the street you’re going to get sick. That’s not the case. But it certainly is a factor in a serious disease for which there is not currently a cure.”
In NSW, Murray MP Helen Dalton says when a bloom starts at Lake Wyangan the surface of the water becomes slimy and green, “bubbling and festering”, and a rotten smell drifts through the surrounding farmland.
For a period in 2017, when the local council drew Griffith’s water supply from the lake, the smell came out of people’s taps, Dalton says.
Griffith city council and the federal government announced $7m of funding in August to improve water quality at the lake, but Dalton says it will take time for the work to be completed.
With hotter and drier climatic trends creating conditions for blue-green algae to thrive, Dunlop says it is likely more people could be exposed to BMAA.
And if there is an environmental link for the disease, Rowe says it is imperative researchers find it before more people are exposed.
He says every one of his patients has left him with questions.
“Why does this 38-year-old mother of two die? Why does this 55-year-old barrister die with sporadic motor neurone disease?” he says.
“If you are numb to the tragedy of this disease and what it does to people and their partners and their families, you shouldn’t be looking after these people.”