N.B. report finds herbicides, heavy metals not the cause of 'most' undiagnosed neurological illnesses
Evidence suggests the 222 patients reviewed have a known illness, says chief medical officer of health
Environmental substances like herbicides and heavy metals are likely not causing the neurological symptoms reported by hundreds of New Brunswickers, an investigation by the province into the so-called mystery brain illness has concluded.
Dr. Yves Léger, the chief medical officer of health, released the final report on the investigation into 222 of the cases of "undiagnosed neurological illness" on Friday.
The investigation was launched last March to further understand concerns raised in 2023 by Moncton neurologist Dr. Alier Marrero about elevated levels of the herbicides glyphosate and glufosinate and several different metals, such as aluminum, arsenic, lead and mercury, in some patients.
"The main findings do not suggest exposure to certain environmental substances was a potential cause of illness among all or even most of the patients studied," Léger said when the report was released at a news conference in Fredericton.
Asked to clarify, Léger said the findings are based on the group of patients as a whole and don't point to any "widespread … exposures" that are "contributing to most patients' illnesses.
"We can't specifically speak to individual patients because we didn't look at individual patient files, we looked at individual [test] results," he told CBC News.
The report does not identify what is making people sick, with symptoms ranging from painful muscle spasms and hallucinations, to memory loss and behavioural changes — a situation that has prompted international headlines and heated debate for years.
But Léger said the latest findings, along with a 2022 report by the previous government on an initial group of 48 patients primarily clustered on the Acadian Peninsula and Moncton area as well as a scientific study published last May in the Journal of the American Medical Association, suggest patients are likely suffering from an illness that can be diagnosed.
The nine autopsies reviewed pointed to known conditions, such as Alzheimer’s disease, Lewy body dementia and Creutzfeldt-Jakob disease (CJD), he said.
"When we embarked on this work, we knew that it would not provide all the answers that patients were looking for. We knew it wouldn’t be end of the work that needed to be done on this file," Léger said.
Patient reviews mixed
Sarah Nesbitt, 42, of Canaan Station just north Moncton, is one of Marrero's patients and serves as a co-liaison between patients and the government. She described the report as "double edged."
Many patients are "disheartened," she said. They still don't know what's causing their illness, how to get better or how to prevent others from getting sick.
"They feel it's the same as the first [report in 2022], but at least this time around, they did find, 'some patients that had elevated levels of herbicides and heavy metals,'" she said.
According to Léger, there were "significant limitations" with the data collected by Marrero.
For example, the best type of specimen, such as blood or urine, to test for a particular substance was not always used, and "very few" patients who tested high were retested to verify the results.
Nevertheless, for herbicides, the province found about 95 per cent of the results were "within the normal or expected range" when compared to the labs' reference ranges and similar to the levels of other Atlantic Canadians.
For heavy metals, about 93 per cent of the results were within the normal or expected levels when compared with the reference ranges and most were the same or lower than a sample of Canadians "with a few elevations noted for a few metals."
Nesbitt questioned a lack of follow-up testing. She has ben sick since 2020, when she lived in Steeves Mountain, about 20 kilometres east of Moncton, and Marrero tests her every six months, she said.
"I get about 23 to 24 vials of blood every time and a 24-hour urine test," she said.
Still, patients are encouraged to know the province isn't "going to abandon" them now, she said. "There is still work to be done."
3 recommendations
The report makes three recommendations, which provide a "path forward," according to Léger.
One calls for putting a process in place to support patients in receiving a second, independent assessment and a diagnosis of their illness, which will help them get the care and followup they need.
Testing for herbicides or metals should only be conducted "when there is a clear reason, such as when symptoms are present, or a possible exposure is found," the report says. The correct type of sample should be used to provide more accurate and reliable results, and tests showing high levels should be repeated at least once.
In addition, the report recommends that a formal process be implemented, requiring two specialists to review and agree on a report of undiagnosed neurological illness in a patient.
Léger said he hopes to see all three implemented "as soon as possible."
The provincial government has also asked the Public Health Agency of Canada, or PHAC, to review the raw data of individual patients "to see if there are any trends or issues of concern," Léger said.
A timeline for the agency's work will be determined once the informed patient consent process is completed, the data-sharing agreement is in place and the data has been shared, he said.
An unidentified PHAC spokesperson declined to comment, referring all inquiries back to the province.
Nesbitt said she hopes they contact patients and "dive deeper rather than just sitting behind desks reading paperwork."
Patient co-liaison Stacie Quigley-Cormier of Dalhousie Junction, whose stepdaughter Gabrielle, 24, is one of the youngest patients suffering symptoms, is also hopeful the PHAC review will "yield [a] more accurate portrait of why there are patient clusters, atypical presentations of illness and look into environmental concerns.
"The patient reality is that there are geographical clusters, there are test results in common and there are a large portion of patients who have had tests repeated," she said in an emailed statement.
Regulatory body to determine next steps
Léger referred questions about Marrero's abilities and any possible disciplinary action to the College of Physicians and Surgeons and Vitalité Health Network.
The province does not intend to file a complaint against him, he said, noting neurology is a complex field and a diagnosis can take months or even years.
Having said that, there is "an accumulating body of … good evidence" that suggests the patients may have conditions that can be diagnosed, he said, which is "very concerning" because they are suffering and do not have a proper treatment plan.
In an unsigned emailed statement, the provincial regulatory body said it "recognizes how difficult this situation has been for the many patients affected.
"We will review the report and its recommendations carefully to determine whether any further action is required by the College," it said.
Vitalité, too, said it will "take the time to carefully review the report before determining next steps."
Patients will be kept informed, it said.
Nesbitt said the patients continue to stand by Marrero.
"I'd like people to focus on patients, not shaming and attacking a doctor that's done his best for us and has done his due diligence for his patients," she said.
Marrero did not respond to a request for comments.