The New Brunswick government says its report on a mystery brain illness affecting hundreds of people will be delayed until late December, but patients will get what they’ve called for — a review of all data by federal health officials.
The office of the chief medical officer of health in New Brunswick was expected to release a report on its investigation into 222 cases of undiagnosed neurological illness, along with recommendations, by the end of the summer.
But the Department of Health announced its adjusted timeline in a news release late Friday.
“As New Brunswick’s Office of the Chief Medical Officer of Health finalizes its environmental analysis report, the [Public Health Agency of Canada] has been asked to conduct a review of all the data collected as part of this investigation in accordance with a request from patient representatives,” the release said.
Stacie Quigley Cormier of Dalhousie Junction, whose stepdaughter Gabrielle, 23, is one of the youngest patients suffering symptoms, described the news as “a big win.”
Patient supports delay reporting on investigation into unknown neurological illness
Gabrielle suffers from poor concentration and memory and lost peripheral vision and needs to use a cane or wheelchair to move around.
In an open letter in June, Quigley Cormier and Sarah Nesbitt, who serve as co-liaisons between patients and the government, had called on Premier Susan Holt to intervene in the investigation after learning that the department sent only aggregated data to the Public Health Agency of Canada, known as PHAC, for scientific review, instead of raw data.
In health care, aggregate data refers to the summarized, combined information from multiple individual patient records or sources. It’s used to understand trends and patterns at a population level, rather than focusing on individual patients.
Dr. Alier Marrero, the Moncton-based neurologist of the 222 patients being reviewed, and one of the specialists who first sounded the alarm about a possible mystery illness about five years ago, had also sent an urgent request to provincial and federal officials in June that all raw data be shared with PHAC.
He argued it would be “nearly impossible for PHAC to reach any conclusion or meaningful recommendations with such limited and partially interpreted set of information.”
The main purpose of the investigation announced in March is to further understand concerns Marrero has raised regarding elevated levels of certain environmental substances, such as heavy metals and the herbicide glyphosate, in some patients, officials have said.
According to Nesbitt, the department had “cherry picked” information and used phrases such as “higher than normal levels” without sending the federal agency actual numbers.
That “doesn’t give the full scope of what’s happening,” she told CBC News in an interview from her home in Canaan Station.
“With the raw data in front of the professionals, they’re able to assess the situation a lot better.”
It was the government of New Brunswick that asked the office of the chief medical officer of health of health to formally engage the Public Health Agency of Canada to review all of the data, department spokesperson Meghan Cumby confirmed in an email. “This request was submitted to the Public Health Agency of Canada in early August,” she said.
In a statement, Health Minister Dr. John Dornan said the chief medical officer of health, Dr. Yves Léger, and his staff have done “significant and important work to date on the analysis and incorporation of the Public Health Agency of Canada’s [initial] feedback.”
The province asked the federal agency to review all of the data, he said, “so we can draw on every available expertise to better understand these complex cases.”
Nesbitt said she and Quigley Cormier learned the news during a meeting with Holt, Dornan and Deputy Health Minister Eric Beaulieu last Tuesday, prior to the announcement, and shared it with patients and their families.
Some people were initially discouraged by the delayed report, she said, noting some patients are getting sicker and about 50 have died.
“But what’s behind the delay is we got what we wanted — we wanted all raw data,” Nesbitt said, adding that “a lot of work can be done in those few extra months.”
Patients continue to lobby for a formal public health investigation, led by federal scientists, to figure out what’s making them sick, said Quigley Cormier.
According to Marrero, about 500 patients across seven provinces are now suffering unexplained neurological symptoms, ranging from painful muscle spasms and hallucinations, to memory loss and behavioural changes. Some have high levels of heavy metals, herbicides, and rare antibodies.
“A formal public health investigation by definition looks to identify a cause of a public health threat through unbiased inclusionary comprehensive data collection and a commitment to further testing, which is different than our experience with [Public Health New Brunswick] to date,” Quigley Cormier said in an emailed statement.
The department spokesperson did not respond to questions about whether this is being considered, or why.
PHAC spokesperson Anna Maddison told CBC News that provinces and territories take the lead on public health responses within their jurisdictions.
“PHAC is available to support provinces and territories, upon their request,” she said in an emailed statement.
In June, the scope of PHAC’s support to New Brunswick was limited to a scientific review of the province’s analysis of its data, Maddison said.
In August 2025, at the request of the office of the chief medical officer of health, PHAC agreed to undertake “a review and independent analysis” of all the available data, “including, but not limited to, the environmental-related data,” she said.
This work will involve experts from both PHAC and Health Canada, including scientists, epidemiologists, and medical advisers “with relevant subject-matter knowledge and expertise in public health investigations,” Maddison said.
Existing PHAC and Health Canada operating budgets will cover the associated costs, she said. She did not say how much those costs are expected to be.
In 2021, the office of the chief medical officer of health studied an initial group of 48 patients, primarily clustered on the Acadian Peninsula and in the Moncton region, and found no evidence of a common illness, according to a report issued in 2022.
Earlier this year, a scientific study that reassessed 25 of 222 patients diagnosed by Marrero as having a “neurological syndrome of unknown cause” reached a similar conclusion. The report, published in the Journal of the American Medical Association, or JAMA Neurology, found all of the cases were attributable to well-known conditions, such as Alzheimer’s and Parkinson’s, traumatic brain injury, and metastatic cancer.
But the premier said the province would push ahead with its own investigation. “There’s too many unanswered questions for us to stop the work that Public Health is doing to be able to provide patients — and potentially future patients — with the information they need about what’s causing these illnesses,” Holt said at the time.
Public Health is now working to get a formal data-sharing agreement in place that will protect patient privacy, the province said.
“Timelines for the federal agency’s review will depend on getting the consent of patients to allow the sharing of data,” the news release said.
“From the start of our investigation, we have been clear about our objective to develop a robust understanding of what the data is telling us, which will help us determine what next steps are needed to support affected patients and their families,” the chief medical officer of health said in a statement.
“The work has been underway for several months, and we’ve received valuable feedback from our partners throughout the process. Taking the time to reflect that input in the final report is essential to ensuring the findings are as thorough as possible,” Léger said.
