Latest news with #AlierMarrero
CBC
08-05-2025
- Health
- CBC
What's making New Brunswickers sick? Premier Susan Holt intends to find out
Social Sharing Premier Susan Holt says it's critical the province push ahead with its investigation into what's making some New Brunswickers sick, despite a new scientific study that found no evidence of a mystery brain disease. "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 told reporters Thursday in Fredericton during her weekly update on U.S. tariffs. She was responding to questions about a report, published Wednesday in the Journal of the American Medical Association, known as JAMA. Thirteen Canadian doctors and researchers reassessed 25 of the 222 patients diagnosed by Moncton neurologist Dr. Alier Marrero as having a "neurological syndrome of unknown cause." They concluded all of the cases — 14 living and 11 who have died — were attributable to well-known conditions, such as Alzheimer's traumatic brain injury and cancer. WATCH | 'There might not be one answer, there might be multiple things at play here,' Holt says: Holt says N.B. to keep studying mysterious cluster of sick people, despite report 2 hours ago Duration 0:55 A report in the Journal of the American Medical Association says there's no mystery brain disease in New Brunswick, but Premier Susan Holt says the province's own investigation will continue. Their analysis of the patients also provides "strong evidence against a common cause of the patients' conditions, such as exposure to an environmental toxin," because of the wide range of problems, they wrote. The work the province is doing "remains critical," Holt said. "We need to work with the patients and the population of New Brunswick to answer the question about what is making New Brunswickers sick," she said. "The study didn't answer that question." Government report due this summer In March, the New Brunswick government launched the "data analysis phase" of its investigation into undiagnosed neurological symptoms that Marrero says are now affecting some 500 people in seven provinces. The investigation will consider whether environmental substances, such as the herbicide glyphosate or heavy metals, are a factor. "It is anticipated the results of the analysis will soon be shared with the Public Health Agency of Canada," Dr. Yves Léger, New Brunswick's chief medical officer of health, said in an email. A public report with recommendations is expected this summer. "I think that the work that Public Health is doing and the support we're getting from the Public Health Agency of Canada is critical for us to continue to try to answer those questions for New Brunswickers, knowing that there might not be one answer," Holt said. "There may be multiple things that are at play here in different areas of the province and in different situations." The premier did not say whether the province will help Marrero's hundreds of other patients to get a second opinion, as the study urges. In an emailed statement, New Brunswick Medical Society president Dr. Lise Babin said, "We trust that the process that has recently been put in place by Public Health New Brunswick will consider all relevant research and data related to this ongoing issue." Holt pledged last summer to launch a transparent scientific investigation if elected in the October provincial election. New Brunswickers suffering from unexplained symptoms and the doctors trying to help them had "been ignored" by the Blaine Higgs government "for far too long," she said in a statement at the time.
The Guardian
08-05-2025
- Health
- The Guardian
Canada medical mystery takes twist as study finds no evidence of brain illness
A new peer-reviewed scientific study has found no evidence of a mystery brain disease in the Canadian province of New Brunswick, suggesting instead a troubling combination of 'misdiagnosis and misinformation'. The research comes as the Maritime province prepares its own assessment of more than 220 suspected cases, in the hope of giving families some answers to a medical mystery that has gripped the region for years. The report published on Wednesday in the Journal of the American Medical Association, known as Jama, is an independent reassessment of 25 cases diagnosed by Moncton-based neurologist Alier Marrero from within the broader sample of 222 patients. The authors, affiliated with the University of Toronto, New Brunswick's Horizon health network and other Canadian institutions, found that those within the cohort were misdiagnosed and had common neurodegenerative diseases, such as Alzheimer's and Parkinson's, functional neurological disorder, traumatic brain injury and metastatic cancer. The findings, however, are unlikely to tamp down speculation from families that the report once again ignores their suspicions of environmental contamination in the region. Health officials in New Brunswick first warned in 2021 that more than 40 residents were suffering from a possible unknown neurological syndrome, with symptoms similar to those of the degenerative brain disorder Creutzfeldt-Jakob disease. Those cases were referred to Marrero after the initial physicians were initially stumped by the symptoms displayed by their parents. A year later, however, an independent oversight committee created by the province determined that the group of patients had most likely been misdiagnosed and were suffering from known illnesses such as cancer and dementia. A final report from the committee, which concluded there was no 'cluster' of people suffering from an unknown brain syndrome, signalled the end of the province's investigation. But earlier that year, the Guardian reported that a top federal scientist worried there was 'something real going on' in New Brunswick. Another said the investigation 'was shut down' and that caseloads were higher than officially acknowledged. 'I don't think it is helpful to suggest or point to who or why – suffice to say that we were prepared to marshal both financial and human scientific resources to tackle the mystery, but they were declined,' the scientist wrote. According to a February 2025 letter Marrero wrote to federal and provincial officials, seen by the Guardian, the number of patients suffering from unexplained neurological symptoms has since jumped to 507 across New Brunswick, Nova Scotia, Prince Edward Island Newfoundland, Ontario, Quebec and Alberta. Several under the age of 45. The new study found that 'well-known conditions were identified in all 25 cases, including common neurodegenerative diseases, functional neurological disorder, traumatic brain injury and metastatic cancer,' adding that a study of 11 autopsy cases led to the conclustion that 'a new disease was extremely unlikely, with a probability less than .001'. Patient advocacy groups have rejected the idea of a new 'mystery illness', instead arguing that the cases are linked by environmental contaminants. But the researchers say they do not believe the patients were made ill by exposure to something in the environment, such as herbicides or heavy metals like mercury. They determined that 'misdiagnosis and misinformation become inextricably entwined and amplify harm exponentially', noting that more than half of the people eligible for the study declined to participate. They also blamed 'inaccurate clinical assessments and an over-reliance on ancillary testing' for perpetuating the idea of a 'mystery illness' and said they found 'meaningful discrepancies' in case histories. Marrero said in a statement he is 'in profound disagreement with the study conclusions' and has 'many questions regarding the methods and the content', adding that he was 'appalled' that an investigation with a 'small number' of patients has been conducted without his knowledge. Susan Holt, the province's premier, pledged a fresh and 'thorough' investigation after taking office last last year. 'I think we need to be doing everything we can to shed some light on this and find a way to stop what's making people sick,' she said at the time. New Brunswick's chief medical officer of health Dr. Yves Léger, said in a statement the Jama study doesn't change his office's intention to complete its own investigation into the 222 cases, which Marrero has officially referred to the province. Updates will be posted on the province's new website, and a public report with recommendations is expected in the coming months.
CBC
08-05-2025
- Health
- CBC
No mystery brain disease in New Brunswick, study finds
A new scientific study has found no evidence of a mystery brain disease in New Brunswick, says a report published in the Journal of the American Medical Association. Instead, an independent reassessment of 25 of 222 patients diagnosed by Moncton neurologist Alier Marrero as having a 'neurological syndrome of unknown cause' concluded that all of the cases could be attributed to well-known conditions.
Yahoo
07-05-2025
- Health
- Yahoo
Mysterious brain diseases in Canada weren't a mystery after all
Six years ago, a Canadian neurologist claimed to notice strange symptoms in a cluster of patients in New Brunswick, a province bordering Maine. According to the neurologist, Dr. Alier Marrero, the patients suffered hallucinations, spasms, rapid memory loss and the sensation that bugs were crawling underneath their skin, but their symptoms and brain scans didn't neatly fit an existing diagnosis. In other words, the cases were a mystery. But since then, neurologists who have reviewed the cases have identified clear diagnoses, including Alzheimer's, Parkinson's and cancer. A study published this week in JAMA Neurology reinforces those findings, putting the probability of a mystery disease at roughly 1 in a million. Doctors working on the study evaluated 25 people who had been identified as part of the New Brunswick cluster. Eleven of the patients had died, so neuropathologists used autopsies to determine their illnesses. For the 14 living patients, neurologists relied on cognitive assessments, among other tests. They concluded that all of the patients had well-known conditions such as Alzheimer's, Parkinson's, cancer, traumatic brain injuries or post-concussion symptoms. 'We really felt we had a good explanation for 100% of the cases,' said an author of the study, Dr. Anthony Lang, a neurologist at University Health Network's Krembil Brain Institute. However, some doctors worry it won't be enough to quash speculation that the cases have an unknown origin — a theory many patients and their families have clung to. According to the study authors, 52 people identified as part of the New Brunswick cluster refused second opinions, and 42 more didn't respond to the authors' reaching out. The study attributes that to declining trust in health institutions and the spread of misinformation on both traditional and social media. 'These were examples of misdiagnosis that then led to misinformation. And sadly, the physician involved continues to believe and convince the patients and families that they have a mysterious illness,' Lang said. Marrero took issue with the study and its findings in a statement. 'I am in profound disagreement with the study conclusions and have many questions regarding the methods and the content,' he said. 'I am sure that our patients, families, and communities share the same very serious concerns.' Dr. Valerie Sim, an associate professor of neurology at the University of Alberta who wasn't involved in the study, said there has been no proof that the patients' illnesses are related. In fact, she said, the cases are 'so broad in their description that we could all have this mysterious illness.' 'Sadly, the one thing that all the patients have in common is the same neurologist,' Sim said. 'And the patients who have been seen by other neurologists get a diagnosis of a known entity that's not a mystery.' James Mastrianni, a neurology professor at the University of Chicago who wasn't part of the research, said the study reinforces that 'a second opinion by an expert in the field is often helpful.' An ongoing investigation The mystery illness theory gained traction in 2021 when Canadian health authorities began investigating cases based on Marrero's reports. But even after the investigation determined that most patients had known conditions, some families were skeptical. In November, the premier of New Brunswick, Susan Holt, called on the province's health minister to conduct a scientific review 'into the mystery brain disease.' 'New Brunswickers deserve answers,' Holt said in a statement last year. 'We need to know what's making us sick.' Some patient advocates now believe an environmental exposure is triggering the illnesses, claiming patients' blood and urine tests show the presence of heavy metals, pesticides and rare antibodies that warrant further study. 'It wasn't ever about whether a patient could have an alternative diagnosis,' said Kat Lanteigne, an advocate from New Brunswick. 'It was what has triggered them to have this neurodegenerative disease?' Dr. Yves Léger, New Brunswick's chief medical officer of health, said in a statement Wednesday that the new study 'doesn't change my Office's intention to complete its own investigation into cases of undiagnosed neurological illness in New Brunswick.' His office has received 222 reports of cases identified as part of the cluster. Marrero said he has 'evaluated more than 500 patients in this cluster, and provided a significant amount of unequivocal, sometimes critical environmental exposure evidences, as well as rare autoimmune markers in many of them.' But Lang said that just because a substance is in blood or urine doesn't mean it caused someone's neurological symptoms. 'You don't do a shotgun approach looking for anything and everything and then finding something and claiming it's related to what the problem is,' he said. The challenge of diagnosing neurological issues Neurologists with no connection to the New Brunswick cases point to a few reasons advocates, doctors and government officials are still debating the cause of the illnesses. For one, they said, accurate diagnoses can take time. And some of the conditions detected in the study, like Alzheimer's, can have complex presentations. 'It really takes a cohesive story from the family and a timeline to understand if someone is developing dementia. There can be confusing signs on a neurologic exam,' said Dr. Kimberly O'Neill, a neurologist in the NYU Langone Health Multiple Sclerosis Comprehensive Care Center. One of the core symptoms used to identify the New Brunswick patients was rapidly progressing dementia. But families sometimes miss early signs of neurodegeneration, making it appear that dementia came on suddenly, Mastrianni said. Once debilitating symptoms arrive, patients and their families are often desperate for answers and may be reluctant to let go of the first diagnoses they get, Sim said. 'We see this all the time in medicine, that patients gravitate to a diagnosis or a group entity,' Sim said. 'That's clearly what's happening here.' The misdiagnoses are 'really a tragedy,' she added, because patients could be missing out on treatments or proper care. This article was originally published on
NBC News
07-05-2025
- Health
- NBC News
Mysterious brain diseases in Canada weren't a mystery after all
Six years ago, a Canadian neurologist claimed to notice strange symptoms in a cluster of patients in New Brunswick, a province bordering Maine. According to the neurologist, Dr. Alier Marrero, the patients suffered hallucinations, spasms, rapid memory loss and the sensation that bugs were crawling underneath their skin, but their symptoms and brain scans didn't neatly fit an existing diagnosis. In other words, the cases were a mystery. But since then, neurologists who have reviewed the cases have identified clear diagnoses, including Alzheimer's, Parkinson's and cancer. A study published this week in JAMA Neurology reinforces those findings, putting the probability of a mystery disease at roughly 1 in a million. Doctors working on the study evaluated 25 people who had been identified as part of the New Brunswick cluster. Eleven of the patients had died, so neuropathologists used autopsies to determine their illnesses. For the 14 living patients, neurologists relied on cognitive assessments, among other tests. They concluded that all of the patients had well-known conditions such as Alzheimer's, Parkinson's, cancer, traumatic brain injuries or post-concussion symptoms. 'We really felt we had a good explanation for 100% of the cases,' said an author of the study, Dr. Anthony Lang, a neurologist at University Health Network's Krembil Brain Institute. However, some doctors worry it won't be enough to quash speculation that the cases have an unknown origin — a theory many patients and their families have clung to. According to the study authors, 52 people identified as part of the New Brunswick cluster refused second opinions, and 42 more didn't respond to the authors' reaching out. The study attributes that to declining trust in health institutions and the spread of misinformation on both traditional and social media. 'These were examples of misdiagnosis that then led to misinformation. And sadly, the physician involved continues to believe and convince the patients and families that they have a mysterious illness,' Lang said. Marrero took issue with the study and its findings in a statement. 'I am in profound disagreement with the study conclusions and have many questions regarding the methods and the content,' he said. 'I am sure that our patients, families, and communities share the same very serious concerns.' Dr. Valerie Sim, an associate professor of neurology at the University of Alberta who wasn't involved in the study, said there has been no proof that the patients' illnesses are related. In fact, she said, the cases are 'so broad in their description that we could all have this mysterious illness.' 'Sadly, the one thing that all the patients have in common is the same neurologist,' Sim said. 'And the patients who have been seen by other neurologists get a diagnosis of a known entity that's not a mystery.' James Mastrianni, a neurology professor at the University of Chicago who wasn't part of the research, said the study reinforces that 'a second opinion by an expert in the field is often helpful.' An ongoing investigation The mystery illness theory gained traction in 2021 when Canadian health authorities began investigating cases based on Marrero's reports. But even after the investigation determined that most patients had known conditions, some families were skeptical. In November, the premier of New Brunswick, Susan Holt, called on the province's health minister to conduct a scientific review 'into the mystery brain disease.' 'New Brunswickers deserve answers,' Holt said in a statement last year. 'We need to know what's making us sick.' Some patient advocates now believe an environmental exposure is triggering the illnesses, claiming patients' blood and urine tests show the presence of heavy metals, pesticides and rare antibodies that warrant further study. 'It wasn't ever about whether a patient could have an alternative diagnosis,' said Kat Lanteigne, an advocate from New Brunswick. 'It was what has triggered them to have this neurodegenerative disease?' Dr. Yves Léger, New Brunswick's chief medical officer of health, said in a statement Wednesday that the new study 'doesn't change my Office's intention to complete its own investigation into cases of undiagnosed neurological illness in New Brunswick.' His office has received 222 reports of cases identified as part of the cluster. Marrero said he has 'evaluated more than 500 patients in this cluster, and provided a significant amount of unequivocal, sometimes critical environmental exposure evidences, as well as rare autoimmune markers in many of them.' But Lang said that just because a substance is in blood or urine doesn't mean it caused someone's neurological symptoms. 'You don't do a shotgun approach looking for anything and everything and then finding something and claiming it's related to what the problem is,' he said. The challenge of diagnosing neurological issues Neurologists with no connection to the New Brunswick cases point to a few reasons advocates, doctors and government officials are still debating the cause of the illnesses. For one, they said, accurate diagnoses can take time. And some of the conditions detected in the study, like Alzheimer's, can have complex presentations. 'It really takes a cohesive story from the family and a timeline to understand if someone is developing dementia. There can be confusing signs on a neurologic exam,' said Dr. Kimberly O'Neill, a neurologist in the NYU Langone Health Multiple Sclerosis Comprehensive Care Center. One of the core symptoms used to identify the New Brunswick patients was rapidly progressing dementia. But families sometimes miss early signs of neurodegeneration, making it appear that dementia came on suddenly, Mastrianni said. Once debilitating symptoms arrive, patients and their families are often desperate for answers and may be reluctant to let go of the first diagnoses they get, Sim said. 'We see this all the time in medicine, that patients gravitate to a diagnosis or a group entity,' Sim said. 'That's clearly what's happening here.'
