No evidence of new brain disease, officials say
Health officials in New Brunswick say they found no proof of a new brain illness. The conclusion follows a long investigation into reports of unexplained neurological symptoms across the province.
The findings add to earlier research. Those studies suggest patients may have known medical conditions rather than a new disease.
Review of patient cases
The provincial review examined 222 patients identified by neurologist Dr Alier Marrero. Around 500 people across New Brunswick and other provinces had reported symptoms he described as unexplained.
Officials compared test results from these patients with data from the wider Atlantic Canada population. As a result, they found no unusual patterns linked to a shared illness.
No link to toxins found
The report rejected claims that herbicides or heavy metals caused the symptoms. Officials said herbicide levels fell within normal ranges.
Some patients showed higher metal levels. However, officials said testing methods were inconsistent. Because of that, they could not confirm a health impact.
Testing limits and second opinions
Health officials said the review faced limits. Some early tests did not follow proper guidelines. In addition, most patients did not receive follow-up testing over time.
Nearly 60 percent of patients had also seen a second neurologist. None of those specialists raised concerns about a new disease.
Going forward, the province will require two specialist reviews for any unexplained neurological case.
Reaction from health officials
Chief Medical Officer Dr Yves Léger said evidence continues to point toward diagnosable conditions. He stressed that patient care remains a priority.
He also said the findings will be shared with Dr Marrero and the Public Health Agency of Canada. A federal review will follow.
Patient concerns remain
Some patients expressed concern about the study’s limits. Environmental advocate Sarah Nesbitt said a few patients did show elevated metal levels.
Still, she said the report could help patients get support and clearer answers. She added that trust in the medical system has weakened for some patients.
Past studies reached similar conclusions
This is the second provincial study on the issue. A 2022 report found no shared exposure and linked symptoms to different illnesses.
Last year, a JAMA Neurology paper reviewed 25 cases. It found conditions such as cancer and dementia. Lead author Dr Anthony Lang said the new report supports those conclusions.
Marrero’s response awaited
Dr Marrero did not respond to requests for comment. He has previously said other scientists once supported the idea of a new syndrome.
He also said he remained involved when others stepped away.
