Six years ago, a Canadian neurologist noticed unusual symptoms among a group of patients in New Brunswick, a province next to Maine.
Dr. Arie Marrello reported that patients experienced hallucinations, convulsions, rapid memory loss, and a sensation of insects crawling under their skin, but these symptoms and brain scans didn’t align with existing diagnoses, making the cases puzzling.
Subsequent reviews by neurologists led to clear diagnoses, including Alzheimer’s disease, Parkinson’s disease, and cancer.
A recent study published in JAMA Neurology supports these findings, indicating that the likelihood of such mysterious illnesses is about one in one million.
The physicians involved in this study assessed 25 patients from the New Brunswick cluster. With 11 patients deceased, neuropathologists relied on autopsy findings to reach diagnoses. Among the 14 living patients, neurologists used cognitive assessments, concluding that all had well-documented conditions such as Alzheimer’s, Parkinson’s, cancer, traumatic brain injury, and post-concussion syndrome.
Dr. Anthony Lang, a neurologist at the Krembil Brain Institute within the University Health Network, remarked, “I was confident that there was a clear explanation for 100% of the cases.”
Nevertheless, some medical professionals are concerned that this evidence may not quell speculation about an underlying unknown cause, which many patients and their families continue to believe in.
According to the authors of the study, 52 individuals connected to the New Brunswick cluster declined a second opinion, and another 42 individuals were unreachable. This lack of response has been attributed to the spread of misinformation through both traditional and social media, undermining trust in healthcare systems.
“These instances reflect misdiagnosis, leading to misinformation. Unfortunately, the doctors involved persist in convincing patients and their families that they have a mysterious illness,” Lang emphasized.
Marello expressed skepticism regarding the study’s methods and conclusions in a statement, saying, “I hold serious reservations about the validity of the research and have numerous questions regarding its methodology and content. We believe that our patients, families, and communities share these significant concerns.”
Dr. Valerie Sim, an associate professor of neurology at the University of Alberta and not part of the study, stated there is no evidence linking the patients’ illnesses. She noted that the description of the cases is too broad and could apply to multiple conditions.
“Sadly, the unifying factor is that all these patients saw the same neurologist,” Sim pointed out. “Patients evaluated by different specialists have been diagnosed with known conditions that aren’t mysterious.”
James Mastorianni, a professor of neurology at the University of Chicago, highlighted that while not included in the study, it underscores the importance of seeking second opinions from experts in the field.
Ongoing Investigation
The Mystery Disease Theory gained traction in 2021 when Canadian health officials launched an investigation based on Marello’s observations. However, even after the inquiry determined that most patients had identifiable conditions, skepticism remained among families. In November, Susan Holt, the Prime Minister of New Brunswick, called for a scientific review of the “mysterious brain diseases.”
“The residents of New Brunswick deserve answers,” Holt stated in a public statement last year. “We must understand the source of our illnesses.”
Some advocates for patients suspect that environmental factors may be contributing to the illnesses, noting that blood tests have detected heavy metals, pesticides, and rare antibodies, warranting further investigation.
“None of our patients received an alternative diagnosis,” said Kat Lantine, an advocate in New Brunswick. “What led to their neurodegenerative disease?”
Dr. Yves Legger, New Brunswick’s chief medical officer of health, stated in a recent statement that the new study “does not alter our commitment to thoroughly investigating cases of undiagnosed neurological diseases in New Brunswick.”
His office has received 222 case reports in connection with this cluster.
Marello mentioned, “We have evaluated over 500 patients in this cluster and provided substantial evidence regarding environmental exposures, as well as rare autoimmune markers present in several cases.”
However, Lang cautioned that detecting substances in the blood or urine does not necessarily imply they are the cause of neurological symptoms.
“You cannot take a scattershot approach, where you find something and assert that it’s relevant to the health issue,” he explained.
Challenges in Diagnosing Neurological Problems
Neurologists not involved with the New Brunswick situation highlight several challenges that continue to spur discussions among advocates, doctors, and government officials about the illness’s origins.
For starters, they note that accurate diagnoses can take time. Some conditions highlighted in the study exhibit complex symptom profiles, like Alzheimer’s.
“We need a comprehensive history from the family along with a timeline to identify if someone is developing dementia. There may be early signs of confusion evident in neurological tests,” indicated Dr. Kimberly O’Neal, a neurologist at the Health Multiple Sclerosis Comprehensive Care Center at NYU Langone.
Rapidly progressing dementia was one of the key symptoms observed in New Brunswick patients. However, families sometimes overlooked early indicators of neurodegeneration, which made it appear as though dementia appeared suddenly, according to Mastorianni.
When severe symptoms manifest, patients and their families often seek answers and can be hesitant to abandon their initial diagnoses, Sim noted.
“This phenomenon is common in medicine. Patients often become attached to a diagnosis or a group of conditions,” Sim remarked. “That is evidently the case here.”
Misdiagnosis can be “truly tragic,” as it may prevent patients from receiving effective treatment and proper care.
