Six years ago, a Canadian neurologist in New Brunswick noticed unusual symptoms in a group of patients, including hallucinations, spasms, rapid memory loss, and the sensation of bugs under their skin. Dr. Alier Marrero found that their symptoms didn’t align with any known diagnosis, making the cases a mystery. Subsequent reviews by neurologists identified clear conditions like Alzheimer’s, Parkinson’s, and cancer among the patients. A recent study published in JAMA Neurology supports these findings, suggesting the likelihood of a mystery disease in this cluster is extremely low.
The study involved evaluating 25 patients from New Brunswick, with autopsies used to determine the illnesses of deceased patients. Living patients underwent cognitive assessments and other tests, leading to diagnoses like Alzheimer’s, Parkinson’s, cancer, traumatic brain injuries, or post-concussion symptoms. Dr. Anthony Lang, a neurologist involved in the study, stated that they were able to explain all cases conclusively.
Despite these findings, concerns persist that the cases may have an unknown origin, a belief held by some patients and families. Many individuals from the cluster declined second opinions or didn’t respond to outreach efforts, possibly due to mistrust in healthcare institutions and misinformation on various media platforms.
While Marrero disagreed with the study’s conclusions, other experts like Dr. Valerie Sim emphasized the lack of evidence linking the patients’ illnesses. Dr. Sim pointed out that patients evaluated by different neurologists received known diagnoses, not mystery illnesses. The importance of seeking second opinions from experts in the field was underscored by Dr. James Mastrianni, indicating its value in confirming diagnoses.
In response to ongoing skepticism and calls for further investigation, Canadian health authorities initiated a review following Marrero’s reports in 2021. Despite most cases being linked to known conditions, some families remained doubtful. New Brunswick’s premier requested a scientific review of the situation, reflecting the continued uncertainty surrounding the mystery brain disease.
“We deserve to know what is causing our sickness,” stated Holt in a press release last year. Some patient advocates now suspect that environmental exposures are triggering these illnesses, citing the presence of heavy metals, pesticides, and rare antibodies in blood and urine tests of patients that call for further investigation. “The focus has always been on identifying the trigger for this neurodegenerative disease, not on alternative diagnoses,” explained advocate Kat Lanteigne from New Brunswick. Dr. Yves Léger, the chief medical officer of health in New Brunswick, emphasized that despite a new study, his office remains committed to completing its investigation into cases of undiagnosed neurological illness in the region. The office has received reports of 222 cases within the cluster.
Marrero reported evaluating over 500 patients in this cluster, providing compelling evidence of environmental exposure and rare autoimmune markers in many. However, Lang cautioned against assuming a direct link between these substances in blood or urine and the patients’ neurological symptoms. The challenge of diagnosing neurological issues is complex, as accurate diagnoses can be time-consuming. Additionally, conditions like Alzheimer’s can present with intricate symptoms, making it challenging to pinpoint the cause of the illnesses.
Neurologists not involved in the New Brunswick cases highlighted that the diagnostic process requires a cohesive narrative from the family and a timeline to comprehend the development of conditions such as dementia. Early signs of neurodegeneration can be missed, leading to a perception that dementia onset was sudden. Patients and families often cling to initial diagnoses, seeking answers and care while potentially missing out on appropriate treatments.
