Cause of 8 New Brunswick 'mystery' brain disease deaths identified by pathologist

A neuropathologist who examined the deaths of eight people in New Brunswick initially described as having a mysterious neurological disease says the deaths were actually due to known diseases.

A summary of the study led by Dr. Gerard Jansen of the University of Ottawa, posted this month on the Canadian Association of Neuropathologists website, says the original cases were "misclassified clinical diagnoses."

In March, New Brunswick health officials alerted the province’s doctors, nurses and pharmacists about a cluster of residents with an unknown and potentially new neurological syndrome with symptoms similar to those of Creutzfeldt−Jakob disease.

Jansen’s study indicates that those who died had diseases that included known neurodegenerative diseases and cancers.

He identified health issues that included Alzheimer’s disease, metastatic cancer, frontotemporal degeneration, Lewy body disease and vascular disease.

The abstract notes the cluster had been reported at around 50 cases, and eight people in that group have died since 2019. The Canadian Association of Neuropathologists declined a request to provide access to the full report.

Jansen and his co−authors say in the abstract they hope the findings are useful to a provincial committee set up this June to review the clinical and epidemiological data of the patients in the cluster.

Jansen has been involved in clinical surveillance of Creutzfeldt−Jakob disease, one of a group of rare progressive neurodegenerative disorders known as prion diseases, for over 30 years.

"During that time he has seen all types of prion diseases passing by ... but also many look−alike neurological diseases," says the abstract.

Steve Ellis, whose father had been identified as having the mysterious neurological disease, said news of Jansen’s findings came out of the blue.

"For the last two−and−a−half years my father has been told what he doesn’t have by two neurologists who are on the oversight committee in New Brunswick. If he has something that is a known disease, why hasn’t he been diagnosed yet?" Ellis asked in an interview Tuesday evening.

"There are too many questions coming from this very vague report, which the government of New Brunswick didn’t tell us was coming," he said. "It doesn’t answer the questions of those who are still living and why they’re sick and why they don’t have a diagnosis."

Ellis’s father, Roger Ellis, who is being cared for at a seniors home in Bathurst, turned 64 on Tuesday.

Ellis said he had spoken earlier in the day with family members of other patients suspected of having the mysterious neurological disease, and they were very upset.

The New Brunswick government launched a website in April to update the public on what it called a "neurological syndrome of unknown cause." Health officials have a news conference scheduled Wednesday to discuss the status of their investigation.