FREDERICTON — New Brunswick health officials will begin analyzing hundreds of cases involving a mystery brain disease that has baffled experts for years, the province's chief medical officer said Thursday.
Dr. Yves Léger told reporters that his office will review 222 files with the Public Health Agency of Canada into an "undiagnosed neurological illness" affecting residents in the province. He said he expects the cases to be analyzed and scientifically reviewed by the end of May.
Léger's update on the government's investigation follows years of complaints from patients who accused the province of being too quick to dismiss their concerns.
In 2021, the provincial government under the Progressive Conservatives investigated 48 patients with neurological symptoms of unknown origin, such as bursts of intense pain, muscle spasms, memory problems, balance issues, and behavioural changes. A year later, the government said it found no evidence of a common illness.
Health officials in the province say more than 400 people, mostly in New Brunswick, have reported symptoms of the mystery illness. And the Liberals promised during last year's election campaign to reopen the investigation.
Léger said his office had collected "enough complete and verified patient data" to begin reviewing the 222 files.
Most of the cases were brought to the attention of authorities by a single neurologist — Dr. Alier Marrero — who had suggested the illness was caused by environmental factors such as elevated levels of pesticides.
Léger said the province's new investigation aims to understand if environmental factors are affecting patients.
Sixteen of the 222 files under review involve people living in six other provinces — Nova Scotia, Prince Edward Island, Newfoundland and Labrador, Quebec, Ontario and Alberta. All have "some sort" of connection to New Brunswick, he said, without giving details.
Sarah Nesbitt, 42, said she has been suffering neurological symptoms for about five years. She said she worries the new investigation will end like the first one — with few clear answers. But she said she is happy that the government is studying whether the environment has played a role in her illness.
Nesbitt's partner, Melissa Hawkes, started showing symptoms in 2021 but has been diagnosed with a tumour near her pituitary gland. Hawkes, 28, was scheduled for an MRI on Thursday to get a better idea of her condition, Nesbitt said.
In a separate news conference Thursday, Premier Susan Holt said an all-hands-on-deck approach is needed to help patients suffering from the mystery illness. "The bottom line is it needs to move faster," she said.
"I'm frustrated as well that things aren't going as quickly as I'd like to see it go … but we have an investigation plan. The work is being done. It's been done over many weeks, even months now, and there will be data coming out."
April Merritt's husband, Philip, has been battling neurological symptoms of unknown origin since 2002. His symptoms include severe headaches, high blood pressure, depression, and short-term memory loss, Merritt said in an interview Thursday. The couple live in Blackville, N.B., about 100 kilometres northeast of Fredericton.
Merritt said her 48-year-old husband was exposed to pesticides as a child near his home in Miramichi, N.B. After multiple misdiagnoses, including bone cancer, Philip Merritt's condition deteriorated, leading to bed confinement and severe mobility issues.
April Merritt said it was in 2020 that Marrero diagnosed her husband as having the brain disease. More than 20 years after his symptoms first began, she said, "he has trouble with his walking, trouble thinking, concentrating, littlest tasks he can't really do anymore."
Merritt said it felt bittersweet to listen to health officials update their progress in the investigation.
"It makes me happy and sad. I'm happy that there's people not as sick as my husband who may get help or help the future generations," she said. "But it's also hard having a disease that you don't know what your next step is."
She said her husband has donated his body to be studied after his death. "He wants to help other people. That's his goal."
This report by The Canadian Press was first published March 27, 2025.
Hina Alam, The Canadian Press
