FREDERICTON -- New Brunswick Public Health is investigating a fatal brain disease they don't have a name for.

It looks like Creutzfeldt-Jakob disease (CJD), which can cause memory loss, sudden movements and vision problems, but a neurologist says it's more likely a new syndrome altogether.

"We don't know what is causing it, so we keep our minds open to possibilities," said Dr. Alier Marrero, a neurologist with Vitalité Health Network. "We cannot say this is Creutzfeldt-Jakob disease. It doesn't look that way."

Over the last five years, 35 cases have been confirmed as the unknown neurological disease and eight are suspected. Five people have died.

The province's chief medical officer of health say they have "a lot of work to do" to determine why the disease has appeared – and if it's environmental.

"It most likely is a new disease," said Dr. Jennifer Russell. "We haven't seen this anywhere else and so it's of unknown etiology but the symptoms are very like CJD."

In 2019, 700 patients at the Moncton Hospital had to be contacted after two suspected cases of Creutzfeldt-Jakob disease were identified in patients who had cataract surgery at the Moncton Hospital.

Health officials haven't confirmed if these two patients are considered part of this cluster.

According to a March 5 memo from Dr. Cristin Muecke, N.B. Deputy Chief Medical Officer of Health, the median age for the cases found in N.B. is 59 years – but some are in their early fifties.

Dr. Marrero is studying the disease and says patients have presented with unexplained pain, loss of memory, involuntary movement, blurry vision and hallucinations.

He says it's been very difficult on patients and their families.

"Sometimes the patients, when they are diagnosed, they don't have the capacity to really understand this is happening," he said. "Obviously their families do. And many of the patients initially do as well. So it's very hard."

He added it's also difficult not to be able to provide families with a name, or a definitive diagnosis.

The cases have been sent to the Creutzfeldt-Jakob disease surveillance system.

In an e-mail, a spokesperson for the Public Health Agency of Canada (PHAC) said its Creutzfeldt-Jakob Disease Surveillance System has received case referrals from the province of New Brunswick.

"PHAC is aware of the situation and has been collaborating with physicians and public health officials in New Brunswick since January 2021 to conduct their public health investigation by providing diagnostic testing services and epidemiologic expertise," wrote spokesperson Anna Maddison. "Please note that New Brunswick is leading the ongoing investigation, with collaboration from the Public Health Agency of Canada."

It's rare for any Maritime province to see a case of CJD. Nova Scotia and New Brunswick usually see one case of CJD a year.

The disease is degenerative and can cause a fatal form of dementia.

Health officials across New Brunswick are being asked to watch for patients who present with symptoms similar to CJD.