One of the symptoms reported is thinking your loved one is an imposter.
There are currently 48 cases of a mysterious brain disease in New Brunswick that are under investigation and the condition is being called a "neurological syndrome of unknown cause (NSUC)."
According to the Government of New Brunswick, doctors in the province have been reporting people with "an unusual combination of neurological symptoms" since early in 2020. While an extensive investigation has taken place and continues still, they can't figure out a diagnosis.
There are 48 cases under investigation and six deaths, though they can't be 100% sure that this syndrome was the exact cause of death.
Symptoms include memory problems, muscle spasms, difficulty walking, hallucinations, significant weight loss, and the list continues.
Furthermore, BBC News has reported that some patients have experienced "Capgras delusion," where someone believe that one of their loved ones has been replaced with an imposter.