Cancer sometimes triggers sudden memory loss — now we might know why

A colorful 3D illustration of two virus-like particles, depicted in green, light blue and dark blue.

Cancer can sometimes trigger an off-the-rails immune response that harms nerve cells, rapidly leading to thinking problems and memory loss — but until now, scientists weren't sure what caused this rare complication.

This disorder is a type of paraneoplastic neurological syndrome (PNS), and researchers already knew it stems from the immune system's reaction to a tumor rather than the tumor itself. It occurs when a tumor sets off an autoimmune response that targets the brain and spinal cord.