A 64-year-old woman kept having sudden, temporary brain symptoms, but she had no typical risk factors like high blood pressure or diabetes. Doctors took a close look at her brain MRI and found a thin, bright line along the brain's surface, known as the ribbon sign. This sign can point to a rare condition called neuronal intranuclear inclusion disease (NIID). They also saw a narrowed artery in her brain, but that was likely a separate issue.
To confirm the diagnosis, doctors did a skin biopsy. Under an electron microscope, they saw the tiny, telltale inclusions inside cells that are the hallmark of NIID. A genetic test for the known NIID mutation was negative, so the biopsy was key.
This is just one person, so we can't generalize from it. But it shows how important it is for doctors to recognize the ribbon sign on an MRI, even if a patient also has a common problem like a narrowed brain artery. When genetic tests don't give a clear answer, a targeted tissue biopsy can be the next best step.