Multiple Sclerosis Plaques
Multiple sclerosis (MS) plaques are areas of inflammation and damage affecting myelin, the protective coating surrounding nerve fibers in the brain and spinal cord. These lesions can disrupt the transmission of nerve signals and are a hallmark imaging feature of multiple sclerosis. Plaques vary in size, number, and location, and their appearance on MRI plays an important role in diagnosing MS, monitoring disease activity, and guiding treatment decisions.
What is it?
Multiple sclerosis plaques develop when the immune system mistakenly attacks myelin, the protective sheath surrounding nerve fibers in the central nervous system. This inflammatory process creates areas of damage that commonly appear as bright spots on certain MRI sequences.
MS plaques often occur in characteristic locations including the white matter near the ventricles, the corpus callosum, the brainstem, the cerebellum, and the spinal cord. The location of lesions frequently correlates with neurological symptoms experienced by the patient.
MRI is the preferred imaging test for evaluating multiple sclerosis because it can detect lesions even before significant symptoms develop. Contrast-enhanced MRI may help identify active inflammatory plaques, while non-enhancing lesions may represent older or inactive areas of demyelination. Brain and spinal cord MRI together provide a more complete assessment of disease burden and activity.
Important to Know
Not every white matter abnormality seen on MRI represents multiple sclerosis. Similar imaging findings may occur with migraines, small vessel ischemic disease, infections, autoimmune disorders, or aging-related changes. MRI findings must therefore be interpreted alongside symptoms, neurological examination, and, in some cases, spinal fluid testing or additional laboratory studies.
Once MS is diagnosed, follow-up MRI imaging is commonly used to monitor for new lesions, assess treatment response, and evaluate disease progression over time.
Red flag symptoms include sudden vision loss, severe weakness, loss of bladder or bowel control, difficulty speaking, or rapidly worsening neurological symptoms. These warrant prompt medical evaluation.