Updated on October 25, 2024
Multiple sclerosis, or MS, is a disease of the central nervous system characterized by damaged areas of the brain, called lesions or plaques. In this video, Vincent Macaluso, MD, explains the role of lesions in MS and how they can range in severity.
Medically reviewed in December 2019.
Transcript
[MUSIC PLAYING] I have relapsing remitting multiple sclerosis, and my doctors often reference lesions.
What exactly are lesions, and how do they affect my relapsing remitting multiple sclerosis? Good question, Alexis.
To understand the role the lesions play in relapsing remitting MS, we need a basic understanding of how MS works. Our nerves are kind of set up like computers, hooked up
to modems. The cell body of the nerve is the computer. And that comes up with a message that gets sent down the axon, which is wrapped by insulation
and then goes to the end. That sends off the message to other nerves or muscles or organs. The MS attacks the insulation around our axon.
And by doing that, the message can't get from the computer out to other nerves in the rest of your body. If you myelinate one nerve, you wouldn't notice it
because nerves are only 25 microns big. But when we speak of the lesions that we see on MRI, those are macroscopic, meaning we see them with our naked eyes.
Therefore, if you see a lesion, that means that thousands and thousands of nerves have already been demyelinated. It's fair to assume that the more lesions you have,
the more disability you're going to have. The thing is that the disability isn't always something you can see. Almost half of our brain is our frontal lobes.
And that's what controls our initiative concentration, emotional control, sexual functioning, urinary control, and general behavior.
It's harder to tell changes in that versus seeing somebody has a weak leg or trouble with coordination in one of their arms.
Even if people don't see anything or if the person doesn't see anything, the disease is still going on in our brains and spinal cords all the time at some degree.
So when demyelination is actively going on, that's the relapsing part. But then after we come out of the relapsing
part and everything's quiet, that's the remitting part. And hopefully we have more remitting parts than we do relapsing parts.
