Healing of lesions

[shoshin]

Quix or anyone,

You said in your post on relapses that "Over time, the symptoms that a person deals with on an ongoing basis will change as some lesions in the CNS heal and others appear." I was just wondering about the healing of lesions.

When I had my follow-up MRI, the neuro said he only needed the brain done because if I had new lesions in the spinal cord I would know (they would be symptomatic), but he also mentioned that I could have an MRI of the spine to see if any of the lesions were healing.

Does that happen often? After a certain amount of time, are the lesions not likely to heal anymore? So if the symptoms have been there for years, does that mean they're not going to go away?

Thanks!

[shoshin]

Quix: Thank you very much for your explanation. I thought there probably wasn't a definitive answer. There seem to be an awful lot of things that we'd like to know about MS, but we don't know :(

Heather: Yes, I learn a tremendous amount from this forum and from everyone, including you. Thank you for your dedication to this site.

[Heather3418]

As always, Quix's explanation is perfect.  There isn't a thing I can add and have actually learned something new myself.  Even an old veteran MS'er like myself.

Heather

[Quixotic1]

I really can't answer your question with any certainty.  In my reading I have gotten the impression that healing can occur progressively or in stages over many months to even many years.  It depends on how much damage is done to the cell that maintains the integrity of the nerve fiber (axon) coming off of it.  This cell is called an Oligodendrocyte.  If the cell/nerve complex remains viable then theoretically the healing could occur at any time.  I have not heard anything about a certain length of time.  It is more a factor of extent of damage.

But, if there is enough damage, the cell/fiber reaches a point of axonal death and degeneration.  And there's no coming back from that.  The areas of axonal death/degeneration form the T1 Black Holes that we have talked about before.

Also, relatively mild attacks on the myelin (the white, fatty sheath insulating the nerve fiber) may heal within a few weeks of the attack.  This is often the case for the very short relapses.  It appears though, that, while the "healed" areas may disappear from the MRI, the function of the myelin does not return to perfect form.  The nerve fiber still may have some delay in conducting it's signal.  That is why old symptoms may suddenly pop back up with a rise in body temperature.  

Damaged myelin, even though it is "repaired," is never as good as before the immune attack.  I think of it like the "old football injury."  The knee usually feels okay until the barometer falls just before a storm and it acts up with pain again.

Quix