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Finding challenges accepted view of MS: unexpectedly, damaged nerve fibers survive.
February 6, 2013 by David Tenenbaum

(Medical Xpress)—Multiple sclerosis, a brain disease that affects over 400,000 Americans, causes movement difficulties and many neurologic symptoms. MS has two key elements: The nerves that direct muscular movement lose their electrical insulation (the myelin sheath) and cannot transmit signals as effectively. And many of the long nerve fibers, called axons, degenerate.

Many scientists believe that axons are doomed once they lose the insulation, but a new study by graduate student Chelsey Smith and former undergraduate Elizabeth Cooksey in the Journal of Neuroscience shows axons can survive for long periods in rats even after losing myelin.

"This was the first study to demonstrate long-term axon survival after myelin deterioration," says senior author Ian Duncan, a professor in the School of Veterinary Medicine at the University of Wisconsin-Madison.

The mutant rats in the experiment have substantial myelin at first, but by eight weeks the essential myelin insulation is lost. "It was surprising," says Duncan, an expert in MS pathology. "Nine months is a relatively long period in a rat's lifetime, and there wasn't a loss of axons, so the assumption that axons must automatically die without myelin seems incorrect."

...to read the rest click here.

Yes, it's rats, not humans---but it's an important discovery. Thanks for the post, Curious. Axons can survive a loss of myelin, but they cannot survive long without adequate perfusion.
Which is why we need gray matter research and biomarkers for MS progression. Looking at the white matter isn't giving us the full picture of disease progression.
http://archneur.jamanetwork.com/article ... eid=793392

...and this is why someone with over 20 white matter lesions and no gray matter atrophy, like my husband, can mountain bike and downhill ski. And why our friend with one white matter lesion, but severe gray matter atrophy, is no longer mobile.
Here's more from Dr. Zivadinov on why it's time to change MS pathogenesis studies and look at gray matter.
http://www.thisisms.com/forum/general-d ... 18-15.html
cheer

cheerleader wrote:...and this is why someone with over 20 white matter lesions and no gray matter atrophy, like my husband, can mountain bike and downhill ski. And why our friend with one white matter lesion, but severe gray matter atrophy, is no longer mobile.
cheer

MS is a very complex disease, there may be as many reasons why people have MS as there are people who have MS. The above statement from cheerleader may be somewhat misleading, although adequate perfusion as she points out is very important to brain health.

I have had MS for over 30 years now, I have more than 20 white matter lesions in my brain, and many in my brain stem and spinal cord. My MS has been confirmed by my primary neurologist, the UCSF MS clinic, and by the Neurology Center at Stanford. There is little doubt that I have MS.

I last snow skied in 2005 and stopped running in 1997, I no longer backpack or hike in the mountains, and no longer swim laps. I now use Ampyra to promote nervous signal transmission across demyelinated lesions to help with walking and lower body issues. My MS has continued to progress slowly across all this time.

I have no CNS atrophy in my brain or spinal cord.

My point is that there are many people who have had MS for MANY years and can still walk and manage there lives successfully. There is no proven means to correlate lesions to physical disability or specific symptoms.

May cheerleader's husband continue to walk and ski for many years, hopefully indefinitely. But the fact that he is still doing so less than 10 years after diagnosis is not in itself remarkable, or proof of any treatment related to MS.

--Tracy