Someone tell me this in plain English.

Lori,

“Onion bulb formation” is the result of repeated demyelination of a nerve segement. Schwaan cells attempt to remyelinate the segment, but usually complete this process thinly due to additional attacks. From my reading, I have come to understand (in chronic variants) this type demyelinating occurs from compliment-activated antibodies, otherwise known as the “humoral immune defense”.

Your doctor also implies that motor nerves and autonomic nerves are affected in addition to sensory nerves.

In my last post to Aimee in “New test results”, I included a link for med students (good pictures and explaintions) for pheripheral nerve diseases that includes gbs/cidp/cmt. I found it fairly easy to understand.

I wish by explaining (or understanding) these terms it would be possible to make things better. Sometimes I think if I just keep looking . . .I’ll find that magic bullet.

Best wishes for Dell

cd

Lori, in plain english, Dell has cidp. cidpusa dot org has a good explanation of this type of dx with pics. Give Dell a Big Hug for me.

Hi, Lori.

[QUOTE=Dells mom]
“onion bulb formation and severe demyelination associated with inflammation in a diffused fashion affecting motor (autonomic and striatal) and sensory nerves.”[/QUOTE]

Demyelination means that the myelin sheaths, the fatty insulation on the nerves, is damaged during relapses. In Dell’s case, the the demyelination is severe, is spread over a wide area (diffused), and is associated with inflammation–is associated with an immune reaction. This affects the motor nerves which run from the brain (striatal nerves) controling voluntary movement (arms, legs, etc.) and those controling autonomic function (heartbeat, breathing, etc.), as well as the sensory nerves running back to the brain which control sensation.

When the nerves remyelinate, they don’t grow back as they were, but tend, as CD said, to grow back in thin layers. With each remission (each time the attack ends and allows for regrowth), layer regrows over layer, forming something comparable to an onion. That onion bulb appearance is very indicative of demyelinating neuropathies.

Best wishes in the battle,

Deb
London

Lori,

It makes me so sad when young children/young adults are faced with such complex issues as this – I sympathize with all that you and Dell are going through.

I also want to provide you with information that, I believe, will make a huge difference in the lives of our children in the not-too-distant future.

Currently I am researching the specific mode of action of “fas function”. This is quite a technical subject, but if you have a rheumatologist or immunologist, they may be familiar with the subject. I downloaded a pdf research report discussing fas function in relation to cidp from the Journal of Peripheral Nervous System (2006).

Quote: “fas is involved in switching-off the immune response.”

—here’s my understanding of this process—

It is a receptor on t-cells that is related to the immunoglobulin family, which might explain in part, why/how ivig works. When functioning correctly, fas determines that “invading antigens” have cleared the system, and then “turns off” the auto-immune reply by causing apoptosis (cell death) in cytolitic t-cells. This might also help to explain why, in some cases ivig does not help as much as others. For example in Norb’s case, with predominately b-cells causing the damage, fas reduces t-cells (which signal b-cells). This suggests that b-cells are only indirectly affected by this particular pathway. I have seen where there are anti-fas mabs now used in animal investigations, and wouldn’t be surprised to hear of human mabs in the near future.

Already, I got into more technical info than you probably wanted – but I wanted to throw this out in case you found it interesting enough to discuss with your son’s physician. I can send you a copy of the article if you’d like.

Deb,

Thanks for making sense of the murky explaination I offered. Sometimes I have a hard time getting my thoughts on paper – you did a wonderful job. Feel free to clarify this attempt as I am still learning lots.

Best wishes to all
cd

Found link to article here:

[url]http://www.blackwell-synergy.com/doi/full/10.1111/j.1085-9489.2006.00063.x?cookieSet=1[/url]

cd