What causes stenosis?

peekaboo · Post by **peekaboo** » Thu Jul 30, 2009 7:57 am

The universe must have heard you rant

Post by **jimmylegs** » Sat Aug 01, 2009 7:33 am

arteries not veins, but possibly related?

Association between Plasma Homocysteine Concentrations and Extracranial Carotid-Artery Stenosis
http://content.nejm.org/cgi/content/abstract/332/5/286
High plasma homocysteine concentrations and low concentrations of folate and vitamin B6, through their role in homocysteine metabolism, are associated with an increased risk of extracranial carotid-artery stenosis in the elderly.

Relationship between Plasma Homocysteine, Vitamin Status and Extracranial Carotid-Artery Stenosis in the Framingham Study Population
http://jn.nutrition.org/cgi/content/abs ... uppl/1258S
Prevalence of high homocysteine (> 14 µmol/l) was 29.3% in this cohort, and inadequate plasma concentrations of one or more B vitamins appear to contribute to 67% of the cases of high homocysteine. Prevalence of stenosis 25% was 43% in men and 34% in women with an odds ratio of 2.0 for individuals in the highest homocysteine quartile (14.4 µmol/l) compared with those in the lowest quartile (9.1 µmol/l), after adjustment for sex, age, high density lipoprotein cholesterol, systolic blood pressure and cigarette smoking (Ptrend < 0.001). Plasma concentrations of folate and pyridoxal-5'-phosphate and folate intake were inversely associated with extracranial carotid stenosis after adjustment for age, sex and other risk factors.

Post by **jimmylegs** » Sat Aug 01, 2009 7:47 am

just posted this under the geographic distribution topic:

possible tie in? i just stumbled across a link between stenosis formation and increased metalloproteinase activity.. a while back nick had posted on my ortho regimen about vitamin d3 insufficiency being also related to higher mmp and bbb interference.

Abnormal Expression of Matrix Metalloproteinases and Tissue Inhibitors of Metalloproteinases in Brain Arteriovenous Malformations
http://stroke.ahajournals.org/cgi/conte ... a;34/4/925
Excessive degradation of the vascular matrix by matrix metalloproteinases (MMPs) can lead to structural instability of vessels. In this study we examined the expression of MMPs and tissue inhibitors of metalloproteinases (TIMPs) in brain arteriovenous malformations (BAVMs).
We found increased levels of MMP-9 and TIMPs in BAVMs. Abnormal balance of MMP-9 and TIMPs may contribute to vascular instability of BAVMs.

Post by **jimmylegs** » Fri Aug 14, 2009 12:58 pm

a plug for the b vitamins in preventing stenoses...

Association between plasma homocysteine concentrations and extracranial carotid-artery stenosis.

BACKGROUND. Epidemiologic studies have identified hyperhomocysteinemia as a possible risk factor for atherosclerosis... We performed a cross-sectional study of 1041 elderly subjects (418 men and 623 women; age range, 67 to 96 years) from the Framingham Heart Study. We examined the relation between the maximal degree of stenosis of the extracranial carotid arteries (as assessed by ultrasonography) and plasma homocysteine concentrations, as well as plasma concentrations and intakes of vitamins involved in homocysteine metabolism, including folate, vitamin B12, and vitamin B6. ...The prevalence of carotid stenosis of > or = 25 percent was 43 percent in the men and 34 percent in the women... Plasma concentrations of folate and pyridoxal-5'-phosphate (the coenzyme form of vitamin B6) and the level of folate intake were inversely associated with carotid-artery stenosis after adjustment for age, sex, and other risk factors. CONCLUSIONS. High plasma homocysteine concentrations and low concentrations of folate and vitamin B6, through their role in homocysteine metabolism, are associated with an increased risk of extracranial carotid-artery stenosis in the elderly.

Sharon · Post by **Sharon** » Fri Aug 14, 2009 1:54 pm

JL

I do not believe the carotid artery stenosis is the same type of stenosis being found in the jugular and asygous vein.

The narrowing is usually caused by plaque in a blood vessel. Plaque forms when cholesterol, fat and other substances build up in the inner lining of an artery. This process is called atherosclerosis.

Found here:http://www.americanheart.org/presenter. ... ifier=4497

I doubt the B vitamins would prevent the veinous stenosis. Interesting study though, especially for me who is the more "mature" on this forum and I should be more aware of my artery health.
Sharon

Post by **jimmylegs** » Fri Aug 14, 2009 1:59 pm

heya shar, i have no idea if they are the same. there's just more research on these kind of stenoses and how they form.

here is a neat carotid stenosis graphic:

another image (don't know if it likes png extensions but i'll try anyway):
http://www.vabrainandspine.com/EdVascular.htm this is possibly the lamest web site i've ever seen but at least they have this image..

who's got a good shot of a jugular or azygous stenosis? google image is not my friend in this case

i'd like to know what the difference(s) between these stenoses and other stenoses are, for sure.

as far as the carotid example goes, my understanding of why cholesterol etc builds up on artery walls in atherosclerosis, is at least in some part, a protective response to an injury of some kind to the wall itself, such as in high blood pressure. that's all i got for now

cheerleader · Post by **cheerleader** » Fri Aug 14, 2009 2:51 pm

Dr. Byung B. Lee will be speaking and presenting research on embriology and venous malformations of the extracranial pathways at the Bologna conference. This may very well be a congenital birth defect- like club feet, cleft palettes and crimped veins.

I'll report back,,,
cheer

Post by **jimmylegs** » Fri Aug 14, 2009 4:55 pm

could be - at this point, i'm having trouble finding much research on the etiology of cerebrospinal venous stenoses... i'm inclined to think there will be a few different answers as to how these things develop - or don't - depending on the patient. it will be interesting to read more over time.

Sharon · Post by **Sharon** » Fri Aug 14, 2009 6:16 pm

JL - I have a manual from a vascular convention held here in Denver this summer with hundreds of abstracts --not one is about cerebrospinal venous stenoses.
I agree with you, as this model is researched we will begin to have theories and eventually answers as to how they develop.

Sharon

cheerleader · Post by **cheerleader** » Fri Aug 14, 2009 7:37 pm

It's been mostly studies as jugular foramen stenosis in children who have Crouzon's or intracranial hypertension- due to a congenital narrowing of the skull which crimps the IJVs and causes relux....but it's usually caught in this instance in the kids because of hydrocephalus, plus Crouzon's patients have other physical signs. MSers have a less obvious malformation...Byong is looking at it as a congenital extracranial venous malformation.
http://www.ajnr.org/cgi/content/full/24/1/45

cheer

Post by **jimmylegs** » Sat Aug 15, 2009 5:08 am

hmm yes, the structural skeletal stenosis of the jugular opening in a child's skull certainly does sound congenital. i am skeptical of all venous stenoses throughout the body being congenital in nature... i guess we'll have to wait and see if the kind seen in ms patients is.

Post by **jimmylegs** » Sat Aug 15, 2009 4:55 pm

i put stenosis and zinc in google, and lo and behold up pops hydrocephalus which i never heard of before today lol!

"hydrocephalus is frequently found associated with in utero zinc deficiency, and the severity of many accompanying histological changes seen in the developing neuropil seem to be directly related to the severity of the hydrocephalic condition... this disordered local growth, coupled with abnormal spatial relationships in the walls of the mesencephalon, which appears to result from lack of pontine flexion, could in turn contribute to constriction, stenosis..."

Ernst · Post by **Ernst** » Sat Sep 12, 2009 10:21 am

So, my original question "what causes stenosis?" is still in my mind. Now, after Bologna - are we wiser about this?

skydog · Post by **skydog** » Sat Sep 12, 2009 11:12 am

Thanks JL, In my case without further researching the zinc connection right now. It truly seems odd that for me since being born from a extremely health conscious mother and then living a very healthy childhood that this would tie in to my case. What ever has changed that has caused stenosis in me seems to have happened much latter in life. Most recently in the last two months! As you know both the right and left have nearly collapsed low down in the neck where most of the stenosis in other patients has been found. The first MRV showed almost perfect jugulars and aside from the sharp pig tail looped right and sharp bend in the left both way up in the sinus area no major stenosis. Now opening the restriction in the right jug gave me a taste of what it means to have free flowing jugs. The first two weeks post surgery were great, now I have slipped back to how I felt prior the stenting two months ago. Ernst I am not sure how much wiser we are at this point, but we now have a collection of the best Dr.'s in the world searching for the answers. We will get there from here. Cheers, Mark

Rokkit · Post by **Rokkit** » Sat Sep 12, 2009 4:05 pm

Ernst,

When the occlusion is a stenosis (not a crimping, smashing, or arachnoid cyst, etc.) it seems that so far no one has posited an explanation other than it being congenital. I'm pretty sure it's been mentioned that Dr Dake thinks the stenosis is probably congenital, and the Dr from Georgetown said so at Bologna.

90% (so far) of Zamboni's children with venous abnormalities have developed MS. That doesn't make congenital the only possible explanation, but I'm just thinking since the information we have so far points congenital and there's no information pointing any other way, then that seems the most likely.

There will no doubt be a lot of research in that direction in the post-Bologna era.

Rokkit