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Source of spinal cord damage

Posted: Thu Jul 07, 2011 5:43 am
by gibbledygook
It looks as though the epidural space is drained by the neck veins, as well as by the azygous and others.
This might explain why jugular constrictions damage the spinal cord, although I'm not sure if the jugular is a "deep vein" of the neck.
Reg Anesth Pain Med. 2011 Mar-Apr;36(2):134-9.

Direct connections between the spinal epidural space and the venous circulation in humans.

Buffington CW, Nichols L, Moran PL, Blix EU.


Source

Department of Anesthesiology, University of Pittsburgh, Pittsburgh, PA 15213, USA. Buffingtoncw@anes.upmc.edu


Abstract

BACKGROUND AND OBJECTIVES:

Our previous studies in pigs indicate that direct connections exist between the spinal epidural space and the venous circulation. We wondered if similar connections occur in humans and have extended our investigations to human cadavers awaiting autopsy.

METHODS:

We studied 10 recently dead human bodies. We inserted 2 Tuohy needles into the epidural space of the lower thoracic spine at adjacent interspaces. We infused saline with a constant-flow pump into 1 needle and measured the resulting pressure through the other. Epidural pressure increased to a steady plateau during fluid infusion, and this value was recorded at several flow rates. The pressure decay after flow stopped was also recorded. Then we infused radiopaque contrast, removed the needles, and obtained a computed tomographic scan of the spine from the foramen magnum to the coccyx.

RESULTS:

Pressure in the epidural space increased to a plateau during saline infusion. Higher flow rates produced higher plateau pressures. Plots of plateau pressure versus infusion rate were linear in all bodies. The slope of the flow-pressure plot gave a steady-state resistance (543±638 mm Hg·s/mL). The time constant of the pressure decay curve allowed calculation of initial capacitance (0.090±0.062 mL/mm Hg). Contrast could be identified in veins around the spinal column in all bodies. Contrast was found most commonly in the deep veins of the neck (7 bodies) and in veins originating in the area of the brachial plexus (7 bodies). Contrast was found less commonly and in smaller amounts in veins draining into the azygous system (5 bodies) and the lumbar veins (5 bodies). No contrast was found in veins in the sacral area.

CONCLUSIONS:

A direct connection between the spinal epidural space and the venous circulation has been demonstrated in human cadavers. The connection is most commonly found in the cervical and upper thoracic spine.

Copyright © 2011 by American Society of Regional Anesthesia and Pain Medicine
http://www.ncbi.nlm.nih.gov/pubmed/21270727

Posted: Thu Jul 07, 2011 5:55 am
by gibbledygook
Here's evidence of problematic venous flow, this time of the venae cavae, in relation to the epidural space:

Zh Vopr Neirokhir Im N N Burdenko. 2009 Jul-Sep;(3):26-30, 32; discussion 33.

[Myelopathies in impairment of extravertebral venous blood circulation].

[Article in Russian]

Tsuladze II, Dreval' ON, Kornienko VN.


Abstract

Development of myelopathies of venous genesis is based on venous hypertension inside vertebral canal which was initially described by J. Aboulker. According to anatomical and functional features of epidural venous system, two factors contribute in development of venous congestion: decreased outflow and increased inflow. Clinical manifestation is presented by spastic movement disorders. Morphological study performed in 18 cadavers allowed to discover so called 'narrow areas' which cause impaired circulation through large feeders of caval veins, which can be discovered by selective phlebography. Main phlebographic features include stenosis, compression, atresia, thrombosis and retrograde flow towards epidural venous plexus. We examined 58 patients with spastic para- and tetraparesis of unknown nature. Phlebographic signs of venous dyscirculation were revealed in 34 cases. 28 surgical operations were performed: 24 on feeders of vena cava superior and 4 on feeders of vena cava inferior. In 18 cases we obtained satisfactory results. This investigation should be continued.


PMID: 20088446 [PubMed - indexed for MEDLINE]
http://www.ncbi.nlm.nih.gov/pubmed/20088446

Arkh Anat Gistol Embriol. 1984 Feb;86(2):43-50.

[Morphological changes in the spinal cord, its meninges and epidural structures in experimental disorders of blood flow in the venae cavae].
[Article in Russian]

Petrovskiĭ IN, Nesterov EN, Lysenko VV, Kolbasin PN.


Abstract

The experiment has been carried out on 72 dogs. The dynamics of morphofunctional changes in the spinal cord, its meninges and in the epidural structures have been investigated when the epidural veins of the spinal canal are involved into the collateral blood stream after ligation of the anterior or posterior venae cavae. During the first 24 h after disturbance of the blood stream in the venae cavae, there appears venous stasis in the vessels of the epidural structures, of the spinal cord and its meninges, in neurons and glial elements hypoxia and acidosis appear. However, in connection with reconstruction of the collateralies, compensating the disturbed blood stream, by the end of the first week the phenomena of the venous stasis disappear. As the result of further reconstruction of the collateral bed, the epidural veins of the spinal canal become the main (short) bypass. During 3-5 months after occlusion of the venae cavae not only the ventral epidural veins of the spinal canal are gradually dilating, but the veins of the roots and meninges of the spinal cord, as well. The spinal cord edema develops, its volume increases by 10-18%, neural cells undergo severe morphological changes up to their death. The phenomena of a chronic venous congestion increase in their severity during 3 years, after that compensatory and restorative changes begin prevailing.


PMID: 6712495 [PubMed - indexed for MEDLINE]
http://www.ncbi.nlm.nih.gov/pubmed/6712495

Posted: Thu Jul 07, 2011 5:57 am
by Cece
If the jugular is not a deep vein of the neck, I don't know what is.

It is very interesting that the dye was injected in the lower thoracic spine but found in the neck veins.

Posted: Thu Jul 07, 2011 7:12 am
by gibbledygook
Indeed, and from that I surmise that the neck veins drain the spine of various fluids or at least saline solution!

Posted: Thu Jul 07, 2011 8:24 am
by Cece
this fits in with some of what was presented at ISNVD on CSF fluid dynamics:
http://ccsvism.xoom.it/ISNVD/Abstract-G ... nic%20.pdf
http://ccsvism.xoom.it/ISNVD/Abstract-Beggs.pdf

Posted: Thu Jul 07, 2011 10:29 am
by gibbledygook
Ah, cool, the Beggs pdf is especially interesting. Thanks for that.

Posted: Sat Jul 09, 2011 4:59 pm
by 1eye
I was looking at fluids again. It seems Ohm got around, and his Law is the same for electricity, blood, and air. V=I*R, voltage or pressure= current or flow times resistance. A Starling Resistor is a compressible tube surrounded by a fluid which exerts an external pressure on the outside of the tube. If the outside pressure exceeds the inside, the tube collapses. If it doesn't, the outside pressure contributes to the resistance to flow inside the tube. However, the relation between the pressures, and the resulting resistance, is anything but linear, and is very complex. The model is described in this paper, but one wonders whether a better model is needed for veins and spinal fluid. Maybe a 10X scale model of a human?

In comparison, the difference between laminar and turbulent flow seems tame!

Posted: Sat Jul 09, 2011 7:46 pm
by MrSuccess
Published studies have revealed 5 -7 % of previously healthy people .....
that get hurt in motor vehicle accidents ..... soon after ....... are deemed to have MS.

The association of neck & spine trama and CCSVI ..... is telling.

No need to ligiture dogs and rats .... to see what happens when the neck is swollen from trama ........ the swelling must compress the neck veins.

It's as good a theory as any other ........... :idea:






Mr.Success

Posted: Mon Jul 11, 2011 1:02 am
by gibbledygook
FRABJOUS! I've never known what all the electricity terms like voltage or ampere meant (crap at physics but bizarrely good at chemistry!) and now I'm much closer, thank you! That paper is great for imagining the dynamics at play in and on our veins. And interesting about the accidents stuff too. I am more convinced than ever that it is flow, pressure and resistance which are of huge importance to the integrity of the cerebral vasculature and to MS, perhaps in part because I think this area has been neglected with everyone barking up the immune system tree.

At any rate I wonder why in early pregnancy I have twice experienced significant deterioration. What the hell happens to blood pressure, resistance and flow in the weeks after conception? ...I will dig around in pubmed but am doubtful I'll find anyting...perhaps it's just increased core temperature.

Posted: Mon Jul 11, 2011 1:33 am
by JohnAm
CureIous had a post about blood flow i.e. pressure, flow and resistance on this thread as well

http://www.thisisms.com/ftopict-16859.html

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Posted: Mon Jul 11, 2011 2:22 am
by civickiller
MrSuccess wrote:Published studies have revealed 5 -7 % of previously healthy people .....
that get hurt in motor vehicle accidents ..... soon after ....... are deemed to have MS.

The association of neck & spine trama and CCSVI ..... is telling.

No need to ligiture dogs and rats .... to see what happens when the neck is swollen from trama ........ the swelling must compress the neck veins.

It's as good a theory as any other ........... :idea:

Mr.Success
Upper Cervical Care!!! MS caused from neck trauma can take decades to manifest. having your atlas or C1 off can cause your spine to be misaligned which can cause compression of vein in the neck and upper chest