vagus nerve compression in CCSVI in MS

[drsclafani]

Vasovagal therapy is like supercharged CCSVI treatment. It is extreme pressure ballooning combined with external compression. The goal is delivery of maximal mechanical energy to the autonomic nerve fibers running along the vein.

This is how Dr. Arata explained this. High pressure balloons combined with external compression?

cece
i have not heard that a nerve can be "somethinged" by balloon angioplasty. my hand cannot generate the pressures that the balloon provides. I cannot understand this reasoning.

Has this technique ever been written about? is there any evidence for this "vasovaagal therapy"?

if anyone has found something during a search, it would be you

S

[Cece]

No, I found nothing to support it. Yes, I was complimented enough to spend more time than I should have looking.



Looking at the placement of the vagus nerve in this Grays image, it is difficult to understand how external compression could reach the vagus nerve. It is deep within the neck.

If the vagus nerve was stimulated, should we expect vasovagal syncope (fainting, drop in blood pressure)?

Here is a mention in wikipedia of how to bring on vasovagal syncope:

Pressing upon certain places on the throat, sinuses, and eyes (also known as vagal reflex stimulation when performed clinically)

Vagal reflex stimulation might be what Dr. Arata is performing concomitantly with ballooning.

Barely relevant 1932 research showing that the vagus nerve responds to mechanical stimulation: http://ep.physoc.org/content/22/1/79.full.pdf
Vagal inhibition can be a cause of instantaneous death, indicating there may be risks to this technique: http://healthdrip.com/vagal-inhibition/

[cheerleader]

Thanks for the pic, Cece. Dr. Sclafani's right...if there was any scientific evidence regarding this treatment, you would have found it!

I met a woman at the AAN Brain Fair who has an implant in her neck to stimulate her vagus nerve....this helps her with epileptic seizures. This device is sometimes called a "pacemaker for the brain." She showed me the scar on her neck, and explained how the device delivers continual electrical charges via the vagus nerve.
http://www.epilepsy.com/epilepsy/vns

THIS IS NOT A ONE TIME THING. It's not an accidental one time only nudging of a nerve via a catheter ballooning procedure. It's an ongoing ELECTRICAL stimuli, which helps her brain. And it is FDA approved and proven to work. The woman I met said it has been a lifesaver.

I am still incredibly uncomfortable with this whole autonomic dysfunction/ballooning of jugulars once and you're better stuff. There's nothing real about it, no scientific verification, and it's being marketed as a treatment option. The REAL treatment for vagus nerve issues is VNS.
cheer

[PointsNorth]

Hi Cheer,

Did she mention the External Stimulator that hangs around the ear I featured in an earlier post on this thread? It can be used to see if the device proves beneficial before implantation. I think we should acquire one and try it out!?

Best, PN

[Cece]

http://www.cathlabdigest.com/images/fa.pdf

Potential complications whilst [femoral artery] sheath insitu and following removal include:
6.1 Vasovagal
Pressure on a large artery and pain can stimulate the vagus nerve, causing slowing of the
heart rate a drop in blood pressure.
Anxiety pain and discomfort at the puncture site may also result in a vasovagal reaction.
Early signs include pallor, nausea and/or yawning, which often present with a slowing of the
heart rate before a drop in blood pressure.
Vasovagal reactions may lead to irreversible shock if untreated.
IV atropine and IV fluids should be administered as ordered.
Oxygen should be administered via a mask @ 6l/min and the bed tilted to head low position.
Vasovagal reactions may occur whilst applying pressure to the groin therefore another
person should be present to administer treatment while pressure on the site is maintained.

This is what a one-time stimulus to the vagus nerve might look like.

A reason to stimulate only the left vagus nerve and not the right:

The left vagus nerve is stimulated rather than the right because the right plays a role in cardiac function such that stimulating it could have negative cardiac effects. [3]

http://www.caam.rice.edu/~cox/wrap/vns.pdf
(Again this is a device that stimulates the nerve multiple times a day. Very different than what effect if any might occur during a one-time procedure.)

[Cece]

http://www.karger.com/Article/FullText/85822

Neu P. · Heuser I. · Bajbouj M.
Cerebral Blood Flow during Vagus Nerve Stimulation – a Transcranial Doppler Study
Neuropsychobiology 2005;51:265–268 (DOI: 10.1159/000085822)
Abstract
Background and Objectives: Vagus nerve stimulation (VNS) is an approved treatment of partial onset seizures and has recently shown antidepressant effects in patients with treatment-resistant depression. This study was conducted to investigate whether acute VNS has an influence on cerebral blood flow (CBF) in humans. Methods: This investigation was designed as an add-on study. In 10 patients with an implanted stimulator who participated in a multicenter clinical trial to evaluate the efficacy of VNS in depression, CBF was investigated by functional transcranial Doppler at baseline (before the stimulator was turned on for the first time) and during stimulation with three different stimulation intensities in a randomized order. Results: Immediately after every increase of the current, CBF velocity showed a nonsignificant increase. Otherwise, no change of CBF above standard deviation could be registered. Conclusion: Acute VNS does not have an influence on CBF velocity in depressive patients.

This could've been interesting! But, negative results.

This might be in response to the discussion here? It adds to the discussion, certainly. From Dr. Arata over on Facebook:

Vasovagal Therapy- delivery of physical energy to periadventitial autonomic fibers. Not vagal compression.

[drsclafani]

[quote="cece"

This might be in response to the discussion here? It adds to the discussion, certainly. From Dr. Arata over on Facebook:

Vasovagal Therapy- delivery of physical energy to periadventitial autonomic fibers. Not vagal compression.

[/quote]

???????????????????????????

[Cece]

well, it gives me new words to google.

the only thing that comes up when "periadventitial autonomic fibers" is googled is a dutch MS forum discussing Dr. Arata's ideas
http://www.msweb.nl/forum/showthread.php?p=902346

The word fibers is used in relation to the vagus nerve here: http://www.bartleby.com/107/205.html

Transduction is the process of converting physical energy into neural impulses. Is that what is meant?

[Cece]

http://discovery.ucl.ac.uk/186337/

Neurocompensatory responses to balloon-catheter-induced injury of the rat carotid artery

Milner, P and Crowe, R and Loesch, A and Anglin, S and Burnstock, G and McEwan, JR (1997) Neurocompensatory responses to balloon-catheter-induced injury of the rat carotid artery. J VASC RES , 34 (1) 31 - 40.

Abstract

Percutaneous transluminal angioplasty relieves discrete arterial stenosis but causes extensive vascular injury. There is denudation of the endothelium and variable medial disruption, but the effect on adventitial structures has not been studied in detail. We have investigated the innervation of the left and right carotid arteries after unilateral balloon-catheter-induced injury. Immunohistochemical examination of the arteries 1 day after Fogarty-catheter-induced injury of the left common carotid artery revealed a reduction in the density of protein gene product 9.5 (PGP)-, substance P (SP)- and calcitonin-gene-related peptide (CGRP)-containing nerves close to the medial smooth muscle of the injured vessel. At the same time, on the side contralateral to the injury, there was a substantial increase in the density of PGP-, SP- and CGRP-containing nerves innervating the carotid artery and vasa vasorum compared to controls. Immunoassay data from these vessels showed a selective increase in SP and CGRP contents of the contralateral carotid artery (SP, controls 0.02 +/- 0.01, operated 0.59 +/- 0.32 pmol/cm; CGRP, controls 0.03 +/- 0.01, operated 0.14 +/- 0.03 pmol/cm, n = 6, p < 0.05). Neuropeptide Y levels were unchanged. Twenty-eight days after surgery, at which time a neointima was present, peptide levels were no different from controls, and the innervation of both the left and right carotid arteries and vasa vasorum was indistinguishable from the controls.

In conclusion, balloon-catheter-induced injury includes damage to the perivascular nerves and induces a transient increase in the density of sensory neuropeptide-containing nerves innervating the contralateral, uninjured side. This novel observation may reflect neurocompensatory responses to vascular injury.

Damage to the nerves during balloon angioplasty (of the carotid artery in rats) can cause a neurocompensatory response. Unfortunately it is only temporary.

[Cece]

http://ajpheart.physiology.org/content/ ... nsion.html

And a new image based on the new explanation:

it's a cross section of the vein, with the nerve fibres in the outermost layer

[Squeakycat]

[cen][/cen]

Not to support what seems like a dubious assertion that CCSVI treatment works by stimulating the vagus nerve, but, as shown here, the vagus nerve, common carotid and internal jugular are all contained within the carotid sheath Carotid Sheath.

The four major structures contained in the carotid sheath are:

• ** The common carotid artery as well as the internal carotid artery

• ** Internal jugular vein

• ** The vagus nerve(CN X)

• ** The deep cervical lymph nodes.

This suggests that the nerve would be compressed during venoplasty, but says nothing about what effect that might have.

[Anonymoose]

Personally, I think nudging the vagus or any nerve with a balloon would be much like hitting your "funny bone," a nerve. You experience instant sensation that dies away within a few moments. It just can't be the cause of PTA improvements.

The explanation that makes more sense, especially since improvements are often related to other cranial nerves, is that PTA reduces csf pressure at the nerve roots where csf drains into the veins. There also may be improved hormonal autonomic function as a result of improved perfusion (noted elsewhere re:hypoxia and loss of ca1 pyramidal hippocampus neurons). This would be a more slowly developed improvement though.

[drsclafani]

http://discovery.ucl.ac.uk/186337/

Neurocompensatory responses to balloon-catheter-induced injury of the rat carotid artery

Milner, P and Crowe, R and Loesch, A and Anglin, S and Burnstock, G and McEwan, JR (1997) Neurocompensatory responses to balloon-catheter-induced injury of the rat carotid artery. J VASC RES , 34 (1) 31 - 40.

Abstract

Percutaneous transluminal angioplasty relieves discrete arterial stenosis but causes extensive vascular injury. There is denudation of the endothelium and variable medial disruption, but the effect on adventitial structures has not been studied in detail. We have investigated the innervation of the left and right carotid arteries after unilateral balloon-catheter-induced injury. Immunohistochemical examination of the arteries 1 day after Fogarty-catheter-induced injury of the left common carotid artery revealed a reduction in the density of protein gene product 9.5 (PGP)-, substance P (SP)- and calcitonin-gene-related peptide (CGRP)-containing nerves close to the medial smooth muscle of the injured vessel. At the same time, on the side contralateral to the injury, there was a substantial increase in the density of PGP-, SP- and CGRP-containing nerves innervating the carotid artery and vasa vasorum compared to controls. Immunoassay data from these vessels showed a selective increase in SP and CGRP contents of the contralateral carotid artery (SP, controls 0.02 +/- 0.01, operated 0.59 +/- 0.32 pmol/cm; CGRP, controls 0.03 +/- 0.01, operated 0.14 +/- 0.03 pmol/cm, n = 6, p < 0.05). Neuropeptide Y levels were unchanged. Twenty-eight days after surgery, at which time a neointima was present, peptide levels were no different from controls, and the innervation of both the left and right carotid arteries and vasa vasorum was indistinguishable from the controls.

In conclusion, balloon-catheter-induced injury includes damage to the perivascular nerves and induces a transient increase in the density of sensory neuropeptide-containing nerves innervating the contralateral, uninjured side. This novel observation may reflect neurocompensatory responses to vascular injury.

Damage to the nerves during balloon angioplasty (of the carotid artery in rats) can cause a neurocompensatory response. Unfortunately it is only temporary.

Cece, they are talking about the nerves IN the wall of the artery, not on the vagus nerve. They did not look at the vagus itself.

[drsclafani]

Personally, I think nudging the vagus or any nerve with a balloon would be much like hitting your "funny bone," a nerve. You experience instant sensation that dies away within a few moments. It just can't be the cause of PTA improvements.

The explanation that makes more sense, especially since improvements are often related to other cranial nerves, is that PTA reduces csf pressure at the nerve roots where csf drains into the veins. There also may be improved hormonal autonomic function as a result of improved perfusion (noted elsewhere re:hypoxia and loss of ca1 pyramidal hippocampus neurons). This would be a more slowly developed improvement though.

i suspect that this is more likely too

[Cece]

Cece, they are talking about the nerves IN the wall of the artery, not on the vagus nerve. They did not look at the vagus itself.

I was trying to decode this: "Vasovagal Therapy- delivery of physical energy to periadventitial autonomic fibers. Not vagal compression"

I thought periadventitial autonomic fibers might mean the nerves within the outer layer of the blood vessel. These nerves within the blood vessel can be damaged by balloon angioplasty. The image above has them labelled as parasympathetic and sympathetic nerves, contained within the tunica adventitia. If they were damaged however it would be very localized. It's possible that I am trying to make sense of something that is nonsensical. I am very uncomfortable with the ballooning of nonobstructed jugulars.