Research: study findings do not support CCSVI hypothesis

R
Epub ahead of printRadak et al. Morphological and haemodynamic abnormalities in the jugular veins of patients with multiple sclerosis. Phlebology. 2011 Sep 8. 

Objectives: Multiple areas of narrowing and different levels of obstruction (blockage) of internal jugular and azygous veins (a condition known as chronic cerebrospinal venous insufficiency or CCSVI) recently emerged as an additional theory to the well-known autoimmune concept, explaining the aetiology of MS. The aim of this study was to evaluate the internal jugular vein (IJV) and blood flow characteristics in MS’ers and compare it with well-matched healthy individuals. 

Methods: 64 patients with clinically proven MS and 37 healthy individuals were included in this study. In all patients, internal jugular vein  anatomy and blood flow characteristics were evaluated using sonar. The patients were classified into four groups according to MS clinical form at presentation. The prevalence of abnormalities and flow problems in the internal jugular vein were assessed.

Results: The presence of narrowing, mostly defects within the veins such as valves, were observed in 28 MS’ers (43%) and in 17 controls (45.9%) (no significant difference). Significant differences were noted in relation to blood flow; 42% of MS’ers showed flow abnormalities compared to 8.1% of controls.

Conclusions: This group of MS’ers had significantly different blood flow in their internal jugular vein when compared with healthy individuals. There was no differences in relation to blockages or stenoses (medical term for narrowing of the vein). 
“It is a pity these investigators did not control for dehydration; MS’ers with bladder problems usually dehydrate themselves when visiting hospitals to reduce the chances of them needing to find a toilet urgently. Dehydration reduces central blood volume and as a result may reduce flow in the internal jugular vein.”

“Interesting that this study did not show a difference in the number of blockages or stenoses in internal jugular vein between MS’ers and controls; this would argue against the CCSVI hypothesis.”
Please see previous post in relation to dehydration: 


25 Jun 2011

We subsequently showed that the reason for this was voluntary dehydration; MS’ers with urinary symptoms often restrict their fluid intake to control troublesome urinary frequency, especially when quick access to toilet facilities 

About the author

Prof G

Professor of Neurology, Barts & The London. MS & Preventive Neurology thinker, blogger, runner, vegetable gardener, husband, father, cook and wine & food lover.

13 comments

  • "Conclusions: This group of MS'ers had significantly different blood flow in their internal jugular vein when compared with healthy individuals."

    Blimey, even when a study finds results that show abnormal blood flow from the brain in MSers you manage to give it a negative spin. Blood flow is the issue not stenosis.

  • Re ‘Blood flow is the issue not stenosis’

    Allow me to re-phrase. I would say improving the abnormal blood flow is the most important issue. Angioplasty of the stenosis does improve the blood flow in the affected veins, which also includes the azygos vein. Also for completeness, here’s the fuller wording from the ‘spin free’ zone of the MSRC.

    RESULTS:
    The presence of stenosing lesion, mostly intraluminal defects like abnormal IJV valves, were observed in 28 patients (43%) in the MS group, and in 17 patients (45.9%) in the control group (P = NS). By adding haemodynamic Doppler information in the IJV venous outflow was significantly different in 42% of MS patients showing flow abnormalities (27/64), as compared with 8.1% of the controls (3/37), P < 0.001.

    CONCLUSION:
    In our group of patients, patients suffering from MS had significantly more IJV morphological changes and haemodynamic abnormalities when compared with healthy individuals not suffering from MS. These findings can be well demonstrated by non-invasive and cost-effective Doppler ultrasound.

  • "Interesting that this study did not show a difference in the number of blockages or stenoses in internal jugular vein between MS'ers and controls; this would argue against the CCSVI hypothesis."

    How can a study that found abnormal venous outflow in 42% MS’ers, diagnosed by Doppler ultrasound, be unsupportive of the CCSVI hypothesis? The presence of stenosis is one of the five criteria for CCSVI diagnosis proposed by Zamboni. The other four criteria concern flow and reflux.

  • Re: "How can a study that found abnormal venous outflow in 42% MS’ers, diagnosed by Doppler ultrasound, be unsupportive of the CCSVI hypothesis?"

    This figure is not different from the control group. One of the Bradford-Hill criteria is specificity; i.e. it can only be found in association with the disease.

  • 'Significant differences were noted in relation to BLOOD FLOW; 42% of MS'ers showed flow abnormalities compared to 8.1% of controls.'

    42% looks different to 8.1% to me but I'm not a neurologist. Do you actually read these CCSVI article’s before drawing your conclusions. I really can’t believe you are still so astoundingly unknowledgeable on this subject on which you like to pontificate.

    I repeat their results:
    ‘Doppler information in the IJV venous outflow was significantly different in 42% of MS patients showing flow abnormalities (27/64), as compared with 8.1% of the controls (3/37), P < 0.001.’

    The presence of STENOSIS is just one of the five criteria for CCSVI diagnosis proposed by Zamboni. The other four criteria concern FLOW and REFLUX. This study found ‘patients suffering from MS had significantly more IJV morphological changes and haemodynamic abnormalities when compared with healthy individuals not suffering from MS.’

  • Re: 'Significant differences were noted in relation to BLOOD FLOW; 42% of MS'ers showed flow abnormalities compared to 8.1% of controls.'

    Because the investigators did not control for the major confounder of dehydration you can't put any weight on the flow data. As I have stated before the venous system acts as a capacitator and reduction in blood volume will affect the flow dynamics.

    In my medical physics class I learnt that flow rate is calculated by the formulae Q = A*V, where Q is the flow rate A is the cross sectional area of the vein and v is the velocity. Dehydration reduces the calibre of veins and hence the cross sectional area of the veins, which will reduce the flow. Calculating the velocity of the venous blood flow is much more complicated and is affected by pressure, the volume of blood and the velocity up stream. All these can also be affected by dehydration.

    It has been know for decades that MS'ers with bladder symptoms control their bladder function by dehydration. Any test that requires MS'ers to travel to hospital will be affected by this phenomenon. Venous doppler is no exception and therefore this should be taken into account in interpreting any flow data.

  • Re: "Wouldn't they be made to drink a lot of water before a scan like this?"

    No, not that I am aware of. The only test that requires water is a bladder scan; the water is given to get MS'ers to pass urine.

  • Re: "Will you be sharing your hypothesis with the researchers?"

    I tried to get our data on urinary concentration (a marker of dehydration) and disability published over 10 years ago and it was rejected. This was before CCSVI was an issue. May be I should try again.

  • Go for it Prof G! This is what the CCSVI debate needs – researchers with different areas of expertise actually talking to each other.

  • Re: Re: "I was thinking of how one has to drink a lot of water before getting an abdominal ultrasound scan."

    The purpose of drinking water of an abdominal ultrasound is to make sure the bladder is full; this helps the ultrasongrapher define the abdominal anatomy. This does apply NOT to venous dopplers.

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