Saturday, 25 June 2011

CCSVI: could dehydration be a possible confounding variable?

"Way back in 1996 we wrote a letter to the Annals of Neurology highlighting the possibility of dehydration being a confounding factor when assessing MS'ers with progressive disease."

Giovannoni et al. Urinary myelin basic protein-like material as a correlate of the progression of multiple sclerosis. Ann Neurol. 1996 Jul;40(1):128-9.

"What we had found in our own studies is that the concentration of particular substance in urine correlated with disability. Why? 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 may be limited, for example during hospital visits. Why is this important for CCSVI? The venous system is a capacitance system; i.e. it stores blood. When MS'ers dehydrate themselves they will almost certainly reduce the amount of blood in the venous system, which will result in a higher chance of finding collapsed veins when doing ultrasound or doppler studies as part of a work-up for CCSVI. This may explain why it is more common in MS'ers with progressive disease; they are more likely to have bladder problems and hence more likely to dehydrate themselves."

"I wonder if the CCSVI investigators' have considered this? Do you dehydrate yourself to control your bladder?"

CoI: nil

7 comments:

  1. Very interesting Prof G.

    If you are interested why don’t you visit a centre performing CCSVI treatments and see with your own eyes. The doctor who performed my venoplasty said he would be very keen to share his experience and findings of venous insufficiency in MS patients with the neurological community.

    Regarding the ‘collapsed veins’; interestingly it does seem to be only the jugular and azygos veins that are involved. My venogram showed the shape of my jugular veins to have wide reservoir of blood in the lower third of the vein with very little downward flow beyond this, due to a considerable tight obstruction in the valve area below. My azygos on the other hand had significant narrowing in the mid part of the vein.

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  2. John, do you think it would be possible to contact the people who have had procedures for CCSVI to see how they have done? Although, not a randomised trial it may provide some useful information. What do you think?

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  3. I would be delighted to share my experiences and progress with you. I’ll drop you an email.

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  4. I think there may be some people posting on the MS Society forum who have had this procedure; also, I think there is a website dedicated to proponents of CCSVI, where you may find people willing to share their experience.

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  5. In answer to your question - yes, I am very careful not to drink too much and find myself 'caught short'. This is to do with the increased time it takes to get to the 'facilities' and the 'latch key' effect.

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  6. Canadian government to fund CCSVI treatment trials:

    http://www.msrc.co.uk/index.cfm/fuseaction/show/pageid/2479

    Splendid.

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  7. I'm always dehydrated... mouth is always dry.

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