What are the implications of this? If we've had our jugulars ballooned, should we be avoiding coughing and 'acute increases in intrathoracic pressure' (whatever that means)?
Jugular ballooning where valves are functioning normally should be fine. I asked Dr. Dake about this, since Jeff is a trumpeter...he's still playing, no problem.
If you start from the beginning of this thread, I mention Dr. Schelling and his concern. He has always believed that it is intrathoracic reversal of flow and pressure which causes Dawson's Fingers type lesions. For a review of Dr. Schelling's work on MS lesions, please see his book:
This is just a theory, and has not been clarified at this point. But the valves DO prevent throacic pressure from sending venous reflux up into the brain.
For an explanation of thoracic pressure changes and venous return:
http://www.cvphysiology.com/Cardiac%20F ... cic%20pump
I also mention Dr. Chung's work on internal jugular vein valve insufficiency (IJVVI) and transient global amnesia and LA in the aging. (His papers are on pub med) Other researchers are finding the connection of valve insufficiency.
My point is that we simply do not know enough about jugular vein valves at this point to say they are inconsequential or unnecessary. There is a reason why 97% of us have them. Certainly, those who do not have valves should try to avoid head down positional changes such as inversion poses in yoga, or upside down roller coaster rides....but no one can avoid valsalva manuevers forever...you're going to cough, or strain, or have sex. And thoracic pressure changes are autonomic.
I feel very responsible for making sure no one is harmed...it was terrible seeing the adverse outcomes at Stanford, and made me much more wary. I feel it is important to discuss what we do not know about CCSVI treatment going forward-