There's webs, valves, and, most importantly, flow. Remember, Dr. Zamboni's words..."it's not about the architecture (stenosis), it's about the flow."
The Origin and History of CCSVI
A Basic Definition
CCSVI stands for “Chronic Cerebrospinal Venous Insufficiency,” a condition where people have obstructed blood flow in the veins that drain the central nervous system (the brain and spinal cord). Research indicates that CCSVI is significantly correlated with multiple sclerosis.1, 2,3,4
As a result of these venous abnormalities, the blood flow rate through the central nervous system back toward the heart may become slowed, and blood may reflux back toward the brain and spine.1
People with CCSVI have one or more of the following blockages of the veins that drain blood from the central nervous system:
Stenosis is an abnormal narrowing of the veins that restricts blood flow. Types of stenoses include the collapse of the vein, twisting of the vein, ring-like narrowings in the vein, and other similar obstructions
An abnormal valve, septum, flap, or membrane that blocks or inhibits blood flow through the veins
Atresia, hypoplasia, or agenesis are severe venous problems, including veins that are partially closed, underdeveloped, minimally formed, or almost entirely missing
The animation below shows how stenosis in veins draining the central nervous system can cause CCSVI. This animation was provided by Dr. Zamboni.
From the CCSVI alliance webpage (pardon my liberties taken)
Stenosis is causing reflux ... I'm pretty sure Dr. Siskin didn't go into his office workers veins to see if they had stenosis. I have reflux, you have reflux. It's what happens in the milli-seconds that the heart isn't pumping ... the blood stops when it hits a valve (think IJVs) ... and bounces back for that milli-second. It happens.
When it's constant though due to the above mentioned stenosis ... that's when it's a problem.
Please try to follow along ...