Got it. The existence of reflux due to single vessle obstruction is clearly acceptedhere, altho they are not sure of the mechanism. When it is associated with CCSVI however, it somehow becomes unbelievable.
"In our opinion, some of
these cases may have been related to unilateral in
nominate vein obstruction.
Reflux into cervical veins during brain-flow imag
ing has been reported in the absence of venous ob
struction on correlative radiographic venograms (9).
The reflux was ascribed to variations of blood flow
in veins with absent or incompetent valves, accentu
ated in some instances by a Valsalva maneuver.
Other investigators (8,10), however, were unable to
induce jugular reflux with the Valsalva maneuver,
and the possible role of this mechanism in producing
jugularâ€”duralsinusesâ€”jugularreflux remains unclear."