PUBLISHED CRITERIA	2011 CRITERIA
1. Reflux present in an outflow pathway (IJV and/or VV) with the head at 0° and 90°	1a. Bidirectional flow in one or both of the IJVs in both positions or bidirectional flow in one position with absence of flow in the other position and/or
	b. Reversal of flow or bidirectional flow in one or both VVs in both positions.
2. Reflux in the intracranial veins/deep cerebral veins	The Committee recommends that this criterion be used as an additional criterion (see Appendix V) and defined as bidirectional flow in the intracranial veins and sinuses.
3. High resolution B-mode evidence of proximal IJV stenosis and/or other B-mode anomalies	3a. Reduction of IJV CSA in supine position to ≤0.3 cm 2 which does not increase with Valsalva maneuver (performed at the end of the examination) and/or
	b. Intraluminal defects such as flaps, septa or malformed valves combined with hemodynamic changes (block, reflux, increased blood flow velocity). Valve leaflet/s immobility confirmed by M-mode.
4. Flow not Doppler detectable in the IJVs and/or VVs despite numerous deep inspirations	4a. Absence of detectable flow in the IJVs and/or VVs, despite numerous deep inspirations, in both sitting and upright positions or
	b. Absence of detectable flow in IJVs and/or VVs in one position, despite numerous deep inspirations, and bidirectional flow detected in the other position, same side.
5. Negative ΔCSA in the IJV	5a. CSA of the IJV is greater in the sitting position than in the lying position or
	b. appears almost unchanged despite change in position.