Criterion* | No. (%) of participants† | p value | OR (95% CI)‡ | |
---|---|---|---|---|
Patients n = 115 | Controls n = 60 | |||
Criterion 1: reflux (IJV, VV: right and left, upright and supine) | 0.3 | |||
None | 68 (59) | 30 (50) | ||
1 vein | 25 (22) | 22 (37) | ||
2 veins | 11 (10) | 5 (8) | ||
3 veins | 9 (8) | 3 (5) | ||
4 veins | 2 (2) | 0 (0) | ||
Criterion 3: IJV stenosis (right and left) | 0.4 | |||
Both normal | 89 (77) | 52 (87) | ||
1 abnormal | 17 (15) | 6 (10) | ||
2 abnormal | 9 (8) | 2 (3) | ||
Criterion 4: no Doppler-detectable flow (IJV, VV: right and left, upright and supine) | > 0.9 | |||
Normal | 113 (98) | 59 (98) | ||
1 vein | 2 (2) | 1 (2) | ||
Criterion 5: negative CSA in IJV (right and left) | 0.2 | |||
Change in CSA > 0 | 94 (82) | 54 (90) | ||
Change in CSA ≤ 0 | 21 (18) | 6 (10) | ||
No. of ultrasound criteria met | ||||
≥ 1 | 67 (58) | 38 (63) | 0.6 | 0.9 (0.4–1.6) |
≥ 2 | 23 (20) | 6 (10) | 0.1 | 2.2 (0.8–7.2) |
≥ 3 | 6 (5) | 1 (2) | 0.5 | 3.2 (0.3–151.8) |
≥ 4 | 0 (0) | 0 (0) | NA | NA |
0 | 48 (42) | 22 (37) | 0.6 | |
Exactly 1 | 44 (38) | 32 (53) | 0.08 | |
Exactly 2 | 17 (15) | 5 (8) | 0.3 | |
Exactly 3 | 6 (5) | 1 (2) | 0.4 | |
Exactly 4 | 0 (0) | 0 (0) | NA |
Note: CI = confidence interval, CSA = cross-sectional area, IJV = internal jugular vein, NA = not applicable, OR = odds ratio, VV = vertebral vein
↵* All criteria as presented by Zamboni and colleagues.3,4 Criterion 1 = reflux in the IJVs and/or VVs in sitting or supine position, defined as reflux > 0.88 s; criterion 3 = Doppler B-mode evidence of IJV stenosis, defined as local reduction of cross-sectional area < 50% and/or < 0.3 cm2 in supine position; criterion 4 = flow not Doppler-detectable in the IJVs and/or VVs; criterion 5, reverted postural control of the main cerebral venous outflow. For the current study, criterion 2 (transcranial Doppler assessment of internal cerebral veins) was not performed.
† Except where indicated otherwise.
↵† Fisher’s exact test for patients and controls meeting 1 or more US criteria, 2 or more US criteria, 3 or more US criteria, or 4 or more US criteria.