Distribution of jugular vein valve incompetence (IJVVI) in 20 patients in relation to straight sinus (SS) drainage side (group A–C) and preceding Valsalva manoeuvre (VM)
| Group A | Group B | Group C | ||||
|---|---|---|---|---|---|---|
| All | With VM | All | With VM | All | With VM | |
| Group A: right sided SS drainage; group B: left sided SS drainage; group C: bilateral SS drainage. Bold numbers indicate plausible constellations according to the hypothesis (left: matching SS drainage and IJVVI; right: matching SS drainage and IJVVI, including a reported VM). | ||||||
| Right sided IJVVI | 3 | 1 | 1 | 1 | 5 | 3 |
| Left sided IJVVI | 3 | – | 1 | 1 | – | – |
| Competent valves | 2 | – | 3 | 1 | 2 | 1 |