Table 2

 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 AGroup BGroup C
AllWith VMAllWith VMAllWith 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 11 5 3
Left sided IJVVI3 1 1
Competent valves23121