Table 3. Results of the partial least squares correlation analysis comparing the cerebrospinal fluid variables with internal jugular vein cross-sectional areas for the lower neck (C5-T1) and upper neck (C2-C4), in both the MS patients and the healthy controls (based on 100000 simulations).

Subjects	Group 1 variables	Group 2 variables	No. subjects included	Measured Inertia	Odds	Significance p value	Effect size (Cramer’s V)
Healthy subjects	NNF, NPF	C7-T1 RIJV CSA, C7-T1 LIJV CSA, C5-C6 RIJV CSA, C5-C6 LIJV CSA	71	47.65	25:1000	<0.001**^ <0.001**^^	1.072^ 0.585^^
Healthy subjects	NNF, NPF	C4 RIJV CSA, C4 LIJV CSA, C2-C3 right collateral CSA, C2-C3 RIJV-CSA, C2-C3 LIJV CSA, C2-C3 left collateral CSA	71	35.03	347:1000	0.513^ <0.001**^^	0.021^ 0.585^^
RR MS patients	NNF, NPF	C7-T1 RIJV CSA, C7-T1 LIJV CSA, C5-C6 RIJV CSA, C5-C6 LIJV CSA	63	16.21	767:1000	<0.001**^ <0.001**^^	1.072^ 0.579^^
RR MS patients	NNF, NPF	C4 RIJV CSA, C4 LIJV CSA, C2-C3 right collateral CSA, C2-C3 RIJV CSA, C2-C3 LIJV CSA, C2-C3 left collateral CSA	63	33.34	361:1000	0.513^ <0.001**^^	0.021^ 0.579^^

RR MS, relapsing-remitting multiple sclerosis, NNF, net negative flow; NPF, net positive flow; PPV, peak positive velocity; PNV, peak negative velocity; RIJV, right internal jugular vein; LIJV, left internal jugular vein; CSA, cross sectional area.

^ Comparison of the between-group odds for the healthy subjects and RR MS patients

^^ Comparison of the within-group odds for the respective healthy subject and RR MS patient groups

* p values less than 0.05 considered trends using Chi-square test

** p values less than 0.01 considered significant using Chi-square test