Internal jugular vein narrowing and body mass index in healthy individuals and multiple sclerosis patients

Internal jugular vein (IJV) narrowing has been implicated in central nervous system (CNS) disorders. Body mass index (BMI) is a cardiovascular risk factor that has been also linked to CNS diseases, however it is unknown whether a relationship exists between IJV narrowing and BMI. The objectives were to assess the relationship between IJV cross-sectional areas (CSA) and BMI in healthy individuals (HI) and multiple sclerosis (MS) patients. A total of 388 subjects (194 age- and sexmatched HI and MS patients) received magnetic resonance venography and structural brain magnetic resonance imaging at 3T. Region of interest analysis was performed using a semiautomated contouring-thresholding technique to determine the minimum CSA of the IJVs at C2/C3, C5/C6, and C7/T1 cervical levels. Partial correlation analyses were used to determine the associations. Increased BMI was related to increased IJV CSA at lower cervical levels (r=0.240, P<0.0001 at C5/C6 and r=0.293, P<0.0001 at C7/T1) in both MS patients and HI. Both MS and HI, showed associations between increased BMI and IJV CSA measures, particularly at lower cervical locations, in individual group analyses. No differences in association between BMI and IJV CSA were observed between HI and MS patients. Relationship between IJV CSA and BMI were not significant at upper cervical locations in the studied groups. Increased BMI is associated with IJV CSA widening, rather than narrowing, at lower cervical levels in both MS patients and HI. This finding warrants further investigation, but indicates that BMI can obscure interpretation of IJV CSA narrowing.