Background: Studies have previously shown greater arterial and venous extracranial
vascular changes in persons with multiple sclerosis (PwMS) when compared to healthy controls
Objectives: To determine the change in the number and size of secondary neck vessels in PwMS
and HCs over a 5-year follow-up period.
Methods: Both at baseline and follow-up, 83 PwMS and 25 HCs underwent magnetic resonance
angiography (MRA) imaging and analysis. The number and cross-sectional area (CSA) of all secondary
neck vessels (excluding the common/internal carotid, vertebral artery, and internal jugular
vein) measured at levels from C2-T1 were determined by semi-automated edge detection/
contouring software. The longitudinal change in the number and CSA of the secondary neck
vessels from the PwMS and HCs were analyzed by non-parametric Wilcoxon repeated measure.
Benjamini-Hochberg procedure adjusted for false discovery rate (FDR).
Results: For over 5 years, PwMS demonstrated a consistent longitudinal decrease in both the
number of secondary neck vessels (Z-change between -3.3 and -5.4, q=0.001) and their CSA (Zchange
between -2.9 and -5.2, q=0.004). On the contrary, the HCs did not demonstrate a significant
longitudinal change in secondary neck vessels over the follow-up period. Due to the longitudinal
decrease, the PwMS showed a lower number of secondary neck vessels when compared to
HCs measured at follow-up (p<0.029, except for C4 with trending p=0.071). The PwMS changes
were also corroborated within each MS phenotype.
Conclusion: PwMS demonstrate a significant mid-term decrease in the number and the size of the
secondary neck vessels. The clinical relevance of these findings and the effect on intracranial
blood flow are currently unknown.