Headache in cerebral venous sinus thrombosis revisited: Exploring the role of vascular congestion and cortical vein thrombosis

Background and purpose Headache constitutes the most common symptom of cerebral venous sinus thrombosis (CVST), but its pathophysiology is unclear. We sought to investigate the potential mechanism for headache genesis in patients with CVST based on its imaging correlates. Methods A subgroup of CVST patients having headache as the predominant symptom without significant parenchymal lesion were retrospectively analysed for imaging features of vascular congestion (VC), in addition to cortical venous (CVT) and dural sinus thrombosis (DST) on magnetic resonance imaging. Headache and imaging patterns were classified into lateralized and nonlateralized phenotypes and their correlation was sought. Results Among 41 patients included, 28 had lateralized headache (LH group; 15 males; mean age 32.25 ± 9.19 years) while 13 had nonlateralized headache (non-LH group; six males; mean age 27.15 ± 8.65 years). Headache characteristics in both the groups were quite similar. Imaging showed VC in 39 of 41 and CVT among 35 of 41 patients, which were lateralized in 23 of 39 and 18 of 35 patients, respectively. Nearly all lateralized imaging patterns (21 of 23 for VC and 17 of 18 for CVT) occurred in the LH group and ipsilateral to (concordant) headache, while the non-LH group showed lateralized VC and CVT in only two and one patient respectively. Sinus thrombosis was lateralized in both groups irrespective of headache laterality. Whole cohort headache-imaging laterality (including patients with nonlateralized headache and nonlateralized imaging) concordance was 31 of 39, 24 of 35 and 18 of 41 for vascular congestion, cortical vein thrombosis and dural sinus thrombosis respectively. Conclusion Co-localization of VC and CVT with overlying headache might provide a possible explanation of headache and its laterality in patients with CVST.