Effect of cerebral sinus venous thrombosis and its location on cerebral blood flow: a [15O]water PET study in acute stroke patients compared to healthy volunteers

Background Symptoms in acute cerebral sinus venous thrombosis (CSVT) are highly variable, ranging from headaches to fatal stroke, and the basis for this high inter-individual variability is poorly understood. The present study aimed to assess whether acute CSVT significantly alters regional cerebral blood flow (CBF), if findings differ from CBF patterns know from large-artery occlusion in stroke, and whether the pattern of CBF alterations depends on clot location. Therefore, we retrospectively analyzed 12 patients with acute CSVT 10.6 +/- 4.6 days after symptom onset and ten healthy volunteers who underwent [O-15]water PET (two scans each, 300 +/- 14 MBq [15O]water). Static image datasets (15-75 s after injection; normalized to cerebellum) reflecting relative CBF (rCBF) were analyzed using voxel- and region-of-interest-based analysis (AAL3-atlas). We mirrored datasets of patients with left-sided CSVT to harmonize the affected hemisphere. Results Seven and five patients showed right- and left-sided CSVT, respectively. The superior sagittal sinus (SSS) was involved in 8/12 patients. CSVT patients had extensive rCBF deficits in the voxel-based analysis with accentuation in the right (ipsilateral) frontal cortex and caudate nucleus compared to controls, which were most pronounced in cortical areas in those with involvement of the SSS (8/12), and in subcortical areas in those without involvement of the SSS (4/12; p < 0.05, false discovery rate corrected). ROI-analysis demonstrated significant frontal (p = 0.01) and caudate nucleus (p = 0.008) rCBF deficits driven by patients with and without SSS occlusion, respectively. Conclusions [O-15]water PET was able to visualize characteristic patterns of impaired rCBF, which were different from intracranial large-artery occlusion in acute ischemic stroke, and exhibited substantial rCBF alterations depending on the involvement of the SSS. Our findings provide novel insights into the effects of disturbed venous drainage on CBF in acute CSVT, which may aid in understanding the pathophysiology, and guide future therapy of acute CSVT.