Increased microscopic brain permeability is observed during acute stage of reversible cerebral vasoconstriction syndrome (RCVS), according to study findings published in Neurology. Furthermore, the research suggests that impaired cerebral microvascular compliance and white matter hyperintensity (WMH) formation could be related to dynamic changes in blood-brain barrier (BBB) permeability.
RCVS is a complex neurovascular disorder with an unclear pathogenesis. It’s characterized by recurrent thunderclap headaches and cerebral vasoconstrictions and associated with complications such as cerebral infarction convexity subarachnoid hemorrhage, and intracerebral hemorrhage, according to the researchers. Using contrast-enhanced T2–fluid-attenuated inversion recovery (CE-T2-FLAIR) imaging, previous research has detected BBB disruption in some patients with RCVS, suggesting the importance of BBB in this disorder’s pathogenesis.
The objective of the current study was to investigate whether patients with RCVS had altered BBB permeability and whether there’s a dynamic change.
In the prospective cohort study, researchers used 3T dynamic contrast-enhanced magnetic resonance imaging (MRI) to measure microscopic BBB permeability, which was assessed by determining the whole-brain and white matter hyperintensity (WMH) Ktrans values. Researchers assessed the correlation of whole-brain Ktrans permeability with vascular and clinical measures in transcranial color-coded sonography. The study included a total of 176 and 363 scans, which were separated into an acute group (≤30 days; n=76) and remission group (≥90 days; n=51) based on onset-to-examination time.
Values for whole-brain Ktrans were similar between patients with vs without macroscopic BBB disruption in acute or remission stage. There was a significant decrease in whole-brain Ktrans from acute to remission stages (P <.001). In contrast, the researchers reported that WMH Ktrans values were significantly increased compared with mirror references and significantly reduced from acute to remission stages (P <.001). Significant correlations were found between whole-brain Ktrans and mean pulsatility index (P =.029), mean resistance index (P =.002), and distal-to-proximal ratio of resistance index (P <.001) of M1 segment of middle cerebral arteries at 10 to 15 days following onset.
Additionally, they reported that the time-trend curve of whole-brain Ktrans showed dynamic changes during course of the disease, which was considered “similar to temporal trends of vasoconstrictions and WMH.”
According to the researchers, study limitations included the limited scan ranges of the dynamic control enhanced-MRI.
Based on the findings, they concluded that a microscopic BBB “disruption exists in acute-stage cases of RCVS, even without visible macroscopic” BBB leakage.
Wu CH, Lirng JF, Wu HM, et al. Blood-brain barrier permeability in patients with reversible cerebral vasoconstriction syndrome assessed with dynamic contrast-enhanced MRI. Neurology. Published online September 9, 2021. doi:10.1212/WNL.0000000000012776