Hyperintense vessels on flair imaging in reversible cerebral vasoconstriction syndrome

Objectives: To study the frequency and significance of distal hyperintense vessels (HVs) on fluid-attenuated inversion recovery (FLAIR) imaging in patients with reversible cerebral vasoconstriction syndrome (RCVS). Methods: Patients with RCVS were recruited during 2002 through 2009. Prominence and location of HVs on FLAIR images during the acute and recovery stages were documented. Clinical profiles, vasoconstriction scores, mean flow velocities of the middle cerebral artery (V _MCA) and posterior cerebral artery (V _PCA), and the Lindegaard index (LI) were collected for analysis. Results: Ninety-five patients with RCVS (11M/84F, mean age 47.8 ± 10.9 years) were recruited. Twenty-one (22.1%) had FLAIR HVs, which were noted at a mean of 14.3 ± 12.7 days and resolved by 44.9 ± 18.8 days. Compared with patients without HVs, patients with this finding had higher vasoconstriction scores for all arterial segments; higher V _MCA (121.0 ± 39.5 cm/s vs. 93.3 ± 27.8, p = 0.002), V _PCA (73.3 ± 35.0 vs. 50.5 ± 17.8 cm/s, p = 0.010), and LI (2.8 ± 1.2 vs. 1.9 ± 0.5, p = 0.018), and complications such as posterior reversible encephalopathy syndrome (PRES) [8/21 (38%) vs. 0/74 (0%), p < 0.001] or ischemic stroke [5/21 (24%) vs. 1/74 (1%), p = 0.002]. Conclusions: HVs in patients with RCVS might be attributed to the failure of cerebrospinal fluid (CSF) signal nulling on FLAIR imaging due to severe cerebral hemodynamic derangements and were associated with more frequent ischemic complications.