Among patients with reversible cerebral vasoconstriction syndrome (RCVS), white matter hyperintensities (WMHs) evolve with the severity of the syndrome and appear to be partially caused by regional hypoperfusion, according to a study in JAMA Neurology. Additionally, this study demonstrated that WMHs in RCVS may also be attributed to the transmission of high pulsatile flow to the microcirculation.
Researchers from Taiwan prospectively enrolled 65 patients with RCVS receiving care at the headache center or emergency department of Taipei Veterans General Hospital during a 3-year period. Following diagnosis of RCVS, patients received oral nimodipine 30 mg to 60 mg every 4 hours or intravenous nimodipine 0.5 to 2.0 mg/h with concomitant blood pressure monitoring.
In order to evaluate the pathogenesis and spatiotemporal distribution and evolution of WMHs in these patients, the investigators obtained serial isotropic 3-dimension fluid-attenuated inversion recovery sequences using 3-T magnetic resonance imaging (MRI). Additionally, the researchers used transcranial and extracranial color-coded sonography upon enrollment and during the 1- and 2-month follow-up periods.
A total of 162 MRI evaluations were performed during the study period. At week 3 following the onset of RCVS, the investigators observed a total mean (SD) WMH peak of 3.2 (4.4) cm3. This volume decreased to 0.8 (0.6) cm3 by week 4. In all patients, WMHs were most often distributed in the frontal and periventricular regions.
Additionally, the WMH load was significantly associated with the Lindegaard index, which denoted vasoconstriction severity, in the second week following disease onset (r = 0.908; P <.001). The findings also demonstrated associations between WMH load and the resistance and pulsatility indexes of the internal carotid artery.
The use of nimodipine therapy in all enrolled patients may have limited the findings by potentially altering the participants’ clinical course.
The researchers add that WMHs “in patients with RCVS are partially reversible, which should be known by both clinicians and patients.”
Chen S-P, Chou K-H, Fuh J-L, et al. Dynamic changes in white matter hyperintensities in reversible cerebral vasoconstriction syndrome [published online June 4, 2018]. JAMA Neurol. doi: 10.1001/jamaneurol.2018.1321