Reversible cerebral vasoconstriction syndrome without typical thunderclap headache: highresolution magnetic resonance imaging features

Reversible cerebral vasoconstriction syndrome (RCVS) is characterized by sudden onset severe headache with or without focal neurologic deficits and is accompanied by segmental or multifocal intracranial arterial vasospasms that resolve within 3 months. The typical RCVS has thunderclap headache but patients with RCVS without this type of headache have been reported. Herein we introduce an unusual case of RCVS without thunderclap headache, together with typical high-resolution magnetic resonance imaging (HR-MRI) features of RCVS showing the possible mechanisms of this condition. The present case suggests that HR-MRI features like dynamic negative remodeling but no enhancement may be a suspicious sign for RCVS, especially in cases with atypical presentation. HR-MRI can be helpful in direct visualization of the vasoconstriction of RCVS and differential diagnosis of other diseases, possibly even without serial examinations. Further research should be performed to test the diagnostic accuracy of HR-MRI in patients with RCVS.