[Reversible cerebral vasoconstriction syndrome with cortical subarachnoid hemorrhage presenting as thunderclap headache-a long followed up case].

A 59-year-old woman presented with thunderclap headache. Cranial CT showed cortical subarachnoid hemorrhage (cSAH) at the right parietal lobe and cerebral angiography on day 5 revealed multiple cerebral arterial constriction, diagnosed as reversible cerebral vasoconstriction syndrome (RCVS). We could not detect vasoconstriction in MRA at the first examination on day 4, and vasoconstrictive finding appeared around Willis circle 8 days later. There was a temporal difference in a cephalalgic symptom and vasoconstrictive appearance. Clinical symptoms completely recovered and head CT, MRI/MRA findings were reversible after two months, reflecting a rather good RCVS outcome. However, we also followed up this case precisely using single photon emission computed tomography (SPECT) with easy Z-score imaging system (e-ZIS), and hypoperfusion at the locus of cSAH persisted for more than one year. This finding strongly suggests that tissue damage in the cSAH locus induced by RCVS may be subclinicaly irreversible, even though clinical symptoms and abnormalities in cranial MRI and MRA completely recover.SPECT may be a high sensitive technique to detect the irreversible lesion in RCVS.