RCVS is a low incidence disability with a wide variety of etiologies and a wide array of symptoms. The main symptoms involve thunderclap headache, accompanied sometimes with various neurological deficits such as often complicated by ischemic or hemorrhagic strokes. Although RCVS may be spontaneous, it is often provoked by postpartum state or exposure to provocative drugs . However, the clinical outcome may be severe when complicated with stroke, which may lead to death. RCVS has been reported to be the commonest cause of isolated cSAH in patients less than 60 years old , and more than 30% of patients with RCVS suffer from cSAH . RCVS could perform haemorrhagic and ischaemic complications and sometimes occurs in concert with PRES. As for PRES, it is characterized by the acute onset of neurologic symptoms including headache, altered mental status, visual changes and seizures, with accompanying vasogenic edema.
PRES and RCVS are rare neurological disorders with complex physiopathology which has been not yet fully understood. To the best of our knowledge, the co-occurrences of RCVS and PRES have been reported in the following conditions, such as postpartum, post-transfusion, intracranial hypotension, licorice and hemolytic uremic syndrome. The co-occurrences have also found after bilateral carotid paraganglioma resection, oral contraceptive pills，intravenous immune globulin therapy in Guillain-Barre syndrome and heart transplantation [7, 12-21]. The pathogenesis of RCVS or PRES has been poorly understood, however, autonomic dysregulation, oxidative stress, and genetic predisposition are postulated .
To data, there were only two cases reported about RCVS presenting as the coexistence of cSAH and PRES. The first case was a 53-year-old woman with RCVS, suffering from an unruptured cerebral aneurysm and presenting as cSAH, PRES and cerebral infarction . Another one was a rare case of a 15-year-old girl suffered from RCVS induced by tacrolimus . As for the pathophysiology of RCVS, angiogram analysis showed more severe vasoconstriction in distal versus proximal segments in all lesion types . Early distal vasoconstriction was associated with lobar ICH and cSAH, and delayed proximal vasoconstriction with infarction . Also it was reported that early vasogenic cerebral edema was due to small vessels dysfunction with acute disruption of the blood-brain barrier . However, the pathophysiology of hemorrhagic complications underlying in RCVS or PRES remains uncertain.
The strengths of our study were listed as follows. Firstly, our case revealed a bilateral cSAH and high-intensity lesions in the bilateral parieto-occipital lobes. Our case also indicated a complete resolution after 3 months. To the best of our knowledge, only two cases have been previously described of RCVS presented as cSAH and PRES. Secondly, to date, RCVS is typically encountered during one to three weeks after delivery. However, it can also occur 6 weeks later after delivery . Our case performed with RCVS 50 days after delivery, which raised the importance of the early recognition of this syndrome until 50 days after delivery.
In conclusion, cSAH and PRES are common complications of RCVS. RCVS is considered a rare syndrome with complex physiopathology [27-28]. Our case also raises awareness of the diagnosis of RCVS when initial brain and vascular imaging are normal. Early diagnosis and treatment are of great importance for a better prognosis.