Introduction: Posterior reversible encephalopathy syndrome (PRES) and reversible cerebral vasoconstriction syndrome (RCVS) are diagnoses that have a clinical and radiographic overlap. One particular overlap includes the presence of hemorrhage, which we studied in each population to determine its effect on outcomes. Objective: To compare characteristics and outcomes of hemorrhagic PRES and hemorrhagic RCVS populations. Methods: We conducted a review of the electronic health record at a single tertiary center from January 2008 to December 2018. Inclusion criteria were 18 years or older with clinical and radiographic evidence of PRES or RCVS. Patient demographics, presenting symptoms, imaging findings, and outcomes were compared between PRES and RCVS groups. Poor outcome was defined as discharge to skilled nursing facility or death. Analysis was performed using Pearson’s Chi-Square test. Results: Among 281 PRES and 98 RCVS cases, intracranial hemorrhage was seen on imaging in 51 PRES cases (18%) and 34 RCVS cases (35%). Headache was present in all patients with hemorrhagic RCVS but only seen in 40% of hemorrhagic PRES. Use of antidepressants or drugs of abuse was more frequent with hemorrhagic RCVS (53%) as compared to hemorrhagic PRES (7%, p <0.05). Among hemorrhagic PRES, presence of intraparenchymal hemorrhage but not subarachnoid hemorrhage was associated with vasoconstriction on arterial imaging (p<0.05). Length of stay was longer for both hemorrhagic PRES and hemorrhagic RCVS (p<0.001) compared those without hemorrhage. Presence of focal neurological deficits, motor and sensory, was associated with poor outcomes in hemorrhagic RCVS patients (p<0.05). Discharge to a rehabilitation facility was associated with hemorrhagic PRES (p<0.05), no association in those without hemorrhage. There is no evidence that discharge location is significantly different between RCVS hemorrhage and non-hemorrhage groups. Conclusion: Hemorrhage in PRES and RCVS is associated with more clinical deficits at presentation and longer hospital stays. Underlying vasoconstriction is frequent and associated with hemorrhagic PRES.

Objectives: Posterior Reversible Encephalopathy Syndrome (PRES) is characterized as reversible vasogenic cerebral edema in a posterior-dominant distribution. Some patients with PRES have diffusion-weighted imaging (DWI) changes on MRI, as well as transient arterial stenosis. We examined the association between arterial stenosis and presence of hemorrhage and MRI-DWI changes in PRES. Methods: We retrospectively identified patients with PRES in electronic health records at a single health system from January 2008 to December 2018. We included patients age 18 years or older with clinical and radiographic evidence of PRES and arterial imaging (CT or MR angiography or digital subtraction angiogram). Any arterial stenosis was noted, with reversibility determined by repeat imaging. Patient characteristics, disease presentation, hospital lengths of stay and discharge dispositions, as well as imaging findings were collected and statistical analysis was used. Results: Of 281 patients with PRES, 169 had arterial imaging. Thirty-two (18.9%) had arterial stenosis and 60% had resolved arterial stenosis on follow-up imaging. Patients with arterial stenosis were younger compared to those without (47 v 55 years, p =0.03), however they did not differ in symptoms of presentation or comorbid conditions. Of note, arterial stenosis was associated with intracerebral hemorrhage[34% with stenosis and 18% without stenosis, p=0.05). However, the presence of MRI DWI lesions did not correlate with arterial stenosis [14/32 (44%) with stenosis, 49/137 (36%) without stenosis, p=0.42]. Among 97 patients with follow-up MRI, the presence of arterial stenosis was not associated with greater FLAIR reversibility. Furthermore, hospital length of stay or discharge disposition was not associated with arterial stenosis in PRES. Conclusions: Arterial stenoses are found in 19% of PRES patients, and most are reversed on follow-up imaging. They are also associated with hemorrhagic PRES, but not with MRI-DWI lesions or degree of FLAIR reversibility.

Introduction: Posterior reversible encephalopathy syndrome (PRES) and reversible cerebral vasoconstriction syndrome (RCVS) might represent a pathophysiological spectrum. They are commonly diagnosed separately, based on prominent clinical features. We aimed to compare clinical and radiographic findings of PRES and RCVS. Methods: We performed a retrospective study of adult patients admitted to a tertiary medical center from February 2008 until February 2018 and were diagnosed with PRES or RCVS. Patient demographics, risk factors, clinical features, imaging, and outcomes were compared. Appropriate statistical tests were used to compare the variables and significant findings are reported. Results: There were 281 PRES and 98 RCVS cases meeting diagnostic criteria. Seizures, encephalopathy, and hypertension were more common with PRES, whereas headache was more common with RCVS (p <0.001). Hypertension and transplant recipient or immunocompromised status were associated with PRES (p <0.001), as did diabetes mellitus (p <0.05). Marijuana use, smoking, and obesity were associated with RCVS (p <0.05). ). Intraparenchymal or subarachnoid hemorrhage was found in 51 PRES cases and 34 RCVS cases. Arterial stenosis was present in 19 % of PRES cases. Brain FLAIR MRI hyperintensity that was reversible on follow-up was present in 26% of RCVS cases. Conclusion: PRES and RCVS share common clinical characteristics and might represent a pathophysiological spectrum, though distinct clinical features were noted in our retrospective analysis.

Introduction: Reversible cerebral vasoconstriction syndrome (RCVS) may co-occur with brain MRI T2/FLAIR sequence changes, and posterior reversible encephalopathy syndrome (PRES) may be associated with cerebral vasoconstriction. Both entities with overlapping features may be considered as a single group. We compared the isolated RCVS group to the overlapping group to investigate clinical and radiological features, with a focus on vessel involvement. Methods: We performed a retrospective study of adult patients admitted to a tertiary medical center from February 2008 until February 2018 and who were diagnosed with PRES or RCVS. Overlap cases consisting of PRES with vasoconstriction and RCVS with reversible MRI T2/FLAIR changes were compared to isolated RCVS cases. Clinical and radiological features of both groups were compared with each other. Involved vessel segments were classified as internal carotid artery, M1 and M2 middle cerebral artery, A1 and A2 anterior cerebral artery, P1 and P2 posterior cerebral artery, vertebral artery, and basilar artery. Severity was also graded (1-49% or >49%). Appropriate statistical tests were used to compare the variables and significant findings reported. Results: There were 86 cases with isolated RCVS and 44 cases of overlap. Seizures (19, 43%) and encephalopathy (13, 30%) were common in the overlap group, whereas headache was common in the isolated RCVS group (79, 92%). Immunosuppressant use was more often present in the overlap group (9, 20%), but there were no differences in antidepressant, cocaine, or marijuana use. Intracerebral hemorrhage was more common in the overlap group (12/44, p=0.003), but there were similar numbers of ischemic strokes and subarachnoid hemorrhages. There were no differences in the number or location of segments involved or stenosis severity between the groups. Home discharge was more frequent among pure RCVS (73, 85%) than among overlap patients (27, 61%, p=0.004). Conclusion: Clinical presentations and short-term prognosis differed among isolated RCVS and group with PRES-RCVS overlap characteristics. There was no difference in vascular involvement between the groups.

Introduction: Posterior reversible encephalopathy syndrome (PRES) is a clinical syndrome with typical neuroimaging findings of vasogenic cerebral edema in posterior brain regions. Reversible cerebral vasoconstriction syndrome (RCVS) is diagnosed when there is reversible cerebral vessel narrowing and often with thunderclap headache. The two diseases have overlap in clinical and radiographic features. Objective: To compare clinical presentation, vascular abnormalities and imaging findings among PRES and RCVS. Methods: We searched patients in electronic health record at a single tertiary center from January 2008 to December 2018. Inclusion criteria was 18 years or older with clinical and radiographic evidence of PRES or RCVS. PRES was diagnosed by clinical presentation and presence of vasogenic edema on radiographic imaging. RCVS was determined by clinical presentation and transient arterial stenosis. Patient demographics, presenting symptoms, comorbid conditions, and imaging findings were compared between PRES and RCVS populations. Analysis was performed using Fisher’s exact test Results: Seventy-four patients with PRES and 24 patients with RCVS met inclusion criteria. The median age and presenting blood pressure did not differ between PRES and RCVS groups. PRES population consisted of fewer females (70%) compared to RCVS (92%, p=0.05). There was no significant difference in frequency of DWI lesions in PRES (37%) and RCVS (24%, p=0.308). Among patients who had arterial imaging, arterial stenosis was seen in 28% (13/46) of PRES. The occurrence of &gt; 50% FLAIR reversibility was more common in PRES (67%) and seen less frequently in RCVS (27%, p=0.008). Conclusion: There is radiographic overlap between PRES and RCVS. About a quarter of PRES have arterial stenosis, while about a quarter of the RCVS group had FLAIR reversibility.