Cytotoxic Edema in Posterior Reversible Encephalopathy Syndrome: Correlation of MRI Features with Serum Albumin Levels

Abstract

Background and purpose: Posterior reversible encephalopathy syndrome is a clinicoradiologic entity with typical MR imaging showing predominant vasogenic and occasional cytotoxic edema. It is unclear whether MR imaging correlates with levels of serum albumin. We determined potential risk factors for development of cytotoxic edema in posterior reversible encephalopathy syndrome.

Materials and methods: Seventy-nine cases with typical clinical symptoms and characteristic neuroradiologic findings conformed to posterior reversible encephalopathy syndrome diagnostic criteria and were included in this study. FLAIR, DWI, and ADC maps were interpreted to evaluate the severity and type of edema. MR imaging was correlated with the levels of serum albumin, and cytotoxic edema was compared with the location and severity of brain edema.

Results: Pure vasogenic edema was found in 53 cases (67.09%), and vasogenic edema complicated with cytotoxic components, in 26 patients (32.91%). There was no difference in serum albumin levels between patients with cytotoxic components and those with vasogenic edema (P = .983). There was a significant difference in the edema scale scores between patients with cytotoxic edema and those with vasogenic edema (P = .006). The percentage of cytotoxic edema located in the area with higher scale scores of edema was significantly larger than that in areas with lower scale scores of edema (P = .002).

Conclusions: Serum albumin may contribute to the development of edema in PRES but is not a decisive factor for edema type. Cytotoxic edema in posterior reversible encephalopathy syndrome is probably related to regional decreased perfusion and arteriolopathy. Further work should be undertaken to discover the pathophysiologic mechanisms involved.

© 2015 by American Journal of Neuroradiology.

Figures

Fig 1.

Comparison of serum albumin levels between patients with PRES with cytotoxic edema and those only with vasogenic edema. A, A 26-year-old pregnant woman presented with eclampsia, with a serum albumin level of 37 mg/dL. Hyperintense abnormalities are found in bilateral frontoparietal lobes on FLAIR (left), hyperintense on DWI (middle) and hypointense on ADC (right), and are also noted in the right parietal lobe, indicating cytotoxic edema. B, A 22-year-old woman with systemic vasculitis with a serum albumin level of 34.2 mg/dL and blood pressure of 175/110 mm Hg at onset. Symmetric hyperintensities are found in the bilateral frontoparietal lobes on FLAIR (left), isointense on DWI (middle) and hyperintense on ADC (right), indicating vasogenic edema.

Fig 2.

Comparison of the scores of brain edema between patients with PRES with cytotoxic edema and those only with vasogenic edema. A, A 25-year-old woman with eclampsia and seizures after cesarean delivery. FLAIR image shows symmetric confluent heterogeneous hyperintensities in the bilateral, frontal, and parietal lobes (left) with a scale score 3 of edema severity and marked hyperintensity in the adjacent cortex on DWI (middle), with hypointensity on the ADC map (right), indicating cytotoxic edema. B, A 27-year-old man with hypertension and nephritis had headache with blood pressure of 180/120 mm. Symmetric hyperintensities are found in the bilateral occipital lobes on FLAIR (left) with a scale score 1 of edema severity, isointense on DWI (middle) and hyperintense on ADC (right), indicating vasogenic edema.