Hemorrhage in posterior reversible encephalopathy syndrome: imaging and clinical features

Abstract

Background and purpose: Hemorrhage is known to occur in posterior reversible encephalopathy syndrome (PRES), but the characteristics have not been analyzed in detail. The purpose of this study was to evaluate the imaging and clinical features of hemorrhage in PRES.

Materials and methods: Retrospective assessment of 151 patients with PRES was performed, and 23 patients were identified who had intracranial hemorrhage at toxicity. Hemorrhage types were identified and tabulated, including minute focal hemorrhages (<5 mm), sulcal subarachnoid hemorrhage, and focal hematoma. Clinical features of hemorrhage and nonhemorrhage PRES groups were evaluated, including toxicity blood pressure, coagulation profile/platelet counts, coagulation-altering medication, and clinical conditions associated with PRES. Toxicity mean arterial pressure (MAP) groups were defined as normal (<106 mm Hg), mildly hypertensive (106-116 mm Hg), or severely hypertensive (>116 mm Hg).

Results: The overall incidence of hemorrhage was 15.2%, with borderline statistical significance noted between the observed clinical associations (P = .07). Hemorrhage was significantly more common (P = .02) after allogeneic bone marrow transplantation (allo-BMT) than after solid-organ transplantation. The 3 hemorrhage types were noted with equal frequency. A single hemorrhage type was found in 16 patients, with multiple types noted in 7. Patients undergoing therapeutic anticoagulation were statistically more likely to develop hemorrhage (P = .04). No difference in hemorrhage incidence was found among the 3 blood pressure subgroups (range, 14.9%-15.9%).

Conclusions: Three distinct types of hemorrhage (minute hemorrhage, sulcal subarachnoid hemorrhage, hematoma) were identified in PRES with equal frequency. The greatest hemorrhage frequency was seen after allo-BMT and in patients undergoing therapeutic anticoagulation. Hemorrhage rate was independent of the toxicity blood pressure.

Fig 1.

A 27-year-old man with necrotic pneumonia and lung abscess. A, MR FLAIR image demonstrates PRES vasogenic edema in the parietal and frontal lobes (arrows). B, Gradient image demonstrates minute hemorrhages in the left frontal lobe (arrows).

Fig 2.

A 50-year-old woman with fever and severe hypertension. A and B, FLAIR MR image demonstrates sulcal signal abnormality and PRES vasogenic edema in the left frontal lobe (arrowheads) and edema in the occipital lobes bilaterally (open arrows). C, Gradient MR image demonstrates linear low signal intensity consistent with sulcal subarachnoid hemorrhage (arrows). D, CT image demonstrates high attenuation consistent with the MR imaging appearance, further confirming the sulcal subarachnoid hemorrhage (arrow).

Fig 3.

A 50-year-old man status post allo-BMT for acute myelogenous leukemia. CT scan demonstrates PRES vasogenic edema in the parietal region bilaterally (arrowheads), along with an acute hematoma in the left parietal lobe (arrow).