The many faces of posterior reversible encephalopathy syndrome

Abstract

The classic imaging findings of posterior reversible encephalopathy syndrome (PRES) are of bilateral parietal and occipital subcortical vasogenic oedema, and are well established in the literature. As experience with PRES grows, varied and atypical presentations are being increasingly described. This pictorial review illustrates the variable presentations of PRES, including cases with atypical imaging findings. We illustrate cases of PRES with varying distributions of vasogenic oedema as well as cases with atypical imaging findings, such as variations of haemorrhage and restricted diffusion. Atypical imaging findings should not dissuade the diagnosis of PRES in the appropriate clinical situation, and knowledge of the varied appearance and atypical findings of PRES allows the radiologist to make this diagnosis.

Figure 1

A 29-year-old female with systemic lupus erythematosus and lupus nephritis, recently started on cyclosporine. She presented with new-onset visual changes and headache, progressing to seizure. (a–c) Brain MRI [fluid attenuated inversion recovery (FLAIR) sequence] obtained on the day of presentation demonstrates moderate vasogenic oedema in the subcortical white matter of the parietal and occipital regions. (d–f) Brain MRI (FLAIR sequence) performed 7 days later demonstrates resolution of the vasogenic oedema seen on the previous MR study.

Figure 2

A 61-year-old male presenting with tonic–clonic seizures, progressing to coma. (a–c) Brain MRI [fluid attenuated inversion recovery (FLAIR) sequence] obtained on the day of presentation demonstrates marked vasogenic oedema involving subcortical, deep and periventricular white matter of the frontal, parietal and occipital regions, while maintaining a predominant posterior pattern. (d–f) Brain imaging (FLAIR sequence) performed 6 days later demonstrates improvement of the vasogenic oedema.

Figure 3

A 61-year-old female with recent liver transplantation on tacrolimus therapy with new-onset fluent aphasia. (a–c) Brain MRI (fluid attenuated inversion recovery sequence) demonstrated unilateral moderate vasogenic oedema in the white matter of the left posterior temporal, parietal and occipital regions.

Figure 4

A 23-year-old female with systemic lupus erythematosus presenting with new-onset seizures. (a–c) Brain MRI (fluid attenuated inversion recovery sequence) obtained on the day of presentation demonstrates vasogenic oedema in the posterior limb of the right internal capsule, extending into the adjacent corona radiata, and subcortical white matter of both parietal lobes. (d, e) Selective digital subtraction angiogram of the left vertebral artery demonstrated multiple areas of vessel calibre irregularity in the secondary and tertiary branches of the left and right posterior cerebral arteries.

Figure 5

A 31-year-old male intravenous drug abuser found unconscious. Blood pressure at presentation was 180/110 mmHg. (a–d) Brain MRI [fluid attenuated inversion recovery (FLAIR) sequence] demonstrated marked vasogenic oedema in the white matter of the parietal and occipital regions, most severe in the cerebellum, with resultant obstructive hydrocephalus. (e–h) Brain MRI (FLAIR sequence) performed 6 weeks later demonstrates resolution of the vasogenic oedema seen on the previous MR study.

Figure 6

A 39-year-old male with an appendiceal carcinoid tumour treated with chemotherapy complicated by haemolytic uraemic syndrome. Systolic blood pressure at the time of the study was >220 mmHg. (a–d) Brain MRI (fluid attenuated inversion recovery sequence) demonstrates numerous foci of vasogenic oedema in the occipital regions, cerebellum and brain stem. A large haematoma is seen in the left temporal lobe. (e) Proton density image demonstrates a haematoma in the left temporal lobe. (f) Non-contrast CT again demonstrates the known haematoma with surrounding vasogenic oedema.

Figure 7

A 70-year-old with metastatic hepatocellular carcinoma presenting with new-onset seizures 7 days after commencing a trial chemotherapeutic agent, brivanib. (a–c) Brain MRI (fluid attenuated inversion recovery sequence) demonstrates vasogenic oedema in the subcortical and deep white matter of the parietal and occipital regions. (d–g) T₂* gradient sequence demonstrates subarachnoid haemorrhage in the interhemispheric fissure, right ambient cistern and occipital horn of the left lateral ventricle.

Figure 8

An 87-year-old female presenting with a 15 min episode of visual changes and slurred speech. Blood pressure at the time of presentation was 176/99 mmHg. (a–d) Brain MRI (fluid attenuated inversion recovery sequence) demonstrates vasogenic oedema in the subcortical white matter of the left post-central gyrus, the right parietal lobe, right temporal lobe and bilateral occipital lobes. (e–g) T₂* gradient sequence demonstrates haemosiderin in a petechial cortical gyral distribution.

Figure 9

A 65-year-old female with thrombotic thrombocytopenic purpura presenting with acute renal failure and generalised seizures. Her systolic blood pressure was 200 mmHg at presentation. (a) Brain MRI (fluid attenuated inversion recovery sequence) demonstrates vasogenic oedema in the white matter of the occipital lobes. (b) Diffusion-weighted imaging and (c) apparent diffusion coefficient map demonstrate a region of restricted diffusion in the right occipital cortex.

Figure 10

A 30-year-old male with uncontrolled hypertension presenting with a 2-week history of paroxysmal headaches and visual changes. His blood pressure was 198/120 mmHg on presentation. (a, b) Brain MRI with (a) T₂ and (b) fluid attenuated inversion recovery sequence demonstrated white matter vasogenic oedema in the occipital lobes. (c) Diffusion-weighted imaging and (d) apparent diffusion coefficient map demonstrated a transient splenial lesion, a region of reversible restricted diffusion in the splenium of the corpus callosum. This resolved on subsequent imaging (not shown).