Learning objectives
To describe the spectrum of imaging findings ofposterior reversible encephalopathy syndrome (PRES) with special focus on the atypical presentations and the prognostic factors.
Background
Etiology
-hypertensive crisis (HTA)
-eclampsia
-cytotoxic-immunosuppressive drugs
-uremic encephalopathies
-other: contrast-induced anaphylaxis,
sudden alcohol withdrawn [1,
2].
Symptoms
-headache,
consciousness alteration,
visual disturbances,
seizures [1,
2].
Radiologic findings
-bilateral cortico-subcortical lesions,
low attenuation on CT,
on MR images hypointense on T1WI and hyperintense on T2WI [1]
-poor prognosis predictorsare: extension of edema,
cytotoxic edema on DWI and presence of hemorrhage [2].
Differential diagnostic
-ischemic events: vascular territory,
clinical findings,
risk factors,
diffusion restriction
-metastasis: multifocal,
cortico-subcortical junction,
enhancement; the 3 most common origins - lung,...
Imaging findings OR Procedure details
PRES has a large spectrum of radiological manifestations,
depending on:
the evolving phase
the celerity of onset of the clinical picture
the quickness in initiating the treatment.
It might present with very atypical findings that can be easilyconfused with other entities.
We present some examples of cases emphasizing on atypical findings:
TYPICAL PRESENTATIONS
Case 1. Hypertensive crisis in a 23-year-old woman,
in theimmediate puerperal period.
Blood pressure 230/135 mmHg.
CT and MRI performed the same day,
depicted subcortical areas of vasogenic edema in the classical...
Conclusion
A prompt suspicion and diagnosis of PRES could lead to a prompt treatment and subsequently to a rapid improvement,
and also to avoid complications and poor outcome.
MRI has an important role inthe assessment of prognostic factorsand complications of PRES.
One of the most incipient imaging manifestations of PRES can be bilateral and symmetrical delay of TTP/MTT on perfusion studies,
simulating ischemic penumbras and being a cause of stroke-mimic.
Perfusion-CT could open a new line of diagnosis of incipient PRES.
References
1.Hinchey J,
Chaves C,
Appignani B,
Breen J,
Pao L,
Wang A,
et al.
A reversible posterior leukoencephalopathy syndrome.
N Engl J Med.1996;334:494-500.
2.Bartynski WS.
Posterior reversible encephalopathy syndrome,
part 1: fundamental imaging and clinical features.
AJNR Am J Neuroradiol.
2008;29:1036-42.
3.McKinney AM,
Short J,
Truwit CL,
McKinney ZJ,
Kozak OS,
Santa Cruz KS,
et al.
Posterior reversible encephalopathy syndrome: incidence of atypical regions of involvement and imaging findings.
AJR.
2007;189:904-12.
4.Okada J,
Yoshikawa K,
Matsuo H,
Kanno K,
Oouchi M.
Reversible MRI and CT...
Personal Information
Nicolae Sarbu - Radiology Department,
Hospital Clinic of Barcelona,
Spain,
[email protected]