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Reversible Encephalopathy Syndrome
Case Detail
| Anatomy: Brain-Spine |
 Joseph Junewick, MD FACR |
| Diagnostic Category: Metabolic |
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| Created: over 2 years ago |
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| Updated: over 2 years ago |
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| Tags:
PEDS
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| Modality/Study Types:
MR
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Activities:  PDF  ImageJA |
History
4 year old with new onset seizure 3 days into treatment of acute lymphoblastic leukemia with vincristine, decadron and allopurinol.
Case Images
Diagnosis
Reversible Encephalopathy Syndrome
Clinical Notes
On initial admission – Abnormal liver function tests (elevated bilirubin, alkaline phosphatase, lactate dehydrogenase, AST, and ALT) and pancytopenia.
6 month followup MRI – Negative
Findings
MR – Axial T2 and T2-FLAIR images demonstrate areas of high signal in the cortex and subcortical white matter in a parasagittal distribution.
Discussion
Posterior reversible encephalopathy syndrome (PRES) describes a constellation of symptoms and imaging findings which are transient. Presenting symptoms may abrupt or insidious and may include headache, altered mentation, visual deficits, or seizure. Hyperperfusion and breakthrough of the blood-brain barrier with exudation of fluid, blood and/or macromolecules in the cerebral cortex and subcortical white matter account for the imaging findings; atypical locations of the anterior cerebrum, basal ganglia, brainstem and cerebellum can also be seen.
The posterior circulation is most commonly involved secondary to relative lack of sympathetic innervation of arterioles (autoregulation), but anterior circulation can be variably affected. Signal abnormalities are most conspicuous on T2-FLAIR. Histologic evaluation reveals vasogenic edema without inflammation or ischemia and acute/chronic vessel injury.
Predisposing conditions associated with PRES include eclampsia/pre-eclampsia, hypertension, immunosuppressive therapy, multiagent or high-dose chemotherapy, multisystem failure (in particular hepatic and renal), shock, hypercalcemia, thrombocytopenia syndromes, and autoimmune disorders.
Reference
Bartynski WS. Posterior reversible encephalopathy syndrome, part I: Fundamental imaging and clinical features. AJNR (2008); 29:1036-1042.
McKinney AM, et al. Posterior reversible encephalopathy syndrome: Incidence of atypical regions of involvement and imaging findings. AJR (2007); 189:904-912.