Atypical Edema in Posterior Reversible Encephalopathy Syndrome: Clinical Associations and Outcome

Area of Science:

• Neurology
• Radiology
• Neuroimaging

Background:

• Posterior reversible encephalopathy syndrome (PRES) is a neurotoxic condition with distinct imaging features.
• Classic PRES involves parieto-occipital edema, but atypical presentations can include varied involvement of deep gray nuclei, brainstem, cerebellum, and corpus callosum, complicating diagnosis.

Purpose of the Study:

• To characterize the neuroimaging features of atypical PRES in a large patient cohort.
• To evaluate the relationships between atypical PRES imaging findings, clinical variables, and patient outcomes.

Main Methods:

• Retrospective analysis of neuroimaging data from 184 patients diagnosed with PRES.
• Identification of cases with atypical edema patterns on MRI.
• Assessment of relationships between MRI findings, clinical variables, and outcomes using regression analyses.

Main Results:

• 71.7% of PRES cases exhibited atypical imaging findings.
• Atypical edema was associated with older age (≥52 years) and negatively associated with pregnancy.
• Certain atypical edema patterns correlated with prolonged hospital stays and reduced clinical reversibility.

Conclusions:

• Atypical neuroimaging findings are frequent in PRES, occurring in over 70% of cases in this cohort.
• Atypical PRES, especially with posterior circulation involvement, is more common in older patients and less common in pregnancy, potentially indicating a more severe disease form.
• Identifying atypical PRES imaging patterns is vital for prompt diagnosis, intervention, and improving patient outcomes.