Posterior Reversible Encephalopathy Syndrome (PRES)

This is 27 year old female, post partum with PIH with visual blurrring as the presentation.  MRI brain shows multiple T2/FLAIR hyperintensities in the bilateral parietal  & temporo-occipital regions. Diagnosis- PRES. Contributors: Dr Sumer Sethi, Dr Swati Shah, Dr Ajay Garg, Dr Gaurav Singla ( Neurologist)

Also called Reversible Posterior LeukoencephalopathySyndrome.

• Presents with headache, altered consciousness, visual disturbances and/or seizures typically in the setting of new-onset hypertension.
• Associated with acute hypertensive encephalopathy, eclampsia and cytotoxic/ immunosuppressive drugs..
• Etiology unclear, thought to be secondary to endothelial damage in the setting of hypertension and failure of cerebrovascularautoregulationwith subsequent vasogenicedema. The posterior circulation is more sensitive to the effects of hypertension.

MRI

􀂄Multifocal T2-hyperintensities
􀂄 Favors parietal and occipital cortex (nearly 100% of cases), butcan involve other cortex, thalamus, basal gaglia, cerebellum and brainstem.
􀂄 Variable presentation on diffusion weighting imaging. Ischemic changes on DWI/ADC are associated with worse prognosis.