Two days after delivery for eclampsia, a 23-year-old woman reports she cannot see. Her pupils are equal and react normally to light, fundoscopy is normal, and there is no evidence of retinal detachment. Brain MRI shows vasogenic oedema in bilateral occipital and parietal white matter. What is the diagnosis?

• A Posterior reversible encephalopathy syndrome ✓
• B Retinal artery embolism
• C Occipital lobe haemorrhage
• D Sheehan syndrome

Explanation

Cortical blindness in severe pre-eclampsia and eclampsia results from posterior reversible encephalopathy syndrome (PRES), where failed autoregulation under extreme hypertension causes vasogenic oedema in the occipital and parietal lobes. The key discriminators here are normal pupillary reactions and a normal fundus, which exclude ocular causes, plus the typical MRI pattern of white matter oedema. PRES resolves with blood pressure control and magnesium therapy, hence the term reversible. Occipital haemorrhage would show blood on MRI, and Sheehan syndrome causes pituitary necrosis with endocrine failure, not cortical visual loss.

Reference: Williams Obstetrics, 26th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.