A 39-year-old Para 1 with known idiopathic generalised epilepsy presented at term with a short history of vomiting and visual disturbance. She was subsequently identified as having borderline hypertension with deranged renal and liver function suggesting possible pre-eclampsia. Labour was induced. In the 24 h following delivery, she developed symptoms of confusion, ataxia and diplopia. Initial head CT reported as normal. Renal, Gastroenterology and Neurology specialists reviewed and a number of diagnoses considered, including hepatic encephalopathy, infection, eclampsia and epilepsy. IV haloperidol was required. She was transferred to the Intensive Care Unit for sedation and IV Magnesium. A diagnosis of PRES was considered and head MRI was performed. This showed evidence of ischaemic changes to the brain stem and cerebellum On Day 6 she was transferred to Neurology, where she was noted to have seizure activity and dosage of anti-epileptics was increased. On Day 10 she was discharged, no longer confused but with some ataxia. Subsequent follow-up by Neurology with a repeat MRI head was normal.

PRES is described as an abnormal neurological state combined with reversible MRI changes in the parieto-occipital regions of the brain, the pathophysiology of which is a form of vasogenic oedema seen in pregnancy as a variant of pre-eclampsia.. There is a spectrum of clinical presentations but PRES is important to recognise and treat in order to prevent long-term neurological deficit.