PT - JOURNAL ARTICLE AU - Bo Gao AU - Cui Lyu AU - Alexander Lerner AU - Alexander M McKinney TI - Controversy of posterior reversible encephalopathy syndrome: what have we learnt in the last 20 years? AID - 10.1136/jnnp-2017-316225 DP - 2018 Jan 01 TA - Journal of Neurology, Neurosurgery & Psychiatry PG - 14--20 VI - 89 IP - 1 4099 - http://jnnp.bmj.com/content/89/1/14.short 4100 - http://jnnp.bmj.com/content/89/1/14.full SO - J Neurol Neurosurg Psychiatry2018 Jan 01; 89 AB - Over two decades have passed since posterior reversible encephalopathy syndrome (PRES) was first described in 1996. It has becoming increasingly recognised because of improved and more readily available imaging modality. The exact pathophysiological mechanism is not completely understood and remains controversial at present. Precise diagnosis is essential to guide prompt, proper management. Our ability of differentiating it from other acute neurological disorders is likely to improve as we learnt more about the spectrum of this entity in the last 20 years. We emphasise the importance of recognising its diagnostic criteria and biomarker, which would be of great relevance to either outcome evaluation or study design. PRES has a favourable prognosis generally, but neurological sequelae and even fatalities can occur, especially in severe forms that might cause substantial morbidity and even mortality, particularly when the syndrome is complicated by intracranial haemorrhage or brain infarction. In this review, the pathophysiology, approach to diagnosis, some controversies as to the prognosis, as well as the future research direction of PRES are described.