Introduction:
Posterior reversible encephalopathy syndrome (PRES) is an entity characterized by acute neurological symptoms including headache, quantitative disturbances of consciousness or vision and seizures, accompanied by radiological findings. Most of the time it is induced by high blood pressure in predisposed patients.

Aim:
The aim of the study is to spread the knowledge of PRES and emphasize its risk factors.

Case study:
45-year-old male with a history of hypertension and nephrotic syndrome was admitted to the emergency department after seizure. Although the patient was normotensive, his numerous risk factors were considered and he was diagnosed with PRES. Initial diagnosis was confirmed in MRI.

Results and discussion:
Normotensive patients develop compensatory mechanisms within the central nervous system to ensure constant cerebral blood flow despite blood pressure fluctuations. Abnormal compensatory response in patients with PRES is related to increased permeability of blood vessels and culminates in vasogenic brain oedema, however, chronic hypertension is a relative protective factor in the development of PRES. It is essential to distinguish between PRES, ischaemic cerebral stroke, uremic encephalopathy and cerebral venous sinus thrombosis. The treatment of PRES involves elimination of the predisposing factor and arterial pressure reduction.

Conclusions:
PRES is characterized by symptoms resembling stroke which makes the differential diagnosis difficult. Due to the differences in the management of ischemic stroke and PRES, as well as the time factor, which brings forward the preservation of neurological symptoms in both cases, a prompt and accurate diagnosis followed by urgent implementation of therapeutic procedure in the hospital emergency department is essential.