Prevalence and Risk Factors of Posterior Reversible Encephalopathy Syndrome in Isfahan, Iran

Posterior reversible encephalopathy syndrome (PRES) is a rare clinical-radiological syndrome characterized by such symptoms as headaches, altered consciousness, blurred vision, seizure, and focal neurological deficits. We herein present well-documented PRES cases and discuss the risk factors and characteristic imaging patterns of this syndrome. We prospectively examined 31 patients with PRES in Alzahra Hospital, Isfahan, Iran, and compared the underlying diseases of PRES in terms of their clinical features and cranial magnetic resonance imaging (MRI) findings. The most common underlying disease was hypertension (90.3%), followed by systemic lupus erythematosus (32.3%), preeclampsia (25.8%), chronic renal failure (22.6%), and rheumatoid arthritis (22.6%). Interestingly, we also reported heroin abuse as a possible risk factor for PRES (9.7%). The most frequent clinical signs were headaches (54.8%), seizure (54.8%), and blurred vision (35.5%). The most frequent lesions on cranial MRI were in the parieto-occipital area (87.1%), followed by the cerebellum (19.4%) and the frontal lobe (12.9%). Other abnormalities on MRI were less common. In addition, 16.1% of the study population had vasospasm on magnetic resonance arteriography (MRA). Clinical recovery was followed by radiological resolution in all the patients. The clinical presentation is nonspecific, most patients present with a combination of symptoms, particularly headaches and seizure. MRI is crucial for the diagnosis of PRES, and MRA is useful in that it can identify associated vasospasm. Timely diagnosis and treatment are required to avoid a devastating outcome.