Abstract: Objective　Posterior reversible encephalopathy syndrome (PRES) is a neurological complication associated with chemical agents. This study is to investigate clinical characteristics and radiological features of this disease. Methods Demographic and medical data of all acute lymphoblastic leukemia patients who had radiological and clinical manifestations consistented with PRES between September 2015 and September 2018 were retrospectively analyzed. Results　Among 582 patients with acute lymphoblastic leukemia, a total of 9 patients were included and 7 patients received pegaspargase therapy before PRES. Five patients had acute hypertension before PRES. Seizure was the most common clinical manifestation, followed by myasthenia and paresthesia. In brain magnetic resonance imaging, parietal and occipital lobes were found to be involved in six (60%) patients and other involvements including temporal lobes, frontal lobes, cerebellum, brainstem, thalamus and basal ganglia. Hyponatremia was observed in six (60%) patients, while six (60%) patients suffered from hypofibrinogenemia. Conclusions Pegaspargase, intensive chemotherapy, intrathecal therapy and acute hypertension were risk factors for PRES development. hyponatremia and hypofibrinogenemia may indicate the development of PRES.

Key words: acute lymphoblastic leukemia;　posterior reversible encephalopathy syndrome;　hyponatremia;　 hypofibrinogenemia;　child