Clinical and imaging characteristics of posterior reversible encephalopathy syndrome in children with acute lymphoblastic leukemia after chemotherapy induction

Objective To investigate the clinical features, brain imaging significance and the possible pathogenesis of posterior reversible encephalopathy syndrome (PRES) in childhood acute lymphoblastic leukemia (ALL) followed by chemotherapy induction. Methods The diagnosis and treatment of ALL were performed according to the guidelines of the Pediatric Association of Chinese Medical Association.There were 11 cases of pediatric ALL who deve-loped PRES after chemotherapy induction.The clinical presentations, initial and follow-up radiologic features, and the neurologic outcomes of these 11 cases were investigated for one-year follow-up.All patients were reexamined 1, 3, 6, and 12 months after first imaging. Results Headache (10/11 cases), epileptic seizure (7/11 cases), high blood pressure (4/11 cases), visual impairment (6/11 cases), disturbance of consciousness (5/11 cases) and walking instability (2/11 cases) were the most common symptoms of these ALL patients with PRES.Magnetic resonance imaging (MRI) scanning revealed that lesions were mainly distributed in occipital lobe (9/11 cases), parietal lobe (8/11 cases), frontal lobe (5/11 cases), temporal lobe (3/11 cases), the deep white matter of bilateral periventricular and centrum se-miovale (2/11 cases) and hemisphaerium cerebelli (1/11 cases). The radiological findings indicated that lesions had multifocal, symmetrical and posteriorly distributed characteristics in the cerebral hemispheres.After the diagnosis of PRES, patients stopped chemotherapy courses promptly and received symptomatic treatment, and then the clinical and imaging symptoms of most cases gradually disappeared.After 1-year follow-up, 9 patients had good prognosis and no sequelae, 1 patient had symptomatic epilepsy (brain magnetic resonance imaging scan showed lesions in the left temporal lobe), and 1 patient had slight visual impairment.After the craniocerebral symptoms disappeared clinically ALL chemotherapy continued in all patients and no recurrent PRES was observed. Conclusions Although the clinical and imaging features of PRES may be diverse, PRES should be recognized as a possible important complication of ALL when neurological symptoms appear.However, PRES is reversible when the patients are diagnosed and treated at an early stage.Thus, the occurrence of PRES should be considered and investigated to optimize the early induction schemes for ALL treatment. Key words: Posterior reversible encephalopathy syndrome; Magnetic resonance imaging; Chemotherapy induction; Acute lymphoblastic leukemia; Child