Methotrexate-induced acute encephalopathy in children：MRI findings and clinical features / 中华放射学杂志

ABSTRACT

Objective To evaluate the MRI findings and clinical features of methotrexate-induced acute encephalopathy in children.Methods The clinical data and brain MRI obtained in 13 children with methotrexate-induced acute encephalopathy were retrospectively reviewed.The MRI features were analyzed , including information on the location , the signal intensity and follow-up MRI study was performed.Results Of the 13 patients , 2 patients suffered from seizure.Five patients had dysphasia , of which 4 patients had evidence of hemiparesis , 1 patient had right facial palsy.Five patients had unilateral weakness.And left hemiparesis was observed in 1 patient.DWI revealed well demarcated asymmetrical hyperintensity lesions within the centrum semiovale and/or periventricular white matter in 10 patients, corresponding to areas of hypointensity on ADC maps.One case showed hyperintensity areas in the bilateral supratentorial cortex and subcortical white matter on T 2-weighted images with subtle high-intensity on DWI.In all 10 cases there were resolution of the diffusion abnormality , 8 cases displayed residual FLAIR signal abnormalities involving areas of previously seen diffusion restriction , 5 cases showed decreased range of the lesion , 1 case was progressive, and 2 cases were stable.One case with hyperintensity areas in the supratentorial cortex and subcortical white matter showed small residual hyperintensity on T 2-weighted images and resolution of the diffusion abnormality.Conclusions MTX-induced acute encephalopathy often manifests as stoke-like symptoms.DWI is the imaging modality of choice for the detection of acute MTX neurotoxicity , and asymmetrical restricted diffusion in the deep white matter is the characteristic sign.Cytotoxic edema induced by MTX is transient and reversible .