Reversible corpus callosum splenial lesion due to steroid therapy.

Reversible corpus callosum splenial (CCS) lesions are rare findings and usually detected incidentally. We presented a case of 15-year-old boy with a diagnoses of nephrotic syndrome. He was referred for neuropsychiatric symptoms following dose reduction on steroid treatment. Brain magnetic resonance imaging (MRI) revealed a focal lesion in the CCS, hyperintense on T2 and FLAIR and hypointense on T1 images with diffusion restriction on apparent diffusion coefficient map. Follow-up MRI 3 weeks later showed complete resolution of the lesion. It was probably result of focal intramyelinic edema due to excytotoxic mechanisms and/or arginine-vasopressin release.