Transient widespread cortical and splenial lesions in acute encephalitis/encephalopathy associated with primary Epstein-Barr virus infection. 
Infection with Epstein-Barr virus (EBV) is very common and usually occurs in childhood or early adulthood.  Encephalitis/encephalopathy is an uncommon but serious neurological complication of EBV.  A case of EBV-associated encephalitis/encephalopathy with involvement of reversible widespread cortical and splenial lesions is presented herein.  An 8-year-old Chinese girl who presented with fever and headache, followed by seizures and drowsiness, was admitted to the hospital.  Magnetic resonance imaging revealed high signal intensities on diffusion-weighted imaging in widespread cortical and splenial lesions.  The clinical and laboratory examination results together with the unusual radiology findings suggested acute encephalitis/encephalopathy due to primary EBV infection.  After methylprednisolone pulse therapy together with ganciclovir, the patient made a full recovery without any brain lesions.  The hallmark clinical-radiological features of this patient included severe encephalitis/encephalopathy at onset, the prompt and complete recovery, and rapidly reversible widespread involvement of the cortex and splenium.  Patients with EBV encephalitis/encephalopathy who have multiple lesions, even with the widespread involvement of cortex and splenium of the corpus callosum, may have a favorable outcome with complete disappearance of all brain lesions.