Bilateral radiological presentation in Rasmussen´s encephalitis with good surgical outcome

Abstract

Case presentation: A 4-year-old and 5-month-old child with a history of sudden onset of clonic seizures that started in the left hallux and progressed to the ipsilateral hemibody and face, lasting up to five minutes. After that, she presented walking and learning difficulty and was unable to perform everyday activities (drawing, writing), which evolved in five months. Electroencephalogram (EEG): diffuse slowing predominating in the right hemisphere; very frequent, almost continuous bilateral interictal epileptiform activity in frontocentroparietal regions mainly on the right. Brain magnetic resonance imaging showed right hemispheric atrophy, with predominantly frontoparietal cortical thinning and reduced brainstem volume on the right, in addition to a nonspecific signal alteration in the left thalamic-mesencephalic area, with possible inflammatory or demyelinating origin. She received CBZ and LEV without seizure control. Cerebrospinal fluid analysis was unremarkable including autoantibodies. At age 5-year-old and 2-month-old she developed progressive left hemiparesis. She received two cycles of pulse therapy (methylprednisolone 30 mg/kg for three days), without significant improvement, with continuous clonic seizures in left hallux. Video-EEG revealed right sided epileptiform activity with midline involvement. At age 6-year-old and 8-month-old the child underwent right hemispherotomy and has been seizure free since then, presenting left hemiparesis and taking clobazam, LEV, ESM and CBZ. Histopathology revealed signs of Rasmussen’s encephalitis (RE), with frequent microglial nodules and perivascular lymphocytic infiltrate, and some lymphocytes surrounding neurons. Discussion: Bilateral brain disease in RE is debated, but it is probably very rare. Only two out of 200 published cases had evidence of bilateral disease. Conclusion: Although rare, the possibility of bilateral involvement in RE should be considered to stress early surgical treatment and to improve outcome.