Rasmussen’s encephalitis is characterized by treatment-resistant focal episodes and is generally observed during childhood, rarely occurring in adults. An 83-year-old man with involuntary contractions in his left arm and leg was brought to emergency care. Patient was conscious during diagnosis, displaying contractions, and Babinski reflex-positive on his left side. Biochemical parameters were within normal values. Dizepam treatment applied in emergency care did not show positive results. A hypodensity was diagnosed in the right brain hemisphere via CT. The patient’s EEG could not be evaluated due to intense artifact movements. During this process, midazolam infusion was applied. Parenteral valproic acid treatment was applied, and dose was incrementally increased to 2000 mg/day. With no results, dose was incrementally increased to 3000 mg/ day with the addition of levetiracetam. Extensive T1 and T2 hypointensity was observed, without any contrasts, in the total right hemisphere via MRI during the episode. Cortical diffusion restriction was observed in diffusion-weighted imaging. The patient was determined to be positive for Rasmussen’s encephalitis with the diagnosis of antiepileptic epilepsia partialis continua in the clinic. An initial treatment of IV immunoglobulin (0.4 mg/kg/day) was initiated, and episodes gradually decreased and finally ended within 3 days. IV immunoglobulin treatment was completed in 5 days. No recurrence was observed. While Rasmussen’s encephalitis is rarely seen in older adults, complete control was achieved with IV immunoglobulin in the present case.

Keywords: Elderly, intravenous immunoglobulin therapy, Rasmussen’s encephalitis