Rasmussen encephalitis (RE) is a rare but severe chronic inflammatory brain disease of unknown origin affecting one brain hemisphere. It is usually accompanied by intractable epilepsy. In addition, it often leads to severe disability due to functional deficits caused by atrophy of one brain hemisphere. Hemispherectomy is an effective means of surgical treatment of the epilepsy. It renders the patient, however, hemiplegic, hemianopic and (if the language dominant hemisphere is affected) aphasic. To slow down or even stop the progressive inflammatory damage to the affected brain hemisphere, immunotherapies may be beneficial. According to a literature survey, tacrolimus (twice daily intake of capsules) and intravenous immunoglobulins (monthly infusions) are the most promising compounds for this. In the investigators' study, these two types of treatment are randomly assigned to patients with disease onset within the last year and not too far advanced disability or hemispheric brain injury. The patients are followed to assess prospectively the functional and brain MRI course of the disease.