9. Trial sites Potential study participants are referred to our department (Dept. of Epileptology, University of Bonn) from all over Germany. The study procedures, especially the clinical and neuroradiological follow-up studies including assessment of safety parameters are performed in Bonn (visits every two months within the first year, in the second year every four months, thereafter every six months). In the intervals between the visits in Bonn, the referring centers participate in monitoring of the patients and administration of IVIG. There is continuous contact between the study center Bonn and the external study co-workers.