1. Seniór Epidemiologist Department of ‘Medical Informatics, Epidemiology and Statistics, University of Nijmegen. PO Box 9101,6500 The Netherlands
2. Professor of Epidemiology FonsGabreëls Interdisciplinary Centre for Paediatric Neurology. University of Nijmegen, PO Box 9101,0500 HB Nijmegen. The. Netherlands