1. Department of Neurology, Julius-Maximilians Universität Würzburg, Würzburg, Federal Republic of Germany
2. Department of Neurosurgery, Julius-Maximilians Universität Würzburg, Würzburg, Federal Republic of Germany
3. Department of Neuroradiology, Julius-Maximilians Universität Würzburg, Würzburg, Federal Republic of Germany