Teodor Svedung Wettervik1, Per Enblad2. 1. Section of Neurosurgery, Department of Neuroscience, Uppsala University, 751 85, Uppsala, Sweden. teodor.svedung-wettervik@neuro.uu.se. 2. Section of Neurosurgery, Department of Neuroscience, Uppsala University, 751 85, Uppsala, Sweden.