1. Department of Neurosurgery, Thomas Jefferson University, Jefferson Hospital for Neuroscience, Philadelphia, PA, USA
2. Department of Neurological Surgery, University of Virginia School of Medicine, Charlottesville, VA, USA
3. Department of Neurosurgery, University of Iowa, Iowa City, IA, USA
4. Division of Neurovascular Surgery and Endovascular Neurosurgery, Department of Neurological Surgery, Thomas Jefferson University Hospital, 901 Walnut Street 3rd Floor, Philadelphia, PA 19107, USA