1. Department of Neurological Surgery, Oregon Health & Science University, Portland, Oregon, USA;
2. Department of Surgery, Oregon Health & Science University, Portland, Oregon, USA;
3. School of Medicine, Oregon Health & Science University, Portland, Oregon, USA;
4. Department of Pathology, Oregon Health & Science University, Portland, Oregon, USA;
5. Department of Neurological Surgery, University of Arizona, Tuscon, Arizona, USA;
6. Department of Neurological Surgery, Stanford Medicine, Palo Alto, California, USA