1. Departments of Neurological Surgery, Los Angeles County/University of Southern California Medical Center and University of Southern California School of Medicine, Los Angeles, California
2. Departments of Neuroradiology, Los Angeles County/University of Southern California Medical Center and University of Southern California School of Medicine, Los Angeles, California
3. Departments of Pathology, Los Angeles County/University of Southern California Medical Center and University of Southern California School of Medicine, Los Angeles, California