1. Department of Medicine, Hospital of the University of Pennsylvania, PA
2. Department of Neurology, Weill Cornell Medical College, NY
3. Department of Neurosciences, McLaren Bay Neurosurgery Associates, Bay City, Michigan
4. Department of Neurosurgery, Montefiore Medical Center, NY
5. Department of Neurology, Tufts Medical Center, MA
6. Metrohealth Medical Center, Case Western Reserve University School of Medicine, OH