1. Department of Neurology and Radiology; University of Pittsburg; Pittsburg Pennsylvania U.S.A
2. Department of Neurology; Yale University School of Medicine; New Haven Connecticut U.S.A.
3. Department of Neurosurgery; Yale University School of Medicine; New Haven Connecticut U.S.A
4. Department of Neurology; Columbia University School of Medicine; New York New York U.S.A
5. Department of Radiology; University of Pittsburgh; Pittsburg Pennsylvania U.S.A