1. Departments of Neurologic and Orthopedic Surgery; Mayo Clinic; Rochester Minnesota
2. Department of Anatomical Sciences; School of Medicine, St George's University; Grenada West Indies
3. Department of Medicine; University of Nevada SOM; Las Vegas Nevada
4. Section of Pediatric Neurosurgery; Children's Hospital Birmingham Alabama
5. Department of Anatomy; Medical School Varmia and Mazuria; Olsztyn Poland