1. Department of Neurosurgery, Irkutsk State Medical University, Irkutsk, Russia;
2. Department of Neurosurgery, Railway Clinical Hospital, Irkutsk, Russia;
3. Department of Traumatology, Orthopedic and Neurosurgery, Irkutsk State Medical Academy of Postgraduate Education, Irkutsk, Russia;
4. Department of Neurosurgery, Rutgers New Jersey Medical School, Newark, New Jersey, USA