1. Department of Neurosurgery, Medical University of Gdansk, Gdansk, Poland
2. Department of Neurosurgery, Medical University of Lodz, Lodz, Poland
3. Institute of Medicine, Opole University, Opole, Poland,
4. Division of Neurosurgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, United States,
5. Department of Neurosurgery, Pomeranian Medical University, Szczecin,
6. Department of Neurosurgery, Polish Mother Memorial Research Institute, Poland
7. Department of Neurosurgery and Neuro-oncology, Medical University of Lodz, Lodz, Poland.