World Federation of Neurosurgical Societies
http://www.wfns.org

EANS- European Association of Neurosurgical Societies
http://www.eans.org/index-s.html

American Association of Neurological Surgeons
http://www.neurosurgery.org/aans/

Congress of Neurological Surgeons
http://www.neurosurgery.org/cns/