Neurosurgery is the medicinal field dealing with the deterrence, analysis, surgical treatment, and rehabilitation of disorders which affects the nervous system including the brain, spinal cord, peripheral nerves, and extra-cranial cerebrovascular system. Neuroanesthesia is major division established in endovascular surgery. Divisions of neurosurgery are: vascular neurosurgery and Endovascular neurosurgery. Certain of these divisions of neurosurgery are stereotactic neurosurgery, epilepsy surgery, endovascular neurosurgery, vascular neurosurgery and, functional neurosurgery; after included some more neurosurgeries they are: partial or total corpus colostomy. Hemispherectomy is the removal of part of the brain.