Neurosurgery, or neurological surgery is the medical specialty concerned with the prevention, diagnosis, surgical treatment, and rehabilitation of disorders which affect any portion of the central nervous system including the brain, spinal cord, peripheral nerves, and cerebrovascular system. The most common condition that neurosurgeons treat is pain in the neck or back spreading to the arm or leg due to a ruptured disc or spinal stenosis, a narrowing of the open spaces within your spine, which can put pressure on the spinal cord and the nerves that travel through the spine to arms and legs.