S
SACCULAR (BERRY) ANEURYSM - Sac-like bulging on one side of an artery. Usually arises at an arterial branching.
SACRUM - Part of the spine that is also part of the pelvis. It articulates with the ilia at the sacroiliac joints and articulates with the lumbar spine at the lumbosacral joint. The sacrum consists of five fused vertebrae that have no intervertebral discs.
SAGITTAL - Longitudinal.
SCIATICA - A term indicating pain along the course of a sciatic nerve, especially noted in the back of the thigh and below the knee.
SCOLIOSIS - Lateral (sideways) curvature of the spine.
SCOTOMA - An area of decreased vision surrounded by an area of less depressed or normal vision.
SEPSIS - A state of infection of tissue due to disease-producing bacteria or toxins.
SEPTUM - A thin wall dividing two cavities or masses of softer tissue.
SHUNT - A tube or device implanted in the body, usually made of silastic, to redivert excess CSF away from the brain to another place in the body.
SKELETON - The rigid framework of bones that gives form to the body, protects and supports the soft organs and tissues, and provides attachments for muscles.
SPINA BIFIDA - A congenital defect of the spine marked by the absence of a portion of the spine.
SPINAL CANAL - The bony channel that is formed by the intravertebral foramen of the vertebrae and in which contains the spinal cord and nerve roots.
SPINAL COLUMN - See spine.
SPINAL CORD - The longitudinal cord of nerve tissue that is enclosed in the spinal canal. It serves not only as a pathway for nervous impulses to and from the brain but as a center for carrying out and coordinating many reflex actions independently of the brain.
SPINAL DISC - See disc.
SPINAL FUSION - Operative method of strengthening and limiting motion of the spinal column. Can be performed with a variety of metal instruments and bone grafts or bone grafts alone.
SPINAL STENOSIS - Reduction in the diameter of the spinal canal due to new bone formation. May result in pressure on the spinal cord or nerve roots.
SPINE - The flexible bone column extending from the base of the skull to the tailbone. It is made up of 33 bones, known as vertebrae. The first 24 vertebrae are separated by discs known as intervertebral discs and bound together by ligaments and muscles. Five vertebrae are fused together to form the sacrum and four vertebrae are fused together to form the coccyx. The spine is also referred to as the vertebral column, spinal column, or backbone.
SPINOUS PROCESS - The portion of the vertebrae that protrudes posteriorly from the spinal column. The spinous processes create the "bumps" felt on the midline of thre back.
SPONDYLITIS - Inflammation of vertebrae.
SPONDYLOLISTHESIS - A defect in the construct of bone between the supeior and inferior facets with varying degrees of displacement so the vertebra with the defect and the spine above that vertebra are displaced forward in relationship to the vertebrae below. It is usually due to a developmental defect or the result of a fracture.
SPONDYLOLYSIS - Displacement of one vertebrae over another with fracture of a posterior portion of the vertebra. A defect in the neural arch between the superior and inferior facets of vertebrae without separation at the defect, and therefore, no displacement of the vertebrae. It may be unilateral or bilateral and is usually due to a developmental defect but may be secondary to a fracture.
STAINLESS STEEL - Iron-based metal containing chromium that is highly resistant to stain, rust, and corrosion. Certain grades of stainless steel are commonly used to make surgical implants and instruments.
STENOSIS - Narrowing.
STEREOTACTIC - Originated from the Greek words stereo meaning three dimensional and tactos meaning touched and relating to stereotaxy.
STEREOTACTIC RADIOSURGERY - The precise delivery of radiation to a preselected stereotactically localized target.
STEREOTAXY - A precise method of destroying deep-seated brain structures located by use of three dimension coordinates.
STERILE - Free from living organisms.
STERILIZATION - The method used to render a material free from living organisms. Usual methods include steam under pressure, gas, and ionizing radiation.
STRABISMUS - Deviation of eye movement which prevents the two eyes from moving in a parallel fashion.
SUBARACHNOID HEMORRHAGE - Blood in or bleeding into the space under the arachnoid membrane. Most commonly from trauma or from rupture of an aneurysm.
SUBDURAL HEMATOMA - A collection of blood (clot) trapped under the dura matter, the outermost membrane surrounding the brain and spinal cord.
SUPERIOR - Situated above or directed upward toward the head of an individual.
SYRINGOMYELIA - A fluid filled cavity in the spinal cord.
T
TENDON - The fibrous band of tissue that connects muscle to bone. It is mainly composed of collagen.
TENTORIUM CEREBELLI - The process of the dura matter between the cerebrum and cerebellum supporting the occipital lobes.
TERATOMA - Tumor or growth made up of several different types of tissue, such as fat, bone, muscle, and skin.
THALAMUS - Brain cells which lie in the upper part of the brain stem.
THIRD PARTY PAYOR - The source of reimbursement or payment of charges for medical services when the patient does not make direct payment, i.e., payments made by insurance companies, government agencies, or employers. The patient and the doctor represent the two other parties in third party pay arrangements.
THORACIC - The chest level region of the spine that is located between the cervical and lumbar vertebrae. It consists of 12 vertebrae which serve as attachment points for ribs.
THROMBUS - A blood clot attached to the wall of an artery.
TIC DOULOUREUX - See trigeminal neuralgia below.
TITANIUM - A metallic element used to make surgical implants.
TOXICOLOGY - The study of the toxic or harmful effects of substances on the body.
TRACTOTOMY - Surgical section of a fiber tract of the central nervous system.
TRANSPLANT - The implantation of bone tissue, as in grafting, from one part of the body to another. Transplant also refers to the transfer of an organ, such as a kidney or heart, from one individual to another.
TRANSSPHENOIDAL APPROACH - Operative method of reaching the pituitary gland or skull base traversing the nose and sinuses.
TRIGEMINAL NEURALGIA - Paroxysmal pain in the face. Pain may be so severe that it causes an involuntary grimace or "tic."
TUMOR - Any swelling or tumefaction.
U
ULTRASOUND - The use of high-frequency sound to create images of internal body structures.