Classification & Terminology
The damage from TBI can be focal, confined to one area of the brain, or diffuse, involving more than one area of the brain. Diffuse trauma to the brain is frequently associated with concussion (a shaking of the brain in response to sudden motion of the head), diffuse axonal injury, or coma. Localized injuries may be associated with neurobehavioral manifestations, hemiparesis or other focal neurologic deficits.
Types of focal brain injury include bruising of brain tissue called a contusion and intracranial hemorrhage or hematoma, heavy bleeding in the skull. Hemorrhage, due to rupture of a blood vessel in the head, can be extra-axial, meaning it occurs within the skull but outside of the brain, or intra-axial, occurring within the brain. Extra-axial hemorrhages can be further divided into subdural hematoma, epidural hematoma, and subarachnoid hemorrhage. An epidural hematoma involves bleeding into the area between the skull and the dura. With a subdural hematoma, bleeding is confined to the area between the dura and the arachnoid membrane. Bleeding within the brain itself is called intracerebral hematoma. Intra-axial bleeds are further divided into intraparenchymal hemorrhage which occurs within the brain tissue itself and intraventricular hemorrhage which occurs in the ventricular system.
TBI can result from a closed head injury or a penetrating head injury. A closed injury occurs when the head suddenly and violently hits an object but the object does not break through the skull. A penetrating injury occurs when an object pierces the skull and enters brain tissue.
As the first line of defense, the skull is particularly vulnerable to injury. Skull fractures occur when the bone of the skull cracks or breaks. A depressed skull fracture occurs when pieces of the broken skull press into the tissue of the brain. A penetrating skull fracture occurs when something pierces the skull, such as a bullet, leaving a distinct and localized injury to brain tissue. Skull fractures can cause cerebral contusion.
Another insult to the brain that can cause injury is anoxia. Anoxia is a condition in which there is an absence of oxygen supply to an organ’s tissues, even if there is adequate blood flow to the tissue. Hypoxia refers to a decrease in oxygen supply rather than a complete absence of oxygen, and ischemia is inadequate blood supply, as is seen in cases in which the brain swells. In any of these cases, without adequate oxygen, a biochemical cascade called the ischemic cascade is unleashed, and the cells of the brain can die within several minutes. This type of injury is often seen in near-drowning victims, in heart attack patients, or in people who suffer significant blood loss from other injuries that decrease blood flow to the brain.
Other terms you may encounter include:
ALIF – Anterior Lumbar Interbody Fusion – is the placement of bone or cages between vertebrae from an anterior approach.
Annulus – The outer portion of a disc in the spinal column, the annulus provides structure and strength to a disc and is comprised of a complex series of interwoven layers of fibrous tissues, which hold it’s nucleus in place.
Anterior – Refers to the frontal or ventral surface of the body.
Arthroscopic Lumbar Discectomy – PLD using an endoscope for visualization.
Autograft – This refers to bone taken from the patient, usually the hip, to be used as graft.
Bone Graft – An option for fusing the spine. This requires either moving bone from one part of the body (autograft) or using bone from an outside source (allograft).
Cat Scan – Computerized x-ray system which provides cross-sectional images of the spine or other parts of the body. Sometimes is done following a myelogram or discogram.
Cervical – Pertains to the neck.
Conservative Therapy – Method of relieving pain with bed rest, analgesics and chiropractic and physical therapy.
Degenerative Disc Disease – Deterioration in disc structure and function, which commonly causes pain and loss of function.
Diagnostic – Test or process used to determine the source of a problem, i.e., a diagnosis.
Disc – Discs serve as shock absorbers between the vertebrae of the spinal column. The center of the disc is known as the nucleus and the outer ring of the disc is called the annulus.
Discectomy – The procedure where a disc is removed surgicaly.
Discogram – Provocative discography is the instillation of sterile saline (not dye) into the disc to try and reproduce the patient’s pain.
Dorsal – Refers to a position toward the posterior or back side of the body.
Fusion – Growth of bone where bone does not normally grow, as in replacing a disc with a bone graft. The bone graft is normally taken from the patient or a donor.
Herniated Disc – AKA a slipped disc, is a condition in which nucleus tissue is moved from the center of a disc into the spinal canal. Herniated discs cause great pain in the low back and leg or the neck and arm and they create pressure against one or more of the spinal nerves. Other names for herniated discs are prolapsed discs or ruptured discs.
Interbody Fusion – Placing of a graft or cages between vertebral bodies.
Kyphoplasty – A surgical procedure designed to stop the pain caused by the bone fracture, stabilize the bone, and to restore the lost vertebral body height due to the compression fracture.
Laminectomy – Surgery technique in which part of the back of the vertebra is removed in order to reach to the nerves and discs. This may or may not require the disc be removed as part of the procedure.
Ligaments – This is bands of fibrous tissue that connect bones or cartilages that support and strengthen the bone joints. Ligaments surround the spine on all sides.
Lumbar – This refers to the lower back.
Microdiscectomy – Surgical technique for removal of a disc via a small opening using a microscope.
Morbidity – Refers to postoperative pain and complications from to surgery.
MRI Scan – Computerized magnetic imaging system that provides cross-sectional images of the spine or other body parts.
Myelogram – Diagnostic procedure in which an iodine is injected as a dye into the spinal canal and shows up on x-rays that are taken.
Nucleus – The center part of a disc and is made of a soft, rubber-like material that takes the shock of movement such as standing, walking, running, etc.
Pedicle Fixation – Invlolves placing bone screws into the spine from a posterior approach through what is known as the pedicle. Screws are then used with a rod or plate to keep the spine stable following bone grafting.
Percutaneous Cervical Discectomy – An outpatient procedure that uses minimally-invasive suction to remove herniated cervical discs.
Percutaneous Lumbar Discectomy – PLD using an endoscope for visualization.
PLIF – Stand for Posterior Lumbar Interbody Fusion, which is the placement of bone or cages between vertebrae from a posterior approach.
PLITF – Stands for Posterior Lateral Inter-Transverse Process Fusion, which involves the placement of bone graft on and between transverse process of vertebrae to promote bone fusion.
Porous – Surface area amount which allows for bone growth from the implant.
Posterior – This term refers to the back or dorsal surface of the body.
Prolapsed Disc – AKA a slipped disc, is a condition in which nucleus tissue is moved from the center of a disc into the spinal canal. Herniated discs cause great pain in the low back and leg or the neck and arm and they create pressure against one or more of the spinal nerves. Other names for herniated discs or ruptured discs.
Ruptured Disc – See above
Sacrum – This is the lower portion of the spinal column.
Slipped Disc – See Ruptured Disc.
Spinal Cord – This is the primary nervous system, that runs from base of the skull to the lower back via the spinal canal. Problems or impingement of bony or soft tissues on cord or nerve roots is primary reason for spine surgery.
Spinal Fusion – Surgical treatment for back pain in which the disc between two adjacent vertebrae is removed. Then two vertebrae are fused using bone graft and instrumentation methods.
Spine – This is the structure composed of vertebrae, discs, and ligaments. It contains 26 vertebrae in five separate regions. There are 7 cervical, 12 thoracic, 5 lumbar, 1 sacral, and 1 coccygeal vertebrae. The primary function of the spine are body support and spinal cord protection.
Spinal Column – Longitudinal skeletal axis of the human body that is composed of 26 distinct bones which are called vertebrae.
Therapeutic – A procedure which is related to the treatment of disease in the human body.
Thoracic Spine – The twelve vertebrae in mid-torso that are attached to the rib cage.
Thorax – The portion of the chest composed of the spine, ribs and, breast bone.
Titanium Alloy – This is a very bio-compatible material with great fatigue strength and good imaging characteristics.
Vertebra – This a bone that is used as a building block for the spinal column.
Vertebral Column – The longitudinal skeletal axis of the body that is composed of 26 distinct bones which are called vertebrae.