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C

C# – The letter C followed by a number identifies a specific vertebra in the cervical spine. For example, C3 is the 3rd vertebra in the cervical spine.

CAROTID ARTERY – The large artery on either side of the neck that supplies most of the cerebral hemisphere.

CAROTID DUPLEX (CAROTID ULTRASOUND):  A test in which ultrasound is used to help detect plaque, blood clots, or other problems with blood flow in the carotid arteries (the main arteries in the neck that supply blood to the brain).  A water-soluble gel is placed on the patient’s skin where a transducer (a hand-held device that directs high frequency sound waves to the arteries being tested) is placed.  The gel helps transmit the sound to the skin surface.  The ultrasound is turned on and images of the carotid arteries and pulse wave form are obtained.  There are no known risks and this test is noninvasive and painless.

CATHETER – A small tube inserted in a body cavity duct or vessel to allow drainage or injection of fluids or access by surgical instruments.

CAUDA EQUINA – The bundle of spinal nerve roots arising from the end of the spinal cord and filling the lower part of the spinal canal.

CAUTERIZE – The act of cutting and sealing or clipping something within the body.

CENTRAL NERVOUS SYSTEM (CNS) – One of two major divisions of the body’s nervous system, the CNS is a collective term for the brain and spinal cord, and their corresponding nerves and cells. It is often called the “control network” and is responsible for regulating bodily functions, processing sensations and sending signals to different parts of the brain.

CEREBELLUM – Means “small brain” in Latin, and refers to the portion of the brain in the back of the head between the cerebrum and the brain stem. It is responsible for balance and equilibrium, muscle control, and coordination of voluntary movement. Damage to this part of the brain can interfere with a person’s ability to walk, talk and eat, and to perform other self-care tasks.

CEREBRAL ANEURYSM – See Aneurysm.

CEREBRAL ANGIOGRAPHY (VERTEBRAL ANGIOGRAM, CAROTID ANGIOGRAM) – Arteries are not normally visible in an X-ray, so contrast dye is utilized.  The patient is given a local anesthetic, the artery is punctured, usually in the leg, and a needle inserted into the artery.  A catheter, or a long, narrow, flexible tube, is inserted into the artery.  It is then threaded through the main arteries of the abdomen and chest until it is properly placed in the arteries of the neck (carotid arteries).  This procedure is monitored by a fluoroscope (a special X-ray that projects the images on a TV monitor).  The contrast dye is then injected into the neck area through the catheter, and X-rays are taken.

CEREBRAL EDEMA – A swelling of the brain due to increased fluids in or around the brain tissue. Edema occurs most often because of head trauma.

CEREBRAL HEMORRHAGE –  Bleeding within the brain resulting from a ruptured blood vessel, aneurysm, or head injury.  A cerebral aneurysm may also leak and spill blood into the surrounding tissue.  Some cerebral aneurysms, especially small ones, do not bleed or cause other problems.  Most cerebral aneurysms are located along a loop of arteries at the base of the skull called the Circle of Willis.

CEREBROSPINAL FLUID (CSF) – The fluid located inside the spine. A lumbar puncture or spinal tap will look for blood in the fluid, as this is a sign that there may be a hemorrhage.

CEREBROVASCULAR – Of or relating to the brain and the blood vessels that supply it.

CEREBRUM – The largest portion of the brain, divided into two (right and left) hemispheres that each contain four lobes: frontal, parietal, occipital, and temporal. Its functions include speech, memory, vision, personality and muscle control in certain parts of the body.

CERVICAL – Describing or related to the neck. Cervical vertebrae are the bones at the top of the spine, which are found in the neck. A cervical fracture is a break in the vertebrae in the neck.

CERVICAL FUSION –  Surgical procedure performed to eliminate movement over painful or unstable spinal segments of the seven vertebra of the cervical spine (neck region) that are separated from one another by intervertebral disks.  These discs allow the spine to move freely and act as shock absorbers.  Cervical fusion relieves the pressure on one or more nerve roots, or on the spinal cord, by stabilizing two or more vertebrae by fusing them together.  The fusion stops the vertebral motion that causes pain.

Through a small incision in the front of the neck, the neurosurgeon uses an operating microscope for increased magnification, and with microinstruments removes the affected intervertebral disk, this is called a decompression.  The disc is replaced with an interbody graft that will fuse the vertebrae together over time.  In most cases, the neurosurgeon may use a metal plate to provide support to the neck so the bones can fuse adequately.  A cervical fusion procedure takes between two and six hours, depending on the number of vertebrae involved, whether instrumentation is indicated, and other factors.

CIRCLE OF WILLIS – Refers to a circle of arteries at the base of the brain. This area is where the majority of cerebral aneurysms develop. It is named after Thomas Willis, an English physician from the 17th century.

CLINICAL DEPRESSION – A mental state, marked by symptoms of depression (feelings of low self esteem, guilt, self reproach, withdrawal from interpersonal contact, physical disturbances, pessimism, etc.) that last two weeks or more and are so severe that they interfere with daily living.

CLIP LIGATION – See Microvascular Clipping.

COCCYX – (Also called the tail bone) The small bone at the end of the spinal column, formed by the fusion of four rudimentary vertebrae.

COIL EMBOLIZATION – Since approved by the FDA in 1995, endovascular coils have become increasingly popular for their effectiveness for permanent obliteration of a brain aneurysm.  Guglielmi detachable coils, or GDSs, are soft wire spirals made out of platinum.  They are released into an aneurysm through a catheter that is inserted into an artery in the groin and advanced into the brain.  Once the coils are released into the aneurysm, the blood flow is slowed so a thrombosis (clot) is formed in the aneurysm, and a thrombosed aneurysm cannot rupture.  Endovascular coiling is also popular because it is less invasive than other surgical procedures.

COMPUTERIZED TOMOGRAPHY (CT, CAT SCAN) – A diagnostic imaging test in which X-rays are employed to generate cross sectional images of an area.  Bone, blood, and brain tissue have very different densities that can easily be distinguished on a CT scan, and it is a useful diagnostic test for hemorrhagic strokes.  CT angiography allows clinicians to see blood vessels of the head and neck and is increasingly being used instead of an invasive angiogram.

CONCUSSION – A disruption, usually temporary, of neurological function resulting from a blow or violent shaking.

CONGENITAL – A condition that is congenital is one that is present at birth.

CONTUSION (BRAIN) – A bruise; an area in which blood that has leaked out of vessels is mixed with brain tissue.

CORTEX – The external layer of gray matter covering the hemispheres of the cerebrum and cerebellum.

CRANIAL NERVES – The 12 sets of nerves that originate from the brain stem, retina and nose. These mediate the special senses as well as provide the motor and sensory innervations of the head and neck.

CRANIOTOMY – An open neurosurgical procedure that requires removal of a portion of the skull in order to gain access to the brain and other intracranial structures.

CRANIUM – The part of the skull that holds the brain.

CT SCAN (COMPUTER TOMOGRAPHY SCAN) – A diagnostic imaging procedure that uses a combination of x-rays and computer technology to produce cross-sectional images (often called slices), both horizontally and vertically, of the body. A CT scan shows detailed images of any part of the body, including the bones, muscles, fat, and organs. CT scans are more detailed than general x-rays.

CYBERKNIFE® – A new minimally invasive approach to stereotactic radiosurgery that uses a combination of robotics and image guidance to deliver concentrated beams of radiation to intracranial targets, many of which are inoperable. The CyberKnife system (manufactured by Accuray) uses a highly flexible robotic arm, allowing access to tumors in difficult-to-reach locations. CyberKnife is able to locate the position of the tumor without the use of an invasive stereotactic head frame, and compensates for patient movement during treatment, constantly ensuring accurate targeting with sub-millimeter precision. The result is that physicians know exactly where the tumor is in real time, and can use maximum radiation without fear of harming surrounding healthy tissues.

D

DEEP BRAIN STIMULATION (DBS) – A surgical reversible procedure used to treat patients with Parkinson’s disease or essential tremors, who do not respond effectively to medications. The therapy involves implanting a device (brain pacemaker) to deliver mild electrical stimulation to block the brain signals that cause tremors, rigidity or slow movement.

DEPRESSED SKULL FRACTURE – A break in the bones of the head in which some bone is pushed inward, possibly pushing on or cutting into the brain.

DEPRESSION – See Clinical Depression.

DIAGNOSTIC – Test or process used to determine the source of a problem.

DISC – The intervertebral disc is made of strong tissues which are between each vertebra, acting as shock absorbers for the spine.  It is round donut shape, with a tough outer layer (annulus) that surrounds a jellylike material (nucleus).  Thick ligaments attached to the vertebrae hold the disc material in place.

DISC DEGENERATION – The normal wear-and-tear process of the spine that occurs after multiple annular tears have developed, resulting in the inner portion of the disc drying out and losing ability to function as a shock absorber. This, in turn, causes the vertebrae to become closer together producing increased stresses on bones, joints and ligaments.

DISCECTOMY – A surgical procedure in which part of a herniated (ruptured) disc is removed.  The goal of the surgery is to make the herniated disc stop pressing on and irritating the nerves which cause pain and weakness.  These procedures may be done using a microscope or minimally invasive method.

DISCOGRAM – A safe X-ray examination of the intervertebral discs of the spine.  Liquid contrast agent (a special dye) is injected by placing a needle into the center of the disc space.  This makes the disc visible on a fluoroscope monitor and X-ray film.  Dicsograms are used to locate precisely which discs are damaged and causing back pain.  Test results help determine the exact cause pain and determine if surgery is warranted.

DISLOCATION – A dislocation occurs when extreme force is put on a ligament causing the two bone ends to separate.

DOME – The round balloon-like portion of an aneurysm. The smaller portion of the aneurysm is called the neck.

DOPAMINE – A neurotransmitter, or chemical that transmits signals between nerve cells. It is present in regions of the brain that regulate movement, emotion, motivation and feelings of pleasure. Lack of dopamine is the primary cause of Parkinson's symptoms.

DOPPLER ULTRASOUND – A water soluble gel is placed on a transducer (a handheld device that directs high-frequency sound waves to the artery or vein being tested) and the skin over the veins or arteries of the extremity being tested.  There is a swishing sound on the Doppler if the venous or arterial system is normal.  Both the superficial and deep venous or arterial systems are evaluated.  There are no known risks and this test is noninvasive and painless.

DURA MATER – A tough fibrous membrane, which covers the brain and spinal cord, but is separated from them by a small space.

DYSPHASIA – A speech problem characterized by trouble forming words.

DYSKINESIA – An impairment of the ability to perform voluntary movements.

DYSTONIA – A movement disorder characterized by sustained muscle contractions, usually producing twisting and repetitive movements or abnormal postures or positions.

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