Neuroglossary
Terms used in brain injury, spinalﾠcord injury and other neurotrauma treatment and rehabilitationﾠ
decussation - Branching or splitting into two divergent pathways, as at the optic chiasma.
degenerated disc disease (DDD) - Mechanical breakdown of the integrity of a disc, which produces symptoms initially because of mechanical instability and later productive of root or cord compression owing to the development of osteophyte outgrowths.
delirium - A state of confusion often associated with hallucinations and hyperactivity, in which the patient is inaccessible to normal contact.
dementia - A general loss of intellectual abilities of sufficient severity to interfere with social or occupational functioning. Emotions, personality, and behavior are invariably affected. Caused by an organic brain lesion.
dendrite - A fine branching process of the nerve cell which conducts a nerve impulse from the cell body to the structure(s) supplied by the nerve, or toward the cell
body.
denervation - Resection or removal of the nerves to an organ or part.
dens axis - Tooth of the axis (C2); the tooth-like process that projects from the upper surface of the body of the axis, as a pivot, a peglike protrusion, to articulate with the atlas (C1), also called the odontoid bone, etcetera.
depression (dysthymia) - An abnormal lowering of mood of psychologic or physiologic origin which is more prolonged than mourning and is time-limited and related to a specific loss.
dermatomes - The characteristic distribution of sensory innervation on the skin of the body and the limbs.
development - (In general) Refers to the process wherein an organism changes over maturation, according to specifically designed programs encoded in its individual genetic code. In normal development, this code is presumed to reflect the typical development code of the species, with some room for idiosyncratic variation within an anticipated range. In general, development in each of the various areas identified proceeds at a rate consistent with, and supportive of, the development of other areas, and appears as an integrated, interactive process.
diagnostic overshadowing (Concept) - Once a diagnosis is made of a major condition (such as TBI) there is a tendancy to attribute all other problems to that diagnosis, thereby leaving other co-existing conditions undiagnosed.
dermatome - The area of skin supplied by afferent nerve fibers by a single posterior spinal root; used in locating injuries to dorsal roots of the spinal cord. Called also dermatomic area. Also refers to an instrument for cutting thin skin slices for skin grafts.
diarthrodial joints - Joints between individual segments of the spine such as apophyseal, zygapophyseal, or facet joints, which provide for both mobility and stability and, by their arrangement, help to equitably distribute load from the top of the spine to the bottom. These articulations limit the mobility between two vertebrae to a predetermined degree and direction.
diarthrosis - A joint, classified as to the degree of motion, as a freely movable joint.
diencephalon - So called "midbrain" or interbrain connected to the cerebral hemisphere; contains pituitary gland.
differentiation - The process by which cells develop into specialized tissues and organs.
diffuse axonal injury (DAI) - Widespread distribution of and damage to white matter of the brain due to rotational shearing forces coincident with head trauma.
dilatation - The condition of being dilated or stretched beyond the normal dimensions.
digital subtraction angiography (DSA) - Non-invasive exploratory technique that uses a digital computer to produce three-dimensional pictures of blood vessels.
diplopia - Double vision. A muscle imbalance between the eyes causes stimulus to be received in different parts of the retina.
disability - Any restriction or lack (resulting from an impairment) of ability to perform an activity in a manner or within the range considered normal for a human being.
disc degeneration - A wearing down of the disc that generally causes mechanical instability and osteophytes.
disc herniation - General term that describes either disc prolapse, protrusion, or extrusion. (See herniated intervertebral disc.)
disc(k)ogram - Roentgenogram of an intervertebral disc.
dislocation - Displacement of bone in a joint so that two articulating surfaces become separated; also called luxation.
displaced - When either a herniated disc or a degenerative bony overgrowth such as an osteophyte affects the nearby nerves; indicates a change in the usual position of a nerve root or thecal sac.
displacement - Removal from the normal position or place.
distal - Relative directional term indicating remote, farther from any point of reference, away from or farther from the trunk of the body or the attached end of a limb. The wrist is distal to the forearm. Opposed to proximal.
distraction - Distraction occurs when, without rupture of their supporting ligaments or without displacement, the joint surfaces are separated, or when there is too much space between fracture fragments because of interfering tissue, etc. Also refers to the surgical separation, after a bone is transversely divided, of the two parts of a bone.
distraction test - Test to determine if the patient has a disc herniation. The doctor pulls upward on the patientﾒs head, holding the chin and the back of the skull for thirty to sixty seconds. This should relieve pain if the patient has a disc herniation. The location of the relief will help in the diagnosis.
distractive extension lesion - An injury that is seen in an uppercut to the jaw or in a person who falls and hits their chin on the edge of a bathtub.
dizziness - A subjective and imprecise term which could refer to vertigo or a variety of disturbing conditions with a psychological basis.
dolor - The pain aspect of the inflammatory phase.
dorsal - Relative directional term that directs to the back or to any dorsum. It means more toward the back surface than another point of reference. In the hand or foot it refers to the upper surface and is the same as posterior. It is the opposite of ventral.
dorsiflexion - Upward flexion of the foot at the ankle joint.
dorsum - The back; an anatomical structureﾒs posterior or back vantage point.
double herniation - Rarely, there will be bilaterial disc herniations at the same intervertebral disc level. Usually, in this condition, the central disc appears normal. However, on both sides, paracentral or foraminal/extraforaminal herniations are found. Since this condition is not often encountered, the lesion is usually simply described in detail.
DMS III-R - The Diagnostic and Statistical Manual of the American Psychiatric Association, Third Edition, Revised; the standard guide to the classification of mental disorders. The manual is generally accepted as providing definitive definitions and descriptive (phenomenologic, not based on a particular theory) criteria for a variety of mental disorders.
DSM-IV - The Diagnostic and Statistical Manual of the American Psychiatric Association Fourth Edition; the standard guide to the classification of mental disorders. Specifically addresses the use of the term mental although acknowledging that there is much physical in mental disorders and much mental in physical disorders (Introduction, xxi). The manual is generally accepted as providing definitive definitions and descriptive (phenomenologic, not based on a particular theory) criteria for a variety of mental disorders.
dura mater - The fibrous tough outer sheath surrounding the brain and spinal cord.
dural sac - As the dura mater extends beyond the lower end of the spinal cord, it is called the dural sac. It is also made up of the arachnoid mater.
dynamic - Pertaining to or manifesting force.
dynamics - That phase of mechanics that deals with the motion of material bodies taking place under different, specific conditions.
dynamic spatial reconstructor (DSR) - Scanning device used to see the blood flow through the brain. Computer generated, it produces three-dimensional pictures of the active brain.
dysarthria - Defective articulation due to disorders of the vocal apparatus.
dysesthesia - Impairment of any sense, especially that of touch.
dysphagia - Difficulty in swallowing.
dysphonia - Any impairment of voice or a difficulty in speaking.
