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Reflex Sympathetic Dystrophy
Glossary of Terms

A    B    C    D    E    F    G    H    I    J    K    L    M    N    O    P    Q    R    S    T    U    V    W    X    Y    Z

This is by no means a complete medical glossary. It is, rather, an attempt to define the terms used when talking about RSD. This glossary is put together based on years of reading books and medical journal articles on RSD and Lupus and through talking with numerous medical professionals. I offer it as is, with no warrantees or promises. I think that you will find it useful. If you wish to add some terms or have any comments about my definitions, please send us mail. Thanks.

A

Agnogenic
idiopathic; of unknown origin. a = not, gno = knowledge, genesis = origin
Allodynia
Pain produced by stimuli that normally does not cause pain. This can be moderate heat or cold or light touch. With RSD, even something as light as the weight of a bed sheet touching the skin can cause pain.
Analgesia
The absence of pain in response to stimuli which would ordinarily be painful.
Ankylosis
The stiffening or fixation of a joint.
Arteritis
Inflamation involving an artery
Arteriorsclerosis
Hardening of the arteries; types essentially recognized are: artherosclerosis, Monckeberg's a., hypertensive a., and arteriosclerosis..
Arthropathy
Disease affecting a joint.
Atrophy
A wasting of tissues, as from death and reabsorption of cells, diminished cellular proliferation, pressure, ischerma, malnutrition, decreased function or hormonal changes.
Autonomic changes
  1. Alterations in blood flow, hyperhidrosis, edema.
  2. Autonomic - functionally independent; not under voluntary control.
  3. Relating to the autonomic nervous system.
Autonomic Nervous System
Part of the peripheral nervous system, ANS controls the body's internal organs and is composed of the sympathetic nervous system and the parasympathetic nervous system. The ANS works in conjunction with the endocrine system (hormones). It controls blood circulation, gastrointestinal activity, body temperature and innervates smooth muscle, cardiac muscle and glands. The part of the vertebrate nervous system that regulates involuntary action, as of the intestines, heart, and glands, and that is divided into the sympathetic nervous system and the parasympathetic nervous system.

B

Bone Scanning
The use of a radioactive compound to detect bone lesions, including RSD and arthritis. Radioactive compound accumulates in areas of increased bone growth or turnover. This sensitive test shows subtle abnormalities that may not show up in X-rays, CT scans or MRIs.
Brawny Edema
Thickening and dusky discoloration of edematous tissue. This is a common symptom of RSD. See also edema.

C

Causalgia
Persistent severe burning sensation of the skin, usually following direct or indirect (vascular) injury of sensory fibers of a peripheral nerve, accompanied by cutaneous changes (temperature and sweating).
Cutaneous
Relating to the skin. See also subcutaneous.

D

Dysesthesia
Unpleasant, abnormal sensation.
Dystrophic
Defective nutrition. With RSD, dystrophy means that if left untreated, the RSD symptoms uniformly result in trophic changes due to the persistent sympathetic stimulation.

E

Edema
  1. Fluid build up in cell tissues that causes noticeable swelling.
  2. An accumulation of an excessive amount of watery fluid in the cell tissues or serous cavities.
    See also: brawy edema.
Electromyography
The examination of skeletal muscle by the use of needle electrodes. Abnormal muscle activity, both at rest and with movement, indicates instability of muscle membranes, denervation, muscle disease, or alterations in the motor unit. Research indicates that patients with RSD do not show abnormal EMG results.
Embolus
Emboli = plural.
A plug, composed of a detached clot or vegetation, mass of bacteria, or other foreign body, occluding(blocking) a blood vessel (embolism).
EMG
see Electromyography.

F

Fascia
A sheet of fibrous tissue that envelops the body beneath the skin. It also enclosed muscles and muscle group, and separates their several layers or groups.
Fibrosis
A thickening and scarring of the connective tissue.
Fight or Flight Reaction
A set of physiological changes, such as increases in heart rate, arterial blood pressure, and blood glucose, initiated by the sympathetic nervous system to mobilize body systems in response to stress.

G

Ganglion
A group of nerve cells forming a nerve center, especially one located outside the brain or spinal cord.
plural: Ganglia
Glomus Tumor
definition to come.

H

Herpes Zoster
Acute viral infection, characterized by inflammation of the sensory ganglia of certain spinal or cranial nerves and the eruption of vesicles along the affected nerve path. It usually strikes only on one side of the body and is often accompanied by severe neuralgia. Herpes Zoster a virus left in the body by chicken pox and activated by stress or by age. It is also known as shingles.
Hyperalgesia
Increased response to normally painful stimulus; lowered pain threshold.
Hypesthesia
Decreased sensitivity to sensory stimuli. Decreased sensitivity to touch or other stimulus.
Hyperesthesia
  1. Abnormal acuteness of sensitivity to sensory stimuli, including touch and light pressure.
  2. Acute sensitivity to touch or other sensory stimulus.
  3. Increased sensitivity to stimulation.
. Sometimes spelled hyperasthesia.
Hyperhidrosis
Excessive or profuse sweating.
Syn.: hyperhydrosis, polyhidrosis.
Hyperhydrosis
Excessive or profuse sweating.
Syn.: hyperhidrosis, polyhidrosis.
Hyperpathia
Delayed overreaction and aftersensation of a stimulus, especially to something recurrent. Hyperpathia is quite common in RSD, particularly in stage I.
Hypoalgesia
Diminished pain response to normally painful stimulus.
Hypoesthesia
Decreased sensitivity to stimulation.

I

Idiopathic
  1. denoting a disease of unknown cause.
  2. denoting a primary disease
    syn: agnogenic
Infarction
  1. An insufficient supply of arterial or venous blood causes tissue to die.
  2. Sudden insufficiency of arterial or venous blood supply due to emboli, thrombi, vascular torsion or pressure that produces a macroscopic area of necrosis.
Ischerma
Local anemia due to mechanical obstruction (mainly arterial narrowing) of the blood supply.

J

Joint stiffness
definition to come.

L

Lumen
The space in the interior of a tubular structure, such as an artery or the intestine.

M

Macroscopic
Visable to the naked eye.
ant.: microscopic.
Mechanoreceptors
Specialized sensory organ that handles mechanical stimuli such as pressure, tension or displacement.

The most diverse group of sensory receptors, mechanoreceptors are found in muscles, skin, joints, and visceral organs and are sensitive to mechanical deformation of the tissue and cell membranes. The deformation can arise in various ways, including indentation, stretch and hair movement. The skin receptors include the largest variety of mechanoreceptors. Many of the sensory nerve endings encapsulated in a fibrous (connective tissue) covering are believed to be mechanoreceptors.

Myocardial Infarction
Also known as an MI or a cardiac infarction.
Infarction of the heart muscle, usually as a result of the occlusion (blockage) of a coronary artery. An infarction is when an insufficient supply of arterial or venous blood causes tissue to die.
Myocardium
The middle layer of the heart, which is made of cardiac muscle.
Myoclonus
Spasm or twitching of a muscle or group of muscles, characterized by alternate contraction and relaxation of muscle occurring in rapid succession.
Myofascial
Of or relating to the fascia surrounding and separating muscle tissue.

N

Necrosis
Pathologic death of one or more cells, or of a portion of tissue or organ, resulting from irreversible damage.
The most frequent visible alterations are nuclear: pyknosis, karyolysis or karyorrhexis.
Neuralgia
Pain along a nerve path; Severe throbbing or stabbing pain along a nerve path.
Neuritis
Inflammation of a nerve or nerves.
Neurogenic Pain
Pain caused by a primary lesion or dysfunction in the peripheral nervous system or central nervous system.
Neuropathy
A disturbance of the function of a nerve or a pathological change in a nerve.
Nociceptor
A sensory receptor that deals with pain. Nociceptors are the free nerve endings that react when certain internal nociceptive substances, such as serotonin, substance-P, histamine, and kinin peptides (bradykinin, etc.) are released by injured tissue.
Nodosa
Having nodes or knotlike swellings.
Norepinephrine
norepinephrine (nôr´èp-e-nèf¹rîn) or noradrenaline, the neurotransmitter that mediates chemical communication in the sympathetic nervous system. Like other neurotransmitters, it is released at synaptic nerve endings to transmit the signal from a nerve cell to other cells. It is almost identical in structure to epinephrine. The sympathetic nervous system functions in response to short-term stress (the fight or flight response); hence norepinephrine and epinephrine increase the heart rate as well as blood pressure, increase the rate of glycogen conversion for energy, and relax bronchial smooth muscle to assist breathing. A substance, C8H11NO3, both a hormone and neurotransmitter, secreted by the adrenal medulla and the nerve endings of the sympathetic nervous system to cause vasoconstriction and increases in heart rate, blood pressure, and the sugar level of the blood. Also called noradrenalin.
Noxious Stimulus
Something damaging to the normal tissues. Stimulus strong enough to cause pain are usually noxious, releasing certain chemicals that act on the nociceptors causing pain signals to be transmitted.

O

Osteoid
Painful benign neoplasm, usually originating in one of the bones of the lower extremities, characterized by a nidus that consists of osteoid material, vascularized osteogenic stroma and poorly formed bone, around the nidus, there is a relatively large zone of reactive thickening of the cortex.
Osteopenia
  1. Decreased calcificatin or decreased density of bone.
  2. Reduced bone mass due to inadequate osteoid synthesis.

P

Pain Threshold
The smallest amount of pain which a person can recognize. Pain thresholds differ from person to person. Fortunately most humans have a fairly high pain threshold and it takes quite a lot of pain to activate these signals. People with RSD generally have a much lower pain threshold than normal.
Paresthesia
An abnormal sensation.
Parasympathetic Nervous System
From ms bookshelf parasympathetic nervous system noun The part of the autonomic nervous system originating in the brain stem and the lower part of the spinal cord that, in general, inhibits or opposes the physiological effects of the sympathetic nervous system, as in tending to stimulate digestive secretions, slow the heart, constrict the pupils, and dilate blood vessels.
Periarticular
Surrounding a joint.
Periarteritis
Inflamation of the parts surrounding a joint.
Peripheral
  1. Near or on the edge.
  2. Situated nearer the periphery (edge) of an organ or body part, such as peripheral nerve.
Peripheral Nervous System
The part of the vertebrate nervous system constituting the nerves outside the central nervous system and including the cranial nerves, the spinal nerves, and the sympathetic and parasympathetic nervous systems.

R

Receptor
A specialized cell or group of nerve endings that responds to sensory stimuli. For example, mechanoreceptors, caloreceptor, which detects warmth, thermoreceptor, which responds to heat and cold, and nociceptor, which responds to pain..
Reflex Sympathetic Dystrophy
Very briefly, RSD is a chronic pain syndrome occurring in the limbs. The pain is usually burning in nature, which is why it is often referred to as causalgia. RSD happens after an injury, after surgery or as the result of a tumor. Associated with RSD are sensory, motor, autonomic and trophic changes. The symptoms are variable and many terms are used interchangeably with RSD. For more about RSD, you will want to go to the RSD Network Home Page and/or get a copy of the RSDnet FAQ. The term Complex Regional Pain Syndrome I had been proposed by the IASP (International Association for the Study of Pain) as a replacement for the term RSD, but CRPS I has not achieved wide use.
Reflex Sympathetic Dystrophy Network
A great place on the Internet to find out more about RSD and the home of this glossary.

S

Sensory Receptor
definition to come.
SMP
see Sympathetically Maintained Pain
Subcutaneous
Beneath the skin.
Sudeck's Atrophy
Acute atrophy of a bone, commonly one of the carpal or tarsal bones, following a slight injury such as a sprain.
Sudomotor Disturbances
Sudor, the act of sweating; sweat itself.
Denoting the nerves that stimuatle the sweat glands to activity.
Sympathectomy
Surgical or chemical removal of part of the sympathetic nervous system. This has been used in the past, with mixed results, for treatment of RSD. See the document Treatment of RSD for more information on sympathectomies.
Sympathetic Nervous System
The part of the autonomic nervous system originating in the thoracic and lumbar regions of the spinal cord that in general inhibits or opposes the physiological effects of the parasympathetic nervous system, as in tending to reduce digestive secretions, speeding up the heart, and contracting blood vessels.
Sympathetically Maintained Pain
Terms applied to any pain that is sustained, at least in part, by sympathetic afferent activity.

T

TENS
see Transcutaneous Electrical Nerve Stimulation.
Thermography
A noninvasive method for measuring the thermal patterns (heat and cold distribution) in a body. Normally the body has a symmetrical heat pattern, but certain pain syndromes, such as neuropathic disorders, have a special thermal pattern and use of thermography can help in the diagnosis. Sympathetic dysfunction, such as in RSD, is easily diagnosed by this technique.
Thrombus
Thrombi = plural.
A clot in the cardiovascular systems formed during life from constituents of blood; it may be either acclussive or attached to the vessel or heart wall without obstructing the lumen.
Thrombophlebitis
Venous inflammation with thrombus formation.
Torsion
  1. Twisting or rotation of a part upon its long axis.
  2. twisting of the cut end of an artery to arrest hemorrhage.
  3. rotation of the eye around its anteroposterior axis.
Transcutaneous Electrical Nerve Stimulation
This is a small battery-operated device, about the size and shape of a pager, that consists of a set of electrodes that are placed on the skin around the site of the pain and through which a low-voltage electrical stimulus is passed. The low-voltage electrical charge acts on nerve fibers to interrupt pain signals. It is a form of external peripheral nerve stimulation and may reduce pain by acting as a counterirritant, stimulating sensory nerve fibers, closing the gate on the pain signals and acting as a distractant. TENS has been effective in reducing pain and improving physical function. It is often used in conjunction with drug therapy.
  Nerve stimulation may decrease muscle spasm, increase relaxation, increase the ability to exercise and perform range of motion movements, increase blood flow and metabolism, and decrease pain. The medical literature suggests a trial (especially for patients who do not respond promptly to blocks) even though only a few patients attain long-term analgesia.
  TENS is commonly used to treat neuropathic pain, such as a RSD and causalgia, low-back pain, arthritis, phantom limb pain, cancer pain, headache and post-op pain.
Trophic Changes
definition to come.
Tremor
An involuntary trembling or shaking movement.

V

Vasomotor disturbances
definition to come.
Vascular
Relating to or containing blood vessels.

Make sure to check out the main pages of the
Reflex Sympathetic Dystrophy Network web site.

This page was last updated on May 20, 1997.

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