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Glossary of Terms

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Adhesions: A fibrous band or structure by which parts abnormally adhere.
Aetiology: study of disease causes
Allodynia: ordinarily nonpainful stimuli evoke pain.
Anaesthesia: The loss of feeling or sensation
Analgesia: of insensitivity to pain, even though the subject is fully conscious.
Analgesia dolorosa (also analgesia algera or anaesthesia dolorosa): Spontaneous pain in a body area that lacks sensation.
Analgesic: an agent that brings about analgesia
Arachnoid: lies within the vertebral canal and surrounds the spinal cord and the vertebral portion of the subarachnoid space. It extends from the foramen magnum to the S-2 vertebral level. Since the spinal cord ends at the L-2 vertebral level, a wide separation occurs between the arachnoid and pia mater, the lumbar cistern, filled with cerebrospinal fluid in which the cauda equina is suspended.
Arachnoid cyst A fluid-filled cyst lined with arachnoid membrane, frequently situated near the lateral aspect of the fissure of Sylvius; usually congenital in origin. Synonym: leptomeningeal cyst.
Arnold Chiari malformation: Chiari I herniation of medulla and cerebellar tonsils, 4th ventricle in normal position, Chiari II herniation of medulla, tonsils, vermis, 4th ventricle at foramen magnum, myelomeningocele, aqueductal stenosis most likely to be hydrocephalus, Chiari III further herniation, 4th ventricle below foramen magnum, encephalocele or myelomeningocele associated with: agenesis of corpus callosum, syrinx
Arteriovenous malformation: A tangled collection of abnormal blood vessels where there is an abnormal communication between the arterial and venous systems, mostly congenital. Common sites include; skin, liver, brain, brainstem and spinal cord, where they may cause headaches, seizures or bleeding (subarachnoid haemorrhage). Synonym: haemangioma
Aseptic meningitis A meningeal reaction in the cerebrospinal fluid sometimes occurring in the absence of an infecting organism. It can be due to a virus, foreign substance, diagnostic or therapeutic procedure, or to a tumour
Asymptomatic: Without obvious symptoms of disease.
Atrophy: A wasting away, a diminution in the size of a cell, tissue, organ or part.
Autoimmune A condition in which an individual's immune system starts reacting against his or her own tissues, causing diseases such as lupus.
Autonomic nervous system not under conscious control, comprising two antagonistic components, the sympathetic and parasympathetic nervous systems.
Regulates key functions including the activity of the cardiac (heart) muscle, smooth muscles (e.g., of the gut), and glands. The autonomic nervous system has two divisions: 1. Sympathetic nervous system: accelerates the heart rate, constricts blood vessels, and raises blood pressure. 2. parasympathetic nervous system slows the heart rate, increases intestinal and gland activity, and relaxes sphincter muscles.
Baricity The weight of one substance compared to the weight of an equal volume of another substance at the same temperature.
Calcification: The process by which organic tissue becomes hardened by a deposit of calcium salts within its substance.
Calcify: To deposit or lay down calcium salts, as in the formation of bone.
Carpal tunnel syndrome disturbance of median nerve function in the wrist as the nerve passes through the carpal tunnel.
Cauda Equina:  A bundle of spinal nerve roots which arise from the termination of the spinal cord proper, it comprises the roots of all the spinal nerves below L1.
Cauda Equina Syndrome: A clinical syndrome characterised by dull pain in the lower back and upper buttock region, analgesia in the buttocks, genitalia (or thigh), accompanied by a disturbance of bowel and bladder function.
Central nervous system: brain, cranial nerves and spinal cord. It does not include muscles or peripheral nerves.
Acronym: CNS
Central nervous system depressants: A very loosely defined group of drugs that tend to reduce the activity of the central nervous system. The major groups included here are ethyl alcohol, anaesthetics, hypnotics and sedatives, narcotics, and tranquillising agents (antipsychotics and antianxiety agents).
Clinical syndrome: represents a typical constellation of physical (and laboratory) findings that may be seen as part of a primary disease process.
Clinical trial: Research study conducted with patients, usually to evaluate a new treatment or drug.
Cerebrospinal axis: The central nervous system; the brain and spinal cord.
Cerebrospinal fluid: A clear, colourless fluid that fills the ventricles of the brain and the central canal of the spinal cord.
Cerebral ventricles: fluid-filled spaces in the brain
Cervical: Pertaining to the neck or to the neck of any organ or structure.
Chemolysis: The dissolving of the nucleus pulposus of a displaced intervertebral disk, usually by the direct injection of a proteolytic enzyme, especially chymopapain, into the diseased disk. 
Chiari: see Arnold Chiari malformation
Collagen: The protein substance of the white fibres (collagenous fibres) of skin, tendon, bone, cartilage and all other connective tissue. Collagenous= pertaining to collagen, forming or producing collagen.
Commensal: living within the body, as part of the normal flora.
Connective tissue: less specialised tissue that is rich in extracellular matrix (collagen, proteoglycan etc.) and that surrounds other more highly ordered tissues and organs.
Contiguous: Adjacent or in actual contact.
Dermatome:  (adj. Dermatomal) the area of the skin supplied by a spinal nerve.
Diabetic neuropathy: Long standing or poorly controlled diabetes can cause permanent peripheral and autonomic nerve dysfunction known as diabetic neuropathy.
Diaphoresis: Perspiration, especially profuse perspiration. Synonym: sudoresis.
Discectomy: Excision, in part or whole, of an intervertebral disk. Synonym: discotomy.
Discitis: Inflammation of an intervertebral disk or disk space which may lead to disk erosion.
Discogram: an investigation imaging the intervertebral disc by injection of dye and X-ray.
Dura: dura mater.
Dural sac: = thecal sac; contains the three meningeal layers
Dural tear: a frequent, usually inconsequential, complication of lumbar laminectomy, occurring in perhaps as many as 1 in 20 lumbar stenosis decompression operations.  Only a very small number of these require intervention.  
Dysaesthesia: An unpleasant abnormal sensation, whether spontaneous or evoked.
Dystonia: Disordered tonicity of muscle.
Encapsulated: wholly confined to a specific area, surrounded by a capsule. Localised.
Encephalopathy: Any degenerative disease of the brain.
Endoneural: Having to do with a nerve.
Epidural : within the spinal canal, on or outside the dura mater; synonyms extradural and peridural.
Epidural fibrosis: scar tissue in the space outside the dural sac; synonyms: peridural; extradural
Failed Back Surgery Syndrome: synonym: Post laminectomy syndrome; recurrent back/leg pain after surgery.
Fascia: The flat layers of fibrous tissue that separate different layers of tissue.
Fibrin: The insoluble protein formed from fibrinogen by the proteolytic action of thrombin during normal clotting of blood;  forms the essential portion of the blood clot.
Fibrinolytic: causing the dissolution of fibrin by enzymatic action
Fibrosis: The formation of fibrous tissue, fibroid or fibrous degeneration the term usually refers to tissue laid down at a wound site well vascularised at first (granulation tissue) but later avascular and dominated by collagen rich extracellular matrix, forming a scar.
Foramen (pl. foramina): A small opening, perforation, or orifice; a fenestra.
Granuloma: Chronic inflammatory lesion characterised by large numbers of cells of various types (macrophages, lymphocytes, fibroblasts, giant cells), some degrading and some repairing the tissues.
Hemiparesis: weakness on one side of the body
Herniation: Bulging of tissue through an opening in a membrane, muscle or bone.
Hydrocephalus: dilatation of the cerebral ventricles, most often occurring secondarily to obstruction of the cerebrospinal fluid pathways and accompanied by an accumulation of cerebrospinal fluid within the skull, the fluid is usually under increased pressure, but occasionally may be normal or nearly so.
Hyperaesthesia: A neurologic symptom where there is an unusual increased or altered sensitivity to sensory stimuli.
Hyperbaric: Characterised by greater than normal pressure or weight, applied to gases under greater than atmospheric pressure, as hyperbaric oxygen or to a solution of greater specific gravity than another taken as a standard of reference.
Hyperthyroidism: excessive thyroid activity causing  increased metabolic rate, enlargement of the thyroid gland, rapid heart rate, high blood pressure and various secondary symptoms.
Hypothyroidism: A deficiency of thyroid activity.
Iatrogenic: Induced inadvertently by the medical treatment or procedures or activity of a physician. synonym: nosocomial
Idiopathic: unknown cause
Inflammation: A localised protective response elicited by injury or destruction of tissues, which serves to destroy, dilute or wall off (sequester) both the injurious agent and the injured tissue.
It is characterised in the acute form by the classical signs of pain (dolor), heat (calor), redness (rubor), swelling (tumour) and loss of function (functio laesa).
Intervertebral: Situated between two contiguous vertebrae.
Intervertebral disc: The intervertebral discs or nucleus pulposus are fibro-cartilaginous and lie between the vertebral bodies in the spine.
Intracranial pressure: The pressure the cerebrospinal fluid exerts on the brain.
Laminectomysurgical procedure including removal of a portion of the bone comprising a vertebra.
Leptomeninges The two delicate layers of the meninges, the arachnoid mater and pia mater (vs. The tough pachymeninx or dura mater), considered together; by this concept, the arachnoid and pia are two parts of a single layer, much like the parietal and visceral layers of a serous membrane or bursa; although separated by the subarachnoid space they are connected via the arachnoid trabeculae and become continuous where the nerves and filum terminale exit the subarachnoid space (the cerebrospinal fluid-filled space bounded by the leptomeninges).
Localised: A disease found only in the original site, with no spread to other organs.
Loculation: 1. A loculate region in an organ or tissue, or a loculate structure
Lumbar: Pertaining to the loins, the part of the back between the thorax and the pelvis.
Lymphatic system: The tissues and organs (including the bone marrow, spleen, thymus and lymph nodes) that produce and store cells that fight infection and the network of vessels that carry lymph. Lymph is an almost colourless fluid that bathes body tissues and is found in the lymphatic vessels
Meninges: The surrounding membranes the brain and spinal cord. There are three layers: the dura mater (outer), arachnoid membrane (middle) and the pia mater (inner layer).
Meningism: The symptoms and signs of meningeal irritation
Meningitis: Inflammation of the meninges.
Mononeuropathy: Disorder involving a single nerve.
Mononeuropathy multiplex: inflammation of several nerves usually in unrelated portions of the body.
Myelogram: diagnostic procedure where a radiopaque contrast dye is injected into the spinal canal.
Myoclonus: Twitching or spasm of a muscle or a group of muscles.
Myelomalacia: Softening of the spinal cord.
Myelopathy Any disease affecting the spinal cord.
Myopathy: Any disease of a muscle.
Narcotics: Originally, agents that caused somnolence or induced sleep; now, any derivative, natural or synthetic, of opium or morphine or any substance that has their effects.
Neurogenic: Arising from or caused by the nervous system.
Neuroimmunomodulation: a complex interaction between the nervous system and the immune system.  
Neuropathic: functional disturbances and/or pathological changes in the peripheral nervous system.
Neurotransmitter: Any of a group of substances that are released on excitation from the axon terminal of a presynaptic neuron of the central or peripheral nervous system and travel across the synaptic cleft to either excite or inhibit the target cell. E.g. acetylcholine, noradrenaline, adrenaline, dopamine, glycine, y aminobutyrate, glutamic acid, substance P, enkephalins, endorphins and serotonin.
Oedema: abnormally large amounts of fluid in the intercellular tissue spaces of the body, may be localised, due to venous or lymphatic obstruction or to increased vascular permeability or it may be systemic due to heart failure or renal disease.
Collections of oedema fluid are designated according to the site, for example ascites (peritoneal cavity), hydrothorax (pleural cavity) and hydropericardium (pericardial sac). Massive generalised oedema is called anasarca.
Optochiasmic: in the region of the optic chiasm, the crossover point of the two optic nerves from the back of the eyes.
Osteoporosis: A reduction in the amount of bone mass, leading to fractures after minimal trauma.
Pachymeningitis: Inflammation of the dura mater or outer membrane of the brain
Paraesthesia: an abnormal sensation, as burning, prickling, formication, etc.
Paresis: weakness (cf. Paralysis= total loss of power)
Paraparesis: weakness in the lower part of the body
Percutaneous: Performed through the skin, as injection of radiopaque material in radiological examination or the removal of tissue for biopsy accomplished by a needle.
Perineural: surrounding a nerve
Peripheral nerves: The nerves outside of the brain and spinal cord, including the autonomic, cranial, and spinal nerves.
Pia: The delicate and highly vascular membrane immediately investing the brain and spinal cord.
Polyneuropathy: A disease process involving a number of peripheral nerves.
Prolapse: The falling down or sinking, of a part or viscus, procidentia.
Prolapsed disc: abnormal protrusion (bulging), herniation or prolapse of a vertebral disc from its normal position in the vertebral column. The displaced disc may exert force on a nearby nerve root
Prognosis: forecast of the probable outcome of an attack or disease
Pseudomeningocele: an extension of the subarachnoid space into the soft tissue surrounding the central nervous system.  Unlike meningocele, pseudomeningocele is cerebrospinal fluid not bounded or confined by a biological membrane.
Radiculopathy: the radicular nerve (nerve root) is compressed by the prolapsed disk is referred to as a radiculopathy. This problem tends to occur most commonly in the cervical and lumbar spine.
Raynaud's Phenomenon: a condition causing abnormal response to cold in the extremities causing pallor, pins and needles and pain, followed by redness. 
Regional anaesthesia: Use of local anaesthetic solution(s) to produce circumscribed areas of loss of sensation; a generic term including conduction, nerve block, spinal, epidural, field block, infiltration, and topical anaesthesia.
Rheumatology: branch of medicine dealing with arthritis and related conditions
Rhinosinusogenic: originating from chronic infection in the nose/nasal sinuses
Sacral: of or pertaining to the sacrum; in the region of the sacrum.
Sacrum: The triangular-shaped bone lying between the 5th lumbar vertebra and the coccyx (tailbone).
It consists of 5 vertebrae fused together and it articulates on each side with the bones of the pelvis (ilium), forming the sacroiliac joints.
Saddle anaesthesia: loss of sensation in buttocks, perineum, and inner surfaces of the thighs.
Stenosis: Narrowing or stricture of a duct or canal. Spinal stenosis: An abnormal narrowing of the spinal canal or lateral foramina (through which nerve roots runs) that may be either congenital or acquired.
Subarachnoid haemorrhage: bleeding into the subarachnoid space; often due to a ruptured cranial aneurysm
Subarachnoid space: space between the arachnoid and pia mater, traversed by delicate fibrous trabeculae and filled with cerebrospinal fluid. Large blood vessels supplying the brain and spinal cord lie in the subarachnoid space.
Syringomyelia Syrinx, congenital: 90% associated with Arnold-Chiari; acquired: trauma, tumour, infection, haemorrhage, etc.
Sudomotor: autonomic (sympathetic) nerves that stimulate the sweat glands to activity.
Symptoms: manifestations of disease and pathological conditions, which may occur in various diseases and different organs
Systemic Lupus Erythematosus: an autoimmune condition causing a wide variety of symptoms throughout the body and often associated with a butterfly-shape facial rash. More common in women.
Sweet's syndrome: rare condition characterised by red-brown plaques and nodules, frequently painful occurring primarily on the head, neck and upper extremities.
The patients will also have fever and increased white blood cell counts (neutrophils). In approximately 10% of the patients there is an associated malignancy, most commonly acute nonlymphocytic leukaemia.
The idiopathic form (unknown cause) of Sweet's syndrome is seen more often in females following a respiratory tract infection.
Tarlov's cyst: A perineural cyst found in nerve roots of the lower spinal cord
Tinnitus, ringing, buzzing, roaring, clicking, etc. in the ears.
Theca: A sheath; a case, a capsule; thecal sac= dural sac
Thoracic: Pertaining to or affecting the chest. (thorax)
Tonicity: normal tension of tissues; in muscle, it is active resistance to stretch
Vertigo: An illusion of movement, a sensation as if the external world were revolving around the patient (objective vertigo) or as if he himself were revolving in space (subjective vertigo).