Nerve Compression Syndromes: Mechanical compression of nerves or nerve roots from internal or external causes. These may result in a conduction block to nerve impulses (due to MYELIN SHEATH dysfunction) or axonal loss. The nerve and nerve sheath injuries may be caused by ISCHEMIA; INFLAMMATION; or a direct mechanical effect.Ulnar Nerve Compression Syndromes: Ulnar neuropathies caused by mechanical compression of the nerve at any location from its origin at the BRACHIAL PLEXUS to its terminations in the hand. Common sites of compression include the retroepicondylar groove, cubital tunnel at the elbow (CUBITAL TUNNEL SYNDROME), and Guyon's canal at the wrist. Clinical features depend on the site of injury, but may include weakness or paralysis of wrist flexion, finger flexion, and ulnar innervated intrinsic hand muscles, and impaired sensation over the ulnar aspect of the hand, fifth finger, and ulnar half of the ring finger. (Joynt, Clinical Neurology, 1995, Ch51, p43)Celiac Artery: The arterial trunk that arises from the abdominal aorta and after a short course divides into the left gastric, common hepatic and splenic arteries.Iliac Vein: A vein on either side of the body which is formed by the union of the external and internal iliac veins and passes upward to join with its fellow of the opposite side to form the inferior vena cava.Decompression, Surgical: A surgical operation for the relief of pressure in a body compartment or on a body part. (From Dorland, 28th ed)Syndrome: A characteristic symptom complex.Celiac Plexus: A complex network of nerve fibers including sympathetic and parasympathetic efferents and visceral afferents. The celiac plexus is the largest of the autonomic plexuses and is located in the abdomen surrounding the celiac and superior mesenteric arteries.Ligaments: Shiny, flexible bands of fibrous tissue connecting together articular extremities of bones. They are pliant, tough, and inextensile.Constriction, Pathologic: The condition of an anatomical structure's being constricted beyond normal dimensions.Median Nerve: A major nerve of the upper extremity. In humans, the fibers of the median nerve originate in the lower cervical and upper thoracic spinal cord (usually C6 to T1), travel via the brachial plexus, and supply sensory and motor innervation to parts of the forearm and hand.Carpal Tunnel Syndrome: Entrapment of the MEDIAN NERVE in the carpal tunnel, which is formed by the flexor retinaculum and the CARPAL BONES. This syndrome may be associated with repetitive occupational trauma (CUMULATIVE TRAUMA DISORDERS); wrist injuries; AMYLOID NEUROPATHIES; rheumatoid arthritis (see ARTHRITIS, RHEUMATOID); ACROMEGALY; PREGNANCY; and other conditions. Symptoms include burning pain and paresthesias involving the ventral surface of the hand and fingers which may radiate proximally. Impairment of sensation in the distribution of the median nerve and thenar muscle atrophy may occur. (Joynt, Clinical Neurology, 1995, Ch51, p45)Tibial Neuropathy: Disease of the TIBIAL NERVE (also referred to as the posterior tibial nerve). The most commonly associated condition is the TARSAL TUNNEL SYNDROME. However, LEG INJURIES; ISCHEMIA; and inflammatory conditions (e.g., COLLAGEN DISEASES) may also affect the nerve. Clinical features include PARALYSIS of plantar flexion, ankle inversion and toe flexion as well as loss of sensation over the sole of the foot. (From Joynt, Clinical Neurology, 1995, Ch51, p32)Ulnar Nerve: A major nerve of the upper extremity. In humans, the fibers of the ulnar nerve originate in the lower cervical and upper thoracic spinal cord (usually C7 to T1), travel via the medial cord of the brachial plexus, and supply sensory and motor innervation to parts of the hand and forearm.Cubital Tunnel Syndrome: Compression of the ULNAR NERVE in the cubital tunnel, which is formed by the two heads of the flexor carpi ulnaris muscle, humeral-ulnar aponeurosis, and medial ligaments of the elbow. This condition may follow trauma or occur in association with processes which produce nerve enlargement or narrowing of the canal. Manifestations include elbow pain and PARESTHESIA radiating distally, weakness of ulnar innervated intrinsic hand muscles, and loss of sensation over the hypothenar region, fifth finger, and ulnar aspect of the ring finger. (Joynt, Clinical Neurology, 1995, Ch51, p43)Peroneal Neuropathies: Disease involving the common PERONEAL NERVE or its branches, the deep and superficial peroneal nerves. Lesions of the deep peroneal nerve are associated with PARALYSIS of dorsiflexion of the ankle and toes and loss of sensation from the web space between the first and second toe. Lesions of the superficial peroneal nerve result in weakness or paralysis of the peroneal muscles (which evert the foot) and loss of sensation over the dorsal and lateral surface of the leg. Traumatic injury to the common peroneal nerve near the head of the FIBULA is a relatively common cause of this condition. (From Joynt, Clinical Neurology, 1995, Ch51, p31)Thoracic Outlet Syndrome: A neurovascular syndrome associated with compression of the BRACHIAL PLEXUS; SUBCLAVIAN ARTERY; and SUBCLAVIAN VEIN at the superior thoracic outlet. This may result from a variety of anomalies such as a CERVICAL RIB, anomalous fascial bands, and abnormalities of the origin or insertion of the anterior or medial scalene muscles. Clinical features may include pain in the shoulder and neck region which radiates into the arm, PARESIS or PARALYSIS of brachial plexus innervated muscles, PARESTHESIA, loss of sensation, reduction of arterial pulses in the affected extremity, ISCHEMIA, and EDEMA. (Adams et al., Principles of Neurology, 6th ed, pp214-5).Compartment Syndromes: Conditions in which increased pressure within a limited space compromises the BLOOD CIRCULATION and function of tissue within that space. Some of the causes of increased pressure are TRAUMA, tight dressings, HEMORRHAGE, and exercise. Sequelae include nerve compression (NERVE COMPRESSION SYNDROMES); PARALYSIS; and ISCHEMIC CONTRACTURE.Facial Nerve Diseases: Diseases of the facial nerve or nuclei. Pontine disorders may affect the facial nuclei or nerve fascicle. The nerve may be involved intracranially, along its course through the petrous portion of the temporal bone, or along its extracranial course. Clinical manifestations include facial muscle weakness, loss of taste from the anterior tongue, hyperacusis, and decreased lacrimation.Phlebography: Radiographic visualization or recording of a vein after the injection of contrast medium.Abdominal Pain: Sensation of discomfort, distress, or agony in the abdominal region.Arterial Occlusive Diseases: Pathological processes which result in the partial or complete obstruction of ARTERIES. They are characterized by greatly reduced or absence of blood flow through these vessels. They are also known as arterial insufficiency.Sciatic Nerve: A nerve which originates in the lumbar and sacral spinal cord (L4 to S3) and supplies motor and sensory innervation to the lower extremity. The sciatic nerve, which is the main continuation of the sacral plexus, is the largest nerve in the body. It has two major branches, the TIBIAL NERVE and the PERONEAL NERVE.Electrodiagnosis: Diagnosis of disease states by recording the spontaneous electrical activity of tissues or organs or by the response to stimulation of electrically excitable tissue.Peripheral Vascular Diseases: Pathological processes involving any one of the BLOOD VESSELS in the vasculature outside the HEART.Sciatic Neuropathy: Disease or damage involving the SCIATIC NERVE, which divides into the PERONEAL NERVE and TIBIAL NERVE (see also PERONEAL NEUROPATHIES and TIBIAL NEUROPATHY). Clinical manifestations may include SCIATICA or pain localized to the hip, PARESIS or PARALYSIS of posterior thigh muscles and muscles innervated by the peroneal and tibial nerves, and sensory loss involving the lateral and posterior thigh, posterior and lateral leg, and sole of the foot. The sciatic nerve may be affected by trauma; ISCHEMIA; COLLAGEN DISEASES; and other conditions. (From Adams et al., Principles of Neurology, 6th ed, p1363)Neural Conduction: The propagation of the NERVE IMPULSE along the nerve away from the site of an excitation stimulus.Wrist Joint: The joint that is formed by the distal end of the RADIUS, the articular disc of the distal radioulnar joint, and the proximal row of CARPAL BONES; (SCAPHOID BONE; LUNATE BONE; triquetral bone).Optic Nerve Diseases: Conditions which produce injury or dysfunction of the second cranial or optic nerve, which is generally considered a component of the central nervous system. Damage to optic nerve fibers may occur at or near their origin in the retina, at the optic disk, or in the nerve, optic chiasm, optic tract, or lateral geniculate nuclei. Clinical manifestations may include decreased visual acuity and contrast sensitivity, impaired color vision, and an afferent pupillary defect.Ligaments, Articular: Fibrous cords of CONNECTIVE TISSUE that attach bones to each other and hold together the many types of joints in the body. Articular ligaments are strong, elastic, and allow movement in only specific directions, depending on the individual joint.Data Compression: Information application based on a variety of coding methods to minimize the amount of data to be stored, retrieved, or transmitted. Data compression can be applied to various forms of data, such as images and signals. It is used to reduce costs and increase efficiency in the maintenance of large volumes of data.Spinal Cord Compression: Acute and chronic conditions characterized by external mechanical compression of the SPINAL CORD due to extramedullary neoplasm; EPIDURAL ABSCESS; SPINAL FRACTURES; bony deformities of the vertebral bodies; and other conditions. Clinical manifestations vary with the anatomic site of the lesion and may include localized pain, weakness, sensory loss, incontinence, and impotence.Stockings, Compression: Tight coverings for the foot and leg that are worn to aid circulation in the legs, and prevent the formation of EDEMA and DEEP VEIN THROMBOSIS. PNEUMATIC COMPRESSION STOCKINGS serve a similar purpose especially for bedridden patients, and following surgery.Peripheral Nerves: The nerves outside of the brain and spinal cord, including the autonomic, cranial, and spinal nerves. Peripheral nerves contain non-neuronal cells and connective tissue as well as axons. The connective tissue layers include, from the outside to the inside, the epineurium, the perineurium, and the endoneurium.Fractures, Compression: Crumbling or smashing of cancellous BONE by forces acting parallel to the long axis of bone. It is applied particularly to vertebral body fractures (SPINAL FRACTURES). (Blauvelt and Nelson, A Manual of Orthopedic Terminology, 1994, p4)Optic Nerve: The 2nd cranial nerve which conveys visual information from the RETINA to the brain. The nerve carries the axons of the RETINAL GANGLION CELLS which sort at the OPTIC CHIASM and continue via the OPTIC TRACTS to the brain. The largest projection is to the lateral geniculate nuclei; other targets include the SUPERIOR COLLICULI and the SUPRACHIASMATIC NUCLEI. Though known as the second cranial nerve, it is considered part of the CENTRAL NERVOUS SYSTEM.Nerve Fibers: Slender processes of NEURONS, including the AXONS and their glial envelopes (MYELIN SHEATH). Nerve fibers conduct nerve impulses to and from the CENTRAL NERVOUS SYSTEM.Palmitic Acids: A group of 16-carbon fatty acids that contain no double bonds.Cerebrospinal Fluid Pressure: Manometric pressure of the CEREBROSPINAL FLUID as measured by lumbar, cerebroventricular, or cisternal puncture. Within the cranial cavity it is called INTRACRANIAL PRESSURE.Pressure: A type of stress exerted uniformly in all directions. Its measure is the force exerted per unit area. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Extracellular Fluid: The fluid of the body that is outside of CELLS. It is the external environment for the cells.Perforator Flap: A mass of tissue for transplantation that includes the skin and/or the SUBCUTANEOUS FAT, and the perforating blood vessel that traverses the underlying tissue to supply blood to the skin. Perforator flaps are named after the anatomical region or muscle from where they are transplanted and/or the perforating blood vessel.Diet Fads: Diets which become fashionable, but which are not necessarily nutritious.(Lehninger 1982, page 484)Ketogenic Diet: A course of food intake that is high in FATS and low in CARBOHYDRATES. This diet provides sufficient PROTEINS for growth but insufficient amount of carbohydrates for the energy needs of the body. A ketogenic diet generates 80-90% of caloric requirements from fats and the remainder from proteins.Hindlimb: Either of two extremities of four-footed non-primate land animals. It usually consists of a FEMUR; TIBIA; and FIBULA; tarsals; METATARSALS; and TOES. (From Storer et al., General Zoology, 6th ed, p73)Cellular Phone: Analog or digital communications device in which the user has a wireless connection from a telephone to a nearby transmitter. It is termed cellular because the service area is divided into multiple "cells." As the user moves from one cell area to another, the call is transferred to the local transmitter.Femoral Nerve: A nerve originating in the lumbar spinal cord (usually L2 to L4) and traveling through the lumbar plexus to provide motor innervation to extensors of the thigh and sensory innervation to parts of the thigh, lower leg, and foot, and to the hip and knee joints.Femoral Neuropathy: Disease involving the femoral nerve. The femoral nerve may be injured by ISCHEMIA (e.g., in association with DIABETIC NEUROPATHIES), nerve compression, trauma, COLLAGEN DISEASES, and other disease processes. Clinical features include MUSCLE WEAKNESS or PARALYSIS of hip flexion and knee extension, ATROPHY of the QUADRICEPS MUSCLE, reduced or absent patellar reflex, and impaired sensation over the anterior and medial thigh.GermanyDens in Dente: Anomaly of the tooth, found chiefly in upper lateral incisors. It is characterized by invagination of the enamel at the incisal edge.Arthropod Proteins: Proteins synthesized by organisms belonging to the phylum ARTHROPODA. Included in this heading are proteins from the subdivisions ARACHNIDA; CRUSTACEA; and HORSESHOE CRABS. Note that a separate heading for INSECT PROTEINS is listed under this heading.Antigens, Dermatophagoides: Antigens from the house dust mites (DERMATOPHAGOIDES), mainly D. farinae and D. pteronyssinus. They are proteins, found in mite feces or mite extracts, that can cause ASTHMA and other allergic diseases such as perennial rhinitis (RHINITIS, ALLERGIC, PERENNIAL) and atopic dermatitis (DERMATITIS, ATOPIC). More than 11 groups of Dermatophagoides ALLERGENS have been defined. Group I allergens, such as Der f I and Der p I from the above two species, are among the strongest mite immunogens in humans.Mites: Any arthropod of the subclass ACARI except the TICKS. They are minute animals related to the spiders, usually having transparent or semitransparent bodies. They may be parasitic on humans and domestic animals, producing various irritations of the skin (MITE INFESTATIONS). Many mite species are important to human and veterinary medicine as both parasite and vector. Mites also infest plants.Catheter Ablation: Removal of tissue with electrical current delivered via electrodes positioned at the distal end of a catheter. Energy sources are commonly direct current (DC-shock) or alternating current at radiofrequencies (usually 750 kHz). The technique is used most often to ablate the AV junction and/or accessory pathways in order to interrupt AV conduction and produce AV block in the treatment of various tachyarrhythmias.Dermatophagoides farinae: Species of American house dust mite, in the family PYROGLYPHIDAE.