Radial Nerve: A major nerve of the upper extremity. In humans the fibers of the radial nerve originate in the lower cervical and upper thoracic spinal cord (usually C5 to T1), travel via the posterior cord of the brachial plexus, and supply motor innervation to extensor muscles of the arm and cutaneous sensory fibers to extensor regions of the arm and hand.Radial Neuropathy: Disease involving the RADIAL NERVE. Clinical features include weakness of elbow extension, elbow flexion, supination of the forearm, wrist and finger extension, and thumb abduction. Sensation may be impaired over regions of the dorsal forearm. Common sites of compression or traumatic injury include the AXILLA and radial groove of the HUMERUS.Humeral FracturesNerve 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.Radial Artery: The direct continuation of the brachial trunk, originating at the bifurcation of the brachial artery opposite the neck of the radius. Its branches may be divided into three groups corresponding to the three regions in which the vessel is situated, the forearm, wrist, and hand.Embalming: Process of preserving a dead body to protect it from decay.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.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.Brachial Plexus: The large network of nerve fibers which distributes the innervation of the upper extremity. The brachial plexus extends from the neck into the axilla. In humans, the nerves of the plexus usually originate from the lower cervical and the first thoracic spinal cord segments (C5-C8 and T1), but variations are not uncommon.Median Neuropathy: Disease involving the median nerve, from its origin at the BRACHIAL PLEXUS to its termination in the hand. Clinical features include weakness of wrist and finger flexion, forearm pronation, thenar abduction, and loss of sensation over the lateral palm, first three fingers, and radial half of the ring finger. Common sites of injury include the elbow, where the nerve passes through the two heads of the pronator teres muscle (pronator syndrome) and in the carpal tunnel (CARPAL TUNNEL SYNDROME).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.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.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.Elbow Joint: A hinge joint connecting the FOREARM to the ARM.Paralysis: A general term most often used to describe severe or complete loss of muscle strength due to motor system disease from the level of the cerebral cortex to the muscle fiber. This term may also occasionally refer to a loss of sensory function. (From Adams et al., Principles of Neurology, 6th ed, p45)Cadaver: A dead body, usually a human body.Carpometacarpal Joints: The articulations between the CARPAL BONES and the METACARPAL BONES.Nerve Block: Interruption of NEURAL CONDUCTION in peripheral nerves or nerve trunks by the injection of a local anesthetic agent (e.g., LIDOCAINE; PHENOL; BOTULINUM TOXINS) to manage or treat pain.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.Holothuria: A genus of large SEA CUCUMBERS in the family Holothuriidae possessing thick body walls, a warty body surface, and microscopic ossicles.Wrist: The region of the upper limb between the metacarpus and the FOREARM.Fracture Fixation, Internal: The use of internal devices (metal plates, nails, rods, etc.) to hold the position of a fracture in proper alignment.Pinch Strength: Force exerted when using the index finger and the thumb. It is a test for determining maximum voluntary contraction force.Thumb: The first digit on the radial side of the hand which in humans lies opposite the other four.Neural Conduction: The propagation of the NERVE IMPULSE along the nerve away from the site of an excitation stimulus.Sea Cucumbers: A class of Echinodermata characterized by long, slender bodies.Bone Plates: Implantable fracture fixation devices attached to bone fragments with screws to bridge the fracture gap and shield the fracture site from stress as bone heals. (UMDNS, 1999)Asterina: A genus of STARFISH in the family Asterinidae. They externally hold developing embryos (EMBRYO, NON-MAMMALIAN) among the spines below the oral surface.Nerve Regeneration: Renewal or physiological repair of damaged nerve tissue.Humerus: Bone in humans and primates extending from the SHOULDER JOINT to the ELBOW JOINT.Electric Stimulation: Use of electric potential or currents to elicit biological responses.Neurons, Afferent: Neurons which conduct NERVE IMPULSES to the CENTRAL NERVOUS SYSTEM.Dissection: The separation and isolation of tissues for surgical purposes, or for the analysis or study of their structures.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.Nerve Transfer: Surgical reinnervation of a denervated peripheral target using a healthy donor nerve and/or its proximal stump. The direct connection is usually made to a healthy postlesional distal portion of a non-functioning nerve or implanted directly into denervated muscle or insensitive skin. Nerve sprouts will grow from the transferred nerve into the denervated elements and establish contact between them and the neurons that formerly controlled another area.Invertebrate Hormones: Hormones produced by invertebrates, usually insects, mollusks, annelids, and helminths.Fractures, Closed: Fractures in which the break in bone is not accompanied by an external wound.Nerve Endings: Branch-like terminations of NERVE FIBERS, sensory or motor NEURONS. Endings of sensory neurons are the beginnings of afferent pathway to the CENTRAL NERVOUS SYSTEM. Endings of motor neurons are the terminals of axons at the muscle cells. Nerve endings which release neurotransmitters are called PRESYNAPTIC TERMINALS.Sural Nerve: A branch of the tibial nerve which supplies sensory innervation to parts of the lower leg and foot.Electromyography: Recording of the changes in electric potential of muscle by means of surface or needle electrodes.Peripheral Nerve Injuries: Injuries to the PERIPHERAL NERVES.Facial Nerve: The 7th cranial nerve. The facial nerve has two parts, the larger motor root which may be called the facial nerve proper, and the smaller intermediate or sensory root. Together they provide efferent innervation to the muscles of facial expression and to the lacrimal and SALIVARY GLANDS, and convey afferent information for TASTE from the anterior two-thirds of the TONGUE and for TOUCH from the EXTERNAL EAR.Nerve Crush: Treatment of muscles and nerves under pressure as a result of crush injuries.Forearm: Part of the arm in humans and primates extending from the ELBOW to the WRIST.Arm: The superior part of the upper extremity between the SHOULDER and the ELBOW.Tibial Nerve: The medial terminal branch of the sciatic nerve. The tibial nerve fibers originate in lumbar and sacral spinal segments (L4 to S2). They supply motor and sensory innervation to parts of the calf and foot.H-Reflex: A monosynaptic reflex elicited by stimulating a nerve, particularly the tibial nerve, with an electric shock.Keratotomy, Radial: A procedure to surgically correct REFRACTIVE ERRORS by cutting radial slits into the CORNEA to change its refractive properties.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.Spinal Nerves: The 31 paired peripheral nerves formed by the union of the dorsal and ventral spinal roots from each spinal cord segment. The spinal nerve plexuses and the spinal roots are also included.Elbow: Region of the body immediately surrounding and including the ELBOW JOINT.Evoked Potentials: Electrical responses recorded from nerve, muscle, SENSORY RECEPTOR, or area of the CENTRAL NERVOUS SYSTEM following stimulation. They range from less than a microvolt to several microvolts. The evoked potential can be auditory (EVOKED POTENTIALS, AUDITORY), somatosensory (EVOKED POTENTIALS, SOMATOSENSORY), visual (EVOKED POTENTIALS, VISUAL), or motor (EVOKED POTENTIALS, MOTOR), or other modalities that have been reported.Hand: The distal part of the arm beyond the wrist in humans and primates, that includes the palm, fingers, and thumb.Forelimb: A front limb of a quadruped. (The Random House College Dictionary, 1980)Motor Neurons: Neurons which activate MUSCLE CELLS.

Gating of transmission in climbing fibre paths to cerebellar cortical C1 and C3 zones in the rostral paramedian lobule during locomotion in the cat. (1/169)

1. Climbing fibre field potentials evoked by low intensity (non-noxious) electrical stimulation of the ipsilateral superficial radial nerve have been recorded in the rostral paramedian lobule (PML) in awake cats. Chronically implanted microwires were used to monitor the responses at eight different C1 and C3 zone sites during quiet rest and during steady walking on a moving belt. The latency and other characteristics of the responses identified them as mediated mainly via the dorsal funiculus-spino-olivocerebellar path (DF-SOCP). 2. At each site, mean size of response (measured as the area under the field, in mV ms) varied systematically during the step cycle without parallel fluctuations in size of the peripheral nerve volley. Largest responses occurred overwhelmingly during the stance phase of the step cycle in the ipsilateral forelimb while smallest responses occurred most frequently during swing. 3. Simultaneous recording from pairs of C1 zone sites located in the anterior lobe (lobule V) and C1 or C3 zone sites in rostral PML revealed markedly different patterns of step-related modulation. 4. The findings shed light on the extent to which the SOCPs projecting to different parts of a given zone can be regarded as functionally uniform and have implications as to their reliability as channels for conveying peripheral signals to the cerebellum during locomotion.  (+info)

Sonographic detection of radial nerve entrapment within a humerus fracture. (2/169)

Radial neuropathy is frequently associated with fracture of the middle third of the humerus owing to the course of the nerve adjacent to the humeral shaft. The prevalence varies from 2 to 18% of humeral fractures. The therapeutic management is still controversial. Some authors recommend initial surgical exploration, whereas others prefer observation and intervention only if the injured nerve failed to recover after a period of more than 4 months. According to the literature, verification of an entrapped radial nerve in a fracture gap requires surgical exploration, but diagnostic tools to verify the existence of a pathologic condition are limited. We describe the sonographic findings of an entrapped radial nerve and review the literature regarding diagnosis and treatment of entrapped radial nerve in cases of humeral fracture.  (+info)

Safety of the limited open technique of bone-transfixing threaded-pin placement for external fixation of distal radial fractures: a cadaver study. (3/169)

OBJECTIVE: To examine the safety of threaded-pin placement for fixation of distal radial fractures using a limited open approach. DESIGN: A cadaver study. METHODS: Four-millimetre Schanz threaded pins were inserted into the radius and 3-mm screw pins into the second metacarpal of 20 cadaver arms. Each threaded pin was inserted in the dorsoradial oblique plane through a limited open, 5- to 10-mm longitudinal incision. Open exploration of the threaded-pin sites was then carried out. OUTCOME MEASURES: Injury to nerves, muscles and tendons and the proximity of these structures to the threaded pins. RESULTS: There were no injuries to the extensor tendons, superficial radial or lateral antebrachial nerves of the forearm, or to the soft tissues overlying the metacarpal. The lateral antebrachial nerve was the closest nerve to the radial pins and a branch of the superficial radial nerve was closest to the metacarpal pins. The superficial radial nerve was not close to the radial pins. CONCLUSION: Limited open threaded-pin fixation of distal radial fractures in the dorsolateral plane appears to be safe.  (+info)

Secondary hyperalgesia to punctate mechanical stimuli. Central sensitization to A-fibre nociceptor input. (4/169)

Tissue injury induces enhanced pain sensation to light touch and punctate stimuli in adjacent, uninjured skin (secondary hyperalgesia). Whereas hyperalgesia to light touch (allodynia) is mediated by A-fibre low-threshold mechanoreceptors, hyperalgesia to punctate stimuli may be mediated by A- or C-fibre nociceptors. To disclose the relative contributions of A- and C-fibres to the hyperalgesia to punctate stimuli, the superficial radial nerve was blocked by pressure at the wrist in nine healthy subjects. Secondary hyperalgesia was induced by intradermal injection of 40 microg capsaicin, and pain sensitivity in adjacent skin was tested with 200 micron diameter probes (35-407 mN). The progress of conduction blockade was monitored by touch, cold, warm and first pain detection and by compound sensory nerve action potential. When A-fibre conduction was blocked completely but C-fibre conduction was fully intact, pricking pain to punctate stimuli was reduced by 75%, but burning pain to capsaicin injection remained unchanged. In normal skin without A-fibre blockade, pain ratings to the punctate probes increased significantly by a factor of two after adjacent capsaicin injection. In contrast, pain ratings to the punctate probes were not increased after capsaicin injection when A-fibre conduction was selectively blocked. However, hyperalgesia to punctate stimuli was detectable immediately after block release, when A-fibre conduction returned to normal. In conclusion, the pricking pain to punctate stimuli is predominantly mediated by A-fibre nociceptors. In secondary hyperalgesia, this pathway is heterosynaptically facilitated by conditioning C-fibre input. Thus, secondary hyperalgesia to punctate stimuli is induced by nociceptive C-fibre discharge but mediated by nociceptive A-fibres.  (+info)

Distribution of presynaptic inhibition on type-identified motoneurones in the extensor carpi radialis pool in man. (5/169)

The question was addressed as to whether the magnitude of Ia presynaptic inhibition might depend on the type of motor unit activated during voluntary contraction in the wrist extensor muscles. For this purpose, we investigated the effects of applying electrical stimulation to the median nerve on the responses of 25 identified motor units to radial nerve stimulation delivered 20 ms after a conditioning stimulation. The reflex responses of the motor units yielded peaks in the post-stimulus time histograms with latencies compatible with monosynaptic activation. Although median nerve stimulation did not affect the motoneurone net excitatory drive assessed from the mean duration of the inter-spike interval, it led to a decrease in the contents of the first two 0.25 ms bins of the peak. This decrease may be consistent with the Ia presynaptic inhibition known to occur under these stimulation conditions. In the trials in which the median nerve was being stimulated, the finding that the response probability of the motor units, even in their monosynaptic components, tended to increase as their force threshold and their macro-potential area increased and as their twitch contraction time decreased suggests that the median nerve stimulation may have altered the efficiency with which the Ia inputs recruited the motoneurones in the pool. These effects were consistently observed in seven pairs of motor units each consisting of one slow and one fast contracting motor unit which were simultaneously tested, which suggests that the magnitude of the Ia presynaptic inhibition may depend on the type of motor unit tested rather than on the motoneurone pool excitatory drive. The present data suggest for the first time that in humans, the Ia presynaptic inhibition may show an upward gradient working from fast to slow contracting motor units which is able to compensate for the downward gradient in monosynaptic reflex excitation from 'slow' to 'fast' motor units. From a functional point of view, a weaker Ia presynaptic inhibition acting on the fast contracting motor units may contribute to improving the proprioceptive assistance to the wrist myotatic unit when the contraction force has to be increased.  (+info)

Abnormal reciprocal inhibition between antagonist muscles in Parkinson's disease. (6/169)

Disynaptic Ia reciprocal inhibition acts, at the spinal level, by actively inhibiting antagonist motor neurons and reducing the inhibition of agonist motor neurons. The deactivation of this pathway in Parkinson's disease is still debated. Disynaptic reciprocal inhibition of H reflexes in the forearm flexor muscles was examined in 15 control subjects and 16 treated parkinsonian patients at rest and at the onset of a voluntary wrist flexion. Two patients were reassessed 18 h after withdrawal of antiparkinsonian medication. At rest, the level of Ia reciprocal inhibition between the wrist antagonist muscles was not significantly different between patients and controls. In contrast, clear abnormalities of this inhibition were revealed by voluntary movements in the patients. In normal subjects, at the onset of a wrist flexion, Ia reciprocal inhibition showed a large decrease, and we argue that this decrease is supraspinal in origin. On the less affected sides of the patients the descending modulation was still present but lower than in controls; on the more affected sides this modulation had vanished almost completely. These movement-induced abnormalities of disynaptic Ia reciprocal inhibition were closely associated with Parkinson's disease but were probably not dependent on L-dopa. They could play a role in the disturbances of precise voluntary movements observed in Parkinson's disease.  (+info)

Cryosurgery for chronic injuries of the cutaneous nerve in the upper limb. Analysis of a new open technique. (7/169)

We have treated six patients with chronic pain following nerve injury using a cryosurgical probe. All had a significant return of hand function and improvement of pain during a mean follow-up of 13.5 months. Open visualisation of the injured nervous tissue is essential for patients undergoing this technique. Four patients regained normal sensation in the dermatome of the previously injured nerve.  (+info)

External fixation of open humerus fractures. (8/169)

Fifteen patients with open shaft of humerus fractures were treated with a monolateral external fixator. Nine patients presented with nerve palsies. Two radial nerves were disrupted and required grafting. Of the seven others, six spontaneously recovered and one brachial plexus partially improved. All fractures healed. The average duration of external fixation was 21 weeks. Four patients required additional procedures prior to healing (external fixator reapplication-2, plating and bone grafting-2). Two of these four experienced breakage of 4.5 mm external fixation pins. Eight patients developed pin tract infections, which all resolved with local care and antibiotics. Thirteen patients were contacted at an average of 63 months after injury. Eleven reported they were satisfied with their result, nine had no functional limits, and eight reported no pain.  (+info)

  • Any problems with hand, wrist, or triceps movement and any arm sensation problems may be indicative of possible radial nerve dysfunction. (muslimselfportrait.info)
  • Splinting allows avoidance of the forceful or repeated motion of supination or wrist dorsiflexion, reducing pressure on the nerve. (merckmanuals.com)
  • Background: Poor prognosis of radial nerve repair in elderly patients may be due to changes in intraneural anatomy with age. (elsevier.com)
  • The present study is to find the fascicular pattern of radial nerve (at antecubital fossa), microanatomic morphometric characteristics of its connective tissue components and changes with age and study of intraneural sympathetic fiber content. (elsevier.com)
  • In elderly cases, there is significant increase in total radial nerve cross-sectional area due to an increase in its non-fascicular connective tissue area and excessive adipose tissue deposition in interfascicular domains. (elsevier.com)
  • Methods: Twenty human (21-87 years) cadaveric radial nerves have been collected from antecubital fossa and the study has been performed at magnifications (10×, 20× and 40× objective) after routine histological (hematoxylin & eosin stain) processing was done for morphometric analysis (total cross-sectional, fascicular and non-fascicular area) and immunohistochemical (tyrosine hydroxylase) processing for sympathetic fibers. (elsevier.com)
  • Mase T, Ishibazawa A, Nagaoka T, Yokota H, Yoshida A (2016) Radial peripapillary capillary network visualized using wide-field montage optical coherence tomography angiography. (springer.com)
  • Sep 15, 2016 - How nerve gliding reduces pain from numerous causes. (koop.com.my)
  • Measurement of pressure pain threshold in the lateral epicondyle, radial nerve in the spiral groove, C5-C6 zygapophyseal joints, and the tibialis anterior muscle. (clinicaltrials.gov)
  • At the level of the lateral epicondyle, between the lateral epicondyle and muscu-lospiral groove, the radial nerve divides into superficial and deep branches. (pharmacologicalsciences.us)
  • Typically, patients will have intense pain over the lateral epicondyle that radiates distally and radially towards the radial styloid and thumb. (clinicaladvisor.com)
  • Interestingly, it has been the experience of this author that the epicenter of painful stimulus can be located by taking 80% of the transepicondylar distance (the distance between the medial and lateral humeral epicondyles) and applying pressure at this distance from the lateral epicondyle pointing towards the radial styloid. (clinicaladvisor.com)
  • The nerve surfaces from the septum anterior to the lateral epicondyle just lateral to the lateral edge of the brachialis, and medial to the brachioradialis. (functionalanatomyblog.com)
  • Create healthcare diagrams like this example called Muscle Innervation of the Radial Nerve in minutes with SmartDraw. (smartdraw.com)
  • needle is inserted until a paraesthesia is elicited in the distribution of innervation of the radial nerve. (pharmacologicalsciences.us)
  • Which specialist consultations are beneficial to patients with radial mononeuropathy? (medscape.com)
  • Diagnosis Information The patient's diagnosis in this case study is lesion of the radial nerve.¹ The International Classifications of Diseases 9th Revision, ICD-9-CM 354.3 will be replaced by an equivalent ICD-10-CM code (or codes) when the United States transitions from ICD-9-CM to ICD-10-CM on October 1, 2015. (bartleby.com)
  • Atypical double nerve lesion after humeral fracture: diagnosis by ultrasound. (medscape.com)
  • Note the enlarged costal nerves below the skin that were affected by the disease and which were supplying the leprous lesion. (cdc.gov)
  • This revealed a neuropraxia of her left radial nerve at the spiral groove. (bmj.com)
  • The components of the eighth cranial nerve (CN VIII) carrying axons that convey information regarding sound and balance between the spiral ganglion in the inner ear and the cochlear nuclei in the brainstem. (tabers.com)
  • To analyse the expansion of radial peripapillary capillary (RPC) network with optical coherence tomography angiography (OCT-A) in normal human eyes and correlate RPC density with retinal nerve fibre layer thickness (RNFLT) at various distances from the optic nerve head (ONH) edge. (springer.com)
  • Yu PK, Cringle SJ, Yu DY (2014) Correlation between the radial peripapillary capillaries and the retinal nerve fibre layer in the normal human retina. (springer.com)