Peroneal Nerve: The lateral of the two terminal branches of the sciatic nerve. The peroneal (or fibular) nerve provides motor and sensory innervation to parts of the leg and foot.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)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.Sural Nerve: A branch of the tibial nerve which supplies sensory innervation to parts of the lower leg and foot.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.Knee Dislocation: Slippage of the FEMUR off the TIBIA.Foot: The distal extremity of the leg in vertebrates, consisting of the tarsus (ANKLE); METATARSUS; phalanges; and the soft tissues surrounding these bones.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.Neural Conduction: The propagation of the NERVE IMPULSE along the nerve away from the site of an excitation stimulus.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.Nerve Regeneration: Renewal or physiological repair of damaged nerve tissue.Sympathetic Nervous System: The thoracolumbar division of the autonomic nervous system. Sympathetic preganglionic fibers originate in neurons of the intermediolateral column of the spinal cord and project to the paravertebral and prevertebral ganglia, which in turn project to target organs. The sympathetic nervous system mediates the body's response to stressful situations, i.e., the fight or flight reactions. It often acts reciprocally to the parasympathetic system.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)Peripheral Nervous System Diseases: Diseases of the peripheral nerves external to the brain and spinal cord, which includes diseases of the nerve roots, ganglia, plexi, autonomic nerves, sensory nerves, and motor nerves.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 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.Implantable Neurostimulators: Surgically placed electric conductors through which ELECTRIC STIMULATION of nerve tissue is delivered.Neuroma: A tumor made up of nerve cells and nerve fibers. (Dorland, 27th ed)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.Electromyography: Recording of the changes in electric potential of muscle by means of surface or needle electrodes.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.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.Gait Disorders, Neurologic: Gait abnormalities that are a manifestation of nervous system dysfunction. These conditions may be caused by a wide variety of disorders which affect motor control, sensory feedback, and muscle strength including: CENTRAL NERVOUS SYSTEM DISEASES; PERIPHERAL NERVOUS SYSTEM DISEASES; NEUROMUSCULAR DISEASES; or MUSCULAR DISEASES.Peripheral Nerve Injuries: Injuries to the PERIPHERAL NERVES.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.H-Reflex: A monosynaptic reflex elicited by stimulating a nerve, particularly the tibial nerve, with an electric shock.Fibula: The bone of the lower leg lateral to and smaller than the tibia. In proportion to its length, it is the most slender of the long bones.Electric Stimulation: Use of electric potential or currents to elicit biological responses.Ankle Joint: The joint that is formed by the inferior articular and malleolar articular surfaces of the TIBIA; the malleolar articular surface of the FIBULA; and the medial malleolar, lateral malleolar, and superior surfaces of the TALUS.Walkers: Walking aids generally having two handgrips and four legs.Leg: The inferior part of the lower extremity between the KNEE and the ANKLE.Tendon Transfer: Surgical procedure by which a tendon is incised at its insertion and placed at an anatomical site distant from the original insertion. The tendon remains attached at the point of origin and takes over the function of a muscle inactivated by trauma or disease.Muscles: Contractile tissue that produces movement in animals.Motor Neurons: Neurons which activate MUSCLE CELLS.Muscle, Skeletal: A subtype of striated muscle, attached by TENDONS to the SKELETON. Skeletal muscles are innervated and their movement can be consciously controlled. They are also called voluntary muscles.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.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.Transcutaneous Electric Nerve Stimulation: The use of specifically placed small electrodes to deliver electrical impulses across the SKIN to relieve PAIN. It is used less frequently to produce ANESTHESIA.Ankle: The region of the lower limb between the FOOT and the LEG.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.Neurons, Afferent: Neurons which conduct NERVE IMPULSES to the CENTRAL NERVOUS SYSTEM.Wavelet Analysis: Signal and data processing method that uses decomposition of wavelets to approximate, estimate, or compress signals with finite time and frequency domains. It represents a signal or data in terms of a fast decaying wavelet series from the original prototype wavelet, called the mother wavelet. This mathematical algorithm has been adopted widely in biomedical disciplines for data and signal processing in noise removal and audio/image compression (e.g., EEG and MRI).Reflex: An involuntary movement or exercise of function in a part, excited in response to a stimulus applied to the periphery and transmitted to the brain or spinal cord.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.Axons: Nerve fibers that are capable of rapidly conducting impulses away from the neuron cell body.Dissection: The separation and isolation of tissues for surgical purposes, or for the analysis or study of their structures.Diabetic Neuropathies: Peripheral, autonomic, and cranial nerve disorders that are associated with DIABETES MELLITUS. These conditions usually result from diabetic microvascular injury involving small blood vessels that supply nerves (VASA NERVORUM). Relatively common conditions which may be associated with diabetic neuropathy include third nerve palsy (see OCULOMOTOR NERVE DISEASES); MONONEUROPATHY; mononeuropathy multiplex; diabetic amyotrophy; a painful POLYNEUROPATHY; autonomic neuropathy; and thoracoabdominal neuropathy. (From Adams et al., Principles of Neurology, 6th ed, p1325)Nerve Growth Factor: NERVE GROWTH FACTOR is the first of a series of neurotrophic factors that were found to influence the growth and differentiation of sympathetic and sensory neurons. It is comprised of alpha, beta, and gamma subunits. The beta subunit is responsible for its growth stimulating activity.Trigeminal Nerve: The 5th and largest cranial nerve. The trigeminal nerve is a mixed motor and sensory nerve. The larger sensory part forms the ophthalmic, mandibular, and maxillary nerves which carry afferents sensitive to external or internal stimuli from the skin, muscles, and joints of the face and mouth and from the teeth. Most of these fibers originate from cells of the TRIGEMINAL GANGLION and project to the TRIGEMINAL NUCLEUS of the brain stem. The smaller motor part arises from the brain stem trigeminal motor nucleus and innervates the muscles of mastication.Nerve Growth Factors: Factors which enhance the growth potentialities of sensory and sympathetic nerve cells.Skin: The outer covering of the body that protects it from the environment. It is composed of the DERMIS and the EPIDERMIS.Phrenic Nerve: The motor nerve of the diaphragm. The phrenic nerve fibers originate in the cervical spinal column (mostly C4) and travel through the cervical plexus to the diaphragm.Muscle Spindles: Skeletal muscle structures that function as the MECHANORECEPTORS responsible for the stretch or myotactic reflex (REFLEX, STRETCH). They are composed of a bundle of encapsulated SKELETAL MUSCLE FIBERS, i.e., the intrafusal fibers (nuclear bag 1 fibers, nuclear bag 2 fibers, and nuclear chain fibers) innervated by SENSORY NEURONS.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.Muscle Contraction: A process leading to shortening and/or development of tension in muscle tissue. Muscle contraction occurs by a sliding filament mechanism whereby actin filaments slide inward among the myosin filaments.Cranial Nerves: Twelve pairs of nerves that carry general afferent, visceral afferent, special afferent, somatic efferent, and autonomic efferent fibers.Spinal Nerve Roots: Paired bundles of NERVE FIBERS entering and leaving the SPINAL CORD at each segment. The dorsal and ventral nerve roots join to form the mixed segmental spinal nerves. The dorsal roots are generally afferent, formed by the central projections of the spinal (dorsal root) ganglia sensory cells, and the ventral roots are efferent, comprising the axons of spinal motor and PREGANGLIONIC AUTONOMIC FIBERS.Posterior Cruciate Ligament: A strong ligament of the knee that originates from the anterolateral surface of the medial condyle of the femur, passes posteriorly and inferiorly between the condyles, and attaches to the posterior intercondylar area of the tibia.Muscle Denervation: The resection or removal of the innervation of a muscle or muscle tissue.Action Potentials: Abrupt changes in the membrane potential that sweep along the CELL MEMBRANE of excitable cells in response to excitation stimuli.Orthotic Devices: Apparatus used to support, align, prevent, or correct deformities or to improve the function of movable parts of the body.Ophthalmic Nerve: A sensory branch of the trigeminal (5th cranial) nerve. The ophthalmic nerve carries general afferents from the superficial division of the face including the eyeball, conjunctiva, upper eyelid, upper nose, nasal mucosa, and scalp.Patient Positioning: Moving a patient into a specific position or POSTURE to facilitate examination, surgery, or for therapeutic purposes.Afferent Pathways: Nerve structures through which impulses are conducted from a peripheral part toward a nerve center.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)Neurons, Efferent: Neurons which send impulses peripherally to activate muscles or secretory cells.Nerve Tissue: Differentiated tissue of the central nervous system composed of NERVE CELLS, fibers, DENDRITES, and specialized supporting cells.Recovery of Function: A partial or complete return to the normal or proper physiologic activity of an organ or part following disease or trauma.Mandibular Nerve: A branch of the trigeminal (5th cranial) nerve. The mandibular nerve carries motor fibers to the muscles of mastication and sensory fibers to the teeth and gingivae, the face in the region of the mandible, and parts of the dura.Mechanoreceptors: Cells specialized to transduce mechanical stimuli and relay that information centrally in the nervous system. Mechanoreceptor cells include the INNER EAR hair cells, which mediate hearing and balance, and the various somatosensory receptors, often with non-neural accessory structures.Paresis: A general term referring to a mild to moderate degree of muscular weakness, occasionally used as a synonym for PARALYSIS (severe or complete loss of motor function). In the older literature, paresis often referred specifically to paretic neurosyphilis (see NEUROSYPHILIS). "General paresis" and "general paralysis" may still carry that connotation. Bilateral lower extremity paresis is referred to as PARAPARESIS.Cats: The domestic cat, Felis catus, of the carnivore family FELIDAE, comprising over 30 different breeds. The domestic cat is descended primarily from the wild cat of Africa and extreme southwestern Asia. Though probably present in towns in Palestine as long ago as 7000 years, actual domestication occurred in Egypt about 4000 years ago. (From Walker's Mammals of the World, 6th ed, p801)Sweating: The process of exocrine secretion of the SWEAT GLANDS, including the aqueous sweat from the ECCRINE GLANDS and the complex viscous fluids of the APOCRINE GLANDS.Physical Stimulation: Act of eliciting a response from a person or organism through physical contact.Blood Pressure: PRESSURE of the BLOOD on the ARTERIES and other BLOOD VESSELS.
Specific and innervation-regulated expression of the intermediate filament protein nestin at neuromuscular and myotendinous junctions in skeletal muscle. (1/476)
The intermediate filament proteins nestin, vimentin, and desmin show a specific temporal expression pattern during the development of myofibers from myogenic precursor cells. Nestin and vimentin are actively expressed during early developmental stages to be later down-regulated, vimentin completely and nestin to minimal levels, whereas desmin expression begins later and is maintained in mature myofibers, in which desmin participates in maintaining structural integrity. In this study we have analyzed the expression levels and distribution pattern of nestin in intact and denervated muscle in rat and in human. Nestin immunoreactivity was specifically and focally localized in the sarcoplasm underneath neuromuscular junctions (NMJs) and in the vicinity of the myotendinous junctions (MTJs), ie, in regions associated with acetylcholine receptors (AChRs). This association prompted us to analyze nestin in neurogenically and myogenically denervated muscle. Immunoblot analysis disclosed a marked overall increase of accumulated nestin protein. Similar to the extrajunctional redistribution of AChRs in denervated myofibers, nestin immunoreactivity extended widely beyond the NMJ region. Re-innervation caused complete reversion of these changes. Our study demonstrates that the expression levels and distribution pattern of nestin are regulated by innervation, ie, signal transduction into myofibers. (+info)Uninjured C-fiber nociceptors develop spontaneous activity and alpha-adrenergic sensitivity following L6 spinal nerve ligation in monkey. (2/476)
We investigated whether uninjured cutaneous C-fiber nociceptors in primates develop abnormal responses after partial denervation of the skin. Partial denervation was induced by tightly ligating spinal nerve L6 that innervates the dorsum of the foot. Using an in vitro skin-nerve preparation, we recorded from uninjured single afferent nerve fibers in the superficial peroneal nerve. Recordings were made from 32 C-fiber nociceptors 2-3 wk after ligation and from 29 C-fiber nociceptors in control animals. Phenylephrine, a selective alpha1-adrenergic agonist, and UK14304 (UK), a selective alpha2-adrenergic agonist, were applied to the receptive field for 5 min in increasing concentrations from 0.1 to 100 microM. Nociceptors from in vitro control experiments were not significantly different from nociceptors recorded by us previously in in vivo experiments. In comparison to in vitro control animals, the afferents found in lesioned animals had 1) a significantly higher incidence of spontaneous activity, 2) a significantly higher incidence of response to phenylephrine, and 3) a higher incidence of response to UK. In lesioned animals, the peak response to phenylephrine was significantly greater than to UK, and the mechanical threshold of phenylephrine-sensitive afferents was significantly lower than for phenylephrine-insensitive afferents. Staining with protein gene product 9.5 revealed an approximately 55% reduction in the number of unmyelinated terminals in the epidermis of the lesioned limb compared with the contralateral limb. Thus uninjured cutaneous C-fiber nociceptors that innervate skin partially denervated by ligation of a spinal nerve acquire two abnormal properties: spontaneous activity and alpha-adrenergic sensitivity. These abnormalities in nociceptor function may contribute to neuropathic pain. (+info)Arousal from sleep shortens sympathetic burst latency in humans. (3/476)
1. Bursts of sympathetic activity in muscle nerves are phase-locked to the cardiac cycle by the sinoaortic baroreflexes. Acoustic arousal from non-rapid eye movement (NREM) sleep reduces the normally invariant interval between the R-wave of the electrocardiogram (ECG) and the peak of the corresponding sympathetic burst; however, the effects of other forms of sleep disruption (i.e. spontaneous arousals and apnoea-induced arousals) on this temporal relationship are unknown. 2. We simultaneously recorded muscle sympathetic nerve activity in the peroneal nerve (intraneural electrodes) and the ECG (surface electrodes) in seven healthy humans and three patients with sleep apnoea syndrome during NREM sleep. 3. In seven subjects, burst latencies were shortened subsequent to spontaneous K complexes (1.297 +/- 0.024 s, mean +/- s. e.m.) and spontaneous arousals (1.268 +/- 0.044 s) compared with latencies during periods of stable NREM sleep (1.369 +/- 0.023 s). In six subjects who demonstrated spontaneous apnoeas during sleep, apnoea per se did not alter burst latency relative to sleep with stable electroencephalogram (EEG) and breathing (1.313 +/- 0.038 vs. 1.342 +/- 0.026 s); however, following apnoea-induced EEG perturbations, burst latencies were reduced (1.214 +/- 0.034 s). 4. Arousal-induced reduction in sympathetic burst latency may reflect a temporary diminution of baroreflex buffering of sympathetic outflow. If so, the magnitude of arterial pressure perturbations during sleep (e.g. those caused by sleep disordered breathing and periodic leg movements) may be augmented by arousal. (+info)Activity-dependent slowing of conduction differentiates functional subtypes of C fibres innervating human skin. (4/476)
1. The effects of impulse activity on conduction in cutaneous C fibres have been examined in 46 microneurographic recordings from 11 normal subjects and 11 diabetic patients with normal nerve conduction. A tungsten microelectrode was inserted into a cutaneous nerve, usually the superficial peroneal close to the ankle, and intraneural microstimulation was used to identify an area of skin innervated. Three minute trains of 0.25 ms stimuli at 1, 2 and 4 Hz were then delivered to the surface of the skin, separated by intervals of 6 min with stimulation at 0.25 Hz. Slowing and block of conduction were measured from the nerve responses for up to seven C units per stimulation sequence. 2. Three types of C unit were distinguished by their responses to repetitive stimulation: type 1 units slowed progressively during the 3 min trains; slowing of type 2 units reached a plateau within 1 min; while type 3 units hardly slowed at all. Data from normal and diabetic subjects did not differ and were pooled. After 3 min at 2 Hz, the percentage increases in latency were for type 1, 28.3 +/- 9.7 (n = 63 units, mean +/- s.d.); for type 2, 5.2 +/- 1.6 (n = 14); and for type 3, 0.8 +/- 0.5 (n = 5), with no overlap. After 3 min at 4 Hz, 58 % of type 1 units (but no type 2 or 3 units) blocked intermittently. Recovery of latency after stimulation was faster for type 2 than for type 1 units, but conduction velocities of the three types were similar. 3. Type 1 units were identified as nociceptors and 7 type 2 units were identified as 'cold' fibres, activated by non-noxious cold, with no overlap in modality. None of the units tested was activated by weak mechanical stimuli or reflex sympathetic activation. 4. Spike waveforms were averaged for 18 type 1, 10 type 2 and 6 type 3 units. All units had predominantly triphasic action potentials with a major negative peak, but those of type 3 units were on average both smaller and briefer than those of type 1 and type 2 units. 5. It is concluded that repetitive electrical stimulation reliably differentiates nociceptive from cold-specific C fibres innervating human hairy skin, as has previously been shown for the rat. Cold fibres can propagate impulses continuously at much higher rates than nociceptive fibres. The nature of the type 3 units is unclear. (+info)Respiratory and cardiac modulation of single sympathetic vasoconstrictor and sudomotor neurones to human skin. (5/476)
1. The firing of single sympathetic neurones was recorded via tungsten microelectrodes in cutaneous fascicles of the peroneal nerve in awake humans. Studies were made of 17 vasoconstrictor neurones during cold-induced cutaneous vasoconstriction and eight sudomotor neurones during heat-induced sweating. Oligounitary recordings were obtained from 8 cutaneous vasconstrictor and 10 sudomotor sites. Skin blood flow was measured by laser Doppler flowmetry, and sweating by changes in skin electrical resistance within the innervation territory on the dorsum of the foot. 2. Perispike time histograms revealed respiratory modulation in 11 (65 %) vasoconstrictor and 4 (50 %) sudomotor neurones. After correcting for estimated conduction delays, the firing probability was higher in inspiration for both classes of neurone. Measured from the oligounitary recordings, the respiratory modulation indices were 67. 7 +/- 3.9 % for vasoconstrictor and 73.5 +/- 5.7 % for sudomotor neurones (means +/- s.e.m.). As previously found for sudomotor neurones, cardiac rhythmicity was expressed by 7 (41 %) vasoconstrictor neurones, 5 of which showed no significant coupling to respiration. Measured from the oligounitary records, the cardiac modulation of cutaneous vasoconstrictor activity was 58.6 +/- 4.9 %, compared with 74.4 +/- 6.4 % for sudomotor activity. 3. Both vasoconstrictor and sudomotor neurones displayed low average firing rates (0.53 and 0.62 Hz, respectively). The percentage of cardiac intervals in which units fired was 38 % and 35 %, respectively. Moreover, when considering only those cardiac intervals when a unit fired, vasoconstrictor and sudomotor neurones generated a single spike 66 % and 67 % of the time. Rarely were more than four spikes generated by a single neurone. 4. We conclude that human cutaneous vasoconstrictor and sudomotor neurones share several properties: both classes contain subpopulations that are modulated by respiration and/or the cardiac cycle. The data suggest that the intensity of a multi-unit burst of vasoconstrictor or sudomotor impulses is probably governed primarily by firing incidence and the recruitment of additional neurones, rather than by an increase in the number of spikes each unit contributes to a burst. (+info)Responses of sympathetic outflow to skin during caloric stimulation in humans. (6/476)
We previously showed that caloric vestibular stimulation elicits increases in sympathetic outflow to muscle (MSNA) in humans. The present study was conducted to determine the effect of this stimulation on sympathetic outflow to skin (SSNA). The SSNA in the tibial and peroneal nerves and nystagmus was recorded in nine subjects when the external meatus was irrigated with 50 ml of cold (10 degrees C) or warm (44 degrees C) water. During nystagmus, the SSNA in tibial and peroneal nerves decreased to 50 +/- 4% (with baseline value set as 100%) and 61 +/- 4%, respectively. The degree of SSNA suppression in both nerves was proportional to the maximum slow-phase velocity of nystagmus. After nystagmus, the SSNA increased to 166 +/- 7 and 168 +/- 6%, respectively, and the degree of motion sickness symptoms was correlated with this SSNA increase. These results suggest that the SSNA response differs from the MSNA response during caloric vestibular stimulation and that the SSNA response elicited in the initial period of caloric vestibular stimulation is different from that observed during the period of motion sickness symptoms. (+info)Induction of neurally mediated syncope with adenosine. (7/476)
BACKGROUND: Tilt testing is used to establish the diagnosis of neurally mediated syncope. However, applicability of the tilt test is limited by test sensitivity and length of time required to perform the test. We hypothesized that adenosine could facilitate the induction of neurally mediated syncope through its sympathomimetic effects and therefore could be used as an alternative to routine tilt testing. METHODS AND RESULTS: In protocol 1, the yield of adenosine tilt testing (12 mg while upright, followed by 60 degrees tilt for 5 minutes) and a 15-minute isoproterenol tilt test were compared in 84 patients with a negative 30-minute drug-free tilt test. In protocol 2, 100 patients underwent an initial adenosine tilt test followed by our routine tilt test (30-minute drug-free tilt followed by a 15-minute isoproterenol tilt). Six additional control patients underwent microneurography of the peroneal nerve to compare the sympathomimetic effects during bolus administration of adenosine and continuous infusion of isoproterenol. In protocol 1, the yields of adenosine (8 of 84, 10%) and isoproterenol (7 of 84, 8%) tilt testing were comparable (P=NS). In protocol 2, the yields of adenosine (19 of 100, 19%) and routine (22 of 100, 22%) tilt testing were also comparable (P=NS). Although the yield of adenosine tilt testing was comparable in both protocols, patients with a negative adenosine tilt test but a positive routine tilt test usually required isoproterenol to elicit the positive response. Microneurography confirmed discordant sympathetic activation after adenosine and isoproterenol administration. CONCLUSIONS: Adenosine is effective for the induction of neurally mediated syncope, with a diagnostic yield comparable to routine tilt testing. However, the discordant results obtained with adenosine and the isoproterenol phase of routine tilt testing suggest that adenosine and isoproterenol tilt testing may have complementary roles in eliciting a positive response. Therefore, a tilt protocol that uses an initial adenosine tilt followed, if necessary, by an isoproterenol tilt would be expected to increase the overall yield and reduce the duration of tilt testing. (+info)Aberrant neurofilament phosphorylation in sensory neurons of rats with diabetic neuropathy. (8/476)
Aberrant neurofilament phosphorylation occurs in many neurodegenerative diseases, and in this study, two animal models of type 1 diabetes--the spontaneously diabetic BB rat and the streptozocin-induced diabetic rat--have been used to determine whether such a phenomenon is involved in the etiology of the symmetrical sensory polyneuropathy commonly associated with diabetes. There was a two- to threefold (P < 0.05) elevation of neurofilament phosphorylation in lumbar dorsal root ganglia (DRG) of diabetic rats that was localized to perikarya of medium to large neurons using immunocytochemistry. Additionally, diabetes enhanced neurofilament M phosphorylation by 2.5-fold (P < 0.001) in sural nerve of BB rats. Neurofilaments are substrates of the mitogen-activated protein kinase (MAPK) family, which includes c-jun NH2-terminal kinase (JNK) or stress-activated protein kinase (SAPK1) and extracellular signal-regulated kinases (ERKs) 1 and 2. Diabetes induced a significant three- to fourfold (P < 0.05) increase in phosphorylation of a 54-kDa isoform of JNK in DRG and sural nerve, and this correlated with elevated c-Jun and neurofilament phosphorylation. In diabetes, ERK phosphorylation was also increased in the DRG, but not in sural nerve. Immunocytochemistry showed that JNK was present in sensory neuron perikarya and axons. Motoneuron perikarya and peroneal nerve of diabetic rats showed no evidence of increased neurofilament phosphorylation and failed to exhibit phosphorylation of JNK. It is hypothesized that in sensory neurons of diabetic rats, aberrant phosphorylation of neurofilament may contribute to the distal sensory axonopathy observed in diabetes. (+info)- Surgical and anatomical landmarks for the perineal branch of the posterior femoral cutaneous nerve: implications in perineal pain syndromes. (medscape.com)
- Lesions to the plantaris tendon, the sural nerve or the posterior tibial artery were more common in group B, however, without reaching statistical significance. (vumc.nl)
- The sciatic nerve, which provides motor innervation to the muscles of the posterior thigh and sensory innervation to the lateral side of the lower leg and lateral side and sole of the foot, ends just above the posterior knee in the popliteal fossa and bifurcates into the common fibular and tibial nerves. (statpearls.com)
- The common fibular nerve continues distally into the anterior and lateral compartments of the leg and foot whereas the tibial nerve descends towards the posterior compartment. (statpearls.com)
- The tibial nerve arises in the popliteal fossa as the other branch of the sciatic nerve and supplies the motor innervation to the posterior deep flexor compartment of the lower leg. (statpearls.com)
- This anatomy makes the posterior aspect of the medial malleolus an excellent landmark for visualizing the tibial nerve on MR imaging where it is visible between the flexor digitorum longus and flexor hallucis longus muscle tendons. (statpearls.com)
- The medial plantar nerve travels a course lateral to the posterior tibial artery and anterior to the medial plantar artery. (statpearls.com)
- What is the pathogenesis of deep peroneal nerve entrapment? (medscape.com)
- Deep peroneal nerve entrapment is most commonly due to compression and repetitive mechanical irritation of the nerve at the ankle beneath the extensor retinaculum. (medscape.com)
- Entrapment of the deep peroneal nerve in this location has also been called the anterior tarsal tunnel syndrome. (medscape.com)
- Deep peroneal nerve entrapment, however, can occur anywhere along the nerve's course (eg, just distal to the neck of the fibula, anterior to the ankle joint, or distal to the inferior extensor retinaculum), though such entrapment is not considered anterior tarsal tunnel syndrome. (medscape.com)
- Common causes of proximal entrapment of the deep peroneal nerve include space-occupying lesions about the proximal fibula, surgical procedures about the lateral knee (eg, proximal tibial osteotomy), and chronic anterior exertional compartment syndrome seen in athletes. (medscape.com)
- Knee pain due to saphenous nerve entrapment. (medscape.com)
- Vieira RL, Rosenberg ZS, Kiprovski K. MRI of the distal biceps femoris muscle: normal anatomy, variants, and association with common peroneal entrapment neuropathy. (medscape.com)
- nerve also gives off a lateral sural cutaneous brach which joins with the the medial sural cutaneous nerve (from tibial nerve) to form the sural nerve. (wordpress.com)
- The foot receives its nerve supply from the superficial peroneal (fibular) nerve, deep fibular nerve, tibial nerve (and its branches), sural nerve, and saphenous nerve. (statpearls.com)
- In group A, the peroneal nerve segment from the contrala-teral limb was attached to the sural nerve. (medrazgl.si)
- Injured neurons were therefore present in the dorsal root ganglia from which axons of the sural nerve arise. (medrazgl.si)
- In group C, an end-to-side ana-stomosis of the peroneal nerve segment from the ipsilateral limb was made on the sural ner-ve. (medrazgl.si)
- The skin around the terminal in-nervation field of the sural nerve was therefore denervated. (medrazgl.si)
- Drop foot is typically caused by neurologic disease such as lumbar disc herniation, but we report two rare cases of deep peroneal nerve palsy with isolated lateral compartment syndrome secondary to peroneus longus tears. (springeropen.com)
- The characteristic anatomical situation between the fibular tunnel and peroneus longus might have caused deep peroneal nerve palsy in these two cases after hematoma adjacent to the fibular tunnel increased lateral compartment pressure. (springeropen.com)
- To the best of our knowledge, deep peroneal nerve palsy with lateral compartment syndrome secondary to complete avulsion of the proximal origin of the peroneus longus has not been reported. (springeropen.com)
- Two rare cases of deep peroneal nerve palsy with isolated lateral compartment syndrome secondary to peroneus longus tear are reported herein. (springeropen.com)
- Further, it passes along the lateral surface of the extensor digitorum longus, at the middle of the lower leg penetrates the crural fascia and then divides into two terminal branches: the medial dorsal cutaneous nerve and the intermediate dorsal cutaneous nerve that form seven dorsal digital nerves . (anatomynext.com)
- With its muscular branches the superficial peroneal nerve innervates the peroneus longus and peroneus brevis. (anatomynext.com)
- The ankle's motor nerves are primarily served by the sciatic nerves, which are branches of the lumbar nerves and are the largest and longest nerves in the body. (innerbody.com)
- Both nerves contribute significant terminal branches that will eventually supply the foot. (statpearls.com)
- As it arises in the foot and travels more inferiorly, the superficial fibular nerve further divides into two branches: medial and intermediate dorsal cutaneous nerves, which may be subject to anatomic variation. (statpearls.com)
- From there, the medial plantar nerve continues to divide into muscular and cutaneous branches, ultimately contributing to the motor innervation to the abductor hallucis, flexor digitorum brevis, flexor hallucis brevis, and first lumbrical muscles and the sensory innervation to the medial side of the sole (i.e. first three digits and the medial half of the fourth digit). (statpearls.com)
- This nerve also provides sensory innervation to the skin of the dorsum of the foot, except the space between the first and second toe and the lateral side of the fifth toe. (anatomynext.com)
- Compression of the peroneal nerve at the fibular head usually manifests as "foot drop. (biomedcentral.com)
- Repeated dorsiflexion and plantarflexion of the ankle contributes to this mechanical condition by pinching the nerve in this tight space, and inversion trauma has been shown to lower the motor conduction velocity of the deep peroneal nerve. (medscape.com)
- The superficial fibular nerve supplies the motor innervation to the lateral compartment of the leg, which is responsible for foot eversion, while the deep fibular nerve supplies the motor innervation to the anterior compartment, responsible for ankle dorsiflexion, toe extension, and foot inversion. (statpearls.com)
- Within the lateral compartment, the superficial fibular nerve courses within the peroneus longus muscle and emerges through the anterolateral aspect of the musculature about 12 cm above the ankle joint at the level of a defect in the deep (crural) fascia. (statpearls.com)
- At approximately 1.3 cm above the ankle joint, the nerve divides into a lateral branch and a medial branch. (statpearls.com)
- The region where the extensor hallucis brevis tendon crosses over the medial branch also serves as an excellent landmark for identification of the deep fibular nerve in the foot. (statpearls.com)
- Carai A, Fenu G, Sechi E, Crotti FM, Montella A. Anatomical variability of the lateral femoral cutaneous nerve: findings from a surgical series. (medscape.com)
- These nerves come from peripheral nerves that arise from the L4 to S3 nerve roots and contribute to the somatic motor function, general sensory information, and the cutaneous sensation of the foot. (statpearls.com)
- In group B, the same procedure was used as in group A. In addition, dorso-cutaneous nerves from the L4-L6 spinal segments were cut. (medrazgl.si)
- Neurosurgeon - specializes in treating diseases and conditions that affect the nervous system including the spine, spinal cord, brain and the peripheral nerves. (nerve-injury.com)
- nervus peroneus superficialis ) is one of the terminal branch of the common peroneal nerve. (anatomynext.com)
- Common peroneal nerves of both right and left legs are exposed to strenuous and chronic stress exerted by vibration and paddling of mechanical sewing machine. (biomedcentral.com)
- Standard Nerve Conduction Techniques using constant measured distances were applied to evaluate common peroneal nerve (motor) in both legs of each individual. (biomedcentral.com)
- Operating mechanical sewing machine by paddling chronically and arduously could have attributed to abnormal nerve conduction study parameters due to vibration effect of the machine on right and left common peroneal nerves. (biomedcentral.com)
- The common peroneal nerve is superficial as it courses around the fibular neck. (biomedcentral.com)
- The common peroneal nerve pierced the deep fascia and lay over the fibular neck, which formed the floor of a short tunnel (the so-called fibular tunnel), then passed the lateral compartment just behind the peroneus longus. (springeropen.com)
- They descend into the buttock and into the thighs, where they divide into the tibial and common peroneal nerves. (innerbody.com)
- The common fibular nerve bifurcates into the superficial and deep fibular nerves. (statpearls.com)
- The superficial peroneal nerve pierces the peroneus longus muscle, then goes between it and the peroneus brevis. (anatomynext.com)
- Results: The rate of injury to the superficial peroneal nerve (SPN) was reduced from 25 to 3.6%, in group A compared with B (p = 0.033). (vumc.nl)
- What Type of Doctor Do You Need for a Peroneal Nerve Injury? (nerve-injury.com)
- A peroneal nerve injury can be extremely serious and can cause life long debilitation. (nerve-injury.com)
- What causes Peroneal Nerve Injury? (nerve-injury.com)
- Those who suffer from disorders that affect the nerves like Charcot-Marie-Tooth disease are also more likely to get a peroneal nerve injury. (nerve-injury.com)
- When diagnosing a peroneal nerve injury your doctor will typically perform two kinds of tests. (nerve-injury.com)
- There are a number of nerve activity tests that can also be carried out in order to diagnose a peroneal nerve injury. (nerve-injury.com)
- The kind of doctor needed to treat a peroneal nerve injury can be dependent on how the injury itself was obtained along with the severity of the symptoms. (nerve-injury.com)
- If you suspect you have a peroneal nerve injury see a general physician first, they will then refer you to a relevant specialist to help treat your individual case. (nerve-injury.com)
- Somatic nerve conduction studies (NCS), which specifically measure the conduction velocity, latency and amplitude of the neurological response following electrical stimulation of peripheral nerve, was applied to assess neural functions. (biomedcentral.com)
- The anterior tarsal tunnel contains four tendons, one artery, one vein, and the deep peroneal nerve. (medscape.com)
- Proximal to the tip of the medial malleolus, the tibial nerve bifurcates into the medial and lateral plantar nerves at the level of the tarsal tunnel with some variation. (statpearls.com)
- The clinical importance of variations in the surgical anatomy of the superficial peroneal nerve in the mid-third of the lateral leg. (medscape.com)
- These include having the activity in the muscles tested (Electromyography), testing how quickly electric signals can pass through your nerves (Nerve Conduction Tests) and an MRI. (nerve-injury.com)
- What Are the Symptoms of Peroneal Nerve Damage? (nerve-injury.com)
- There are a number of symptoms that are associated with peroneal nerve damage, these include weakness in the ankles or feet, toes dragging whilst walking, being unable to hold feet up and a decreased sensation (feeling numb or tingling) in upper or lower leg as well as the top of the foot. (nerve-injury.com)
- Objectives: To investigate the feasibility of inhibiting the stretch reflex of the soleus muscle by a conditioning stimulus applied to the deep peroneal nerve in spastic stroke participants during the early swing phase of gait. (utwente.nl)
- Materials and Methods: This study investigated the effect of an electrical conditioning stimulus applied to the deep peroneal nerve on the magnitude at the peak of the soleus stretch reflex in the early swing phase of gait in six spastic stroke participants. (utwente.nl)
- The deep peroneal, located as the name suggests, at a deeper level of the leg, supplies nerves to the superficial peroneal nerve. (nerve-injury.com)
- The patients were able to return their original sports after 3 months, and clinical examination revealed no hypesthesia or muscle weakness in the deep peroneal nerve area at the time of last follow-up. (springeropen.com)
- There was decreased sensation in the deep peroneal nerve area, but sensation was normal in the superficial peroneal nerve area. (springeropen.com)
- Conclusions: It is concluded that the inhibition of the soleus stretch reflex with an electrical conditioning stimulus applied to the deep peroneal nerve is feasible in the early swing phase of walking. (utwente.nl)
- The deep fibular nerve descends lateral to the anterior tibial artery and is located just anterior to the interosseous membrane within the anterior compartment of the leg. (statpearls.com)
- It is important to note that although the deep fibular nerve usually courses laterally to the anterior tibial artery, some anatomical variations exist. (statpearls.com)
- Regardless of variation, the anterior tibial artery makes an excellent landmark for identifying the deep fibular nerve in the leg on MR imaging. (statpearls.com)
- The majority of peroneal nerve injuries are caused by trauma or come as a result of medical treatment. (nerve-injury.com)
- Physiatrist - specializes in non-surgical care from nerve, muscle and bone injuries and disorders that impair normal everyday function. (nerve-injury.com)
- Damage to the peroneal nerve can result in minor loss of mobility or, in more extreme cases can result in permanent disability. (nerve-injury.com)
- There are a number of factors that can cause damage to the peroneal nerve and it can be something that will develop over time. (nerve-injury.com)
- Continuous crossing of the legs compresses the peroneal nerve which can lead to damage over time. (nerve-injury.com)
- Peroneal nerve damage is more commonly seen in those who are extremely underweight or suffering with anorexia , those who are suffering with certain autoimmune diseases or conditions or those who have nerve damage related to other medical issues like diabetes. (nerve-injury.com)
- Foot drop is where the foot can can not function the same way it used to due to weakness or damage of the peroneal nerve or the fibular nerve. (nerve-injury.com)
- Neurologist - specializes in the treatment of the nervous system and works with patients suffering from nerve damage. (nerve-injury.com)
- Nerve conduction study (NCS) helps in delineating the extent and distribution of neural lesions. (biomedcentral.com)