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Sample records for abnormal nerve conduction

  1. Nerve conduction

    MedlinePlus

    ... fascicles) that contain hundreds of individual nerve fibers (neurons). Neurons consist of dendrites, axon, and cell body. The ... tree-like structures that receive signals from other neurons and from special sensory cells that sense the ...

  2. Nerve conduction velocity

    MedlinePlus

    ... to measure the speed of the nerve signals. Electromyography (recording from needles placed into the muscles) is ... Often, the nerve conduction test is followed by electromyography (EMG). In this test, needles are placed into ...

  3. Evolution of rapid nerve conduction.

    PubMed

    Castelfranco, Ann M; Hartline, Daniel K

    2016-06-15

    Rapid conduction of nerve impulses is a priority for organisms needing to react quickly to events in their environment. While myelin may be viewed as the crowning innovation bringing about rapid conduction, the evolution of rapid communication mechanisms, including those refined and enhanced in the evolution of myelin, has much deeper roots. In this review, a sequence is traced starting with diffusional communication, followed by transport-facilitated communication, the rise of electrical signaling modalities, the invention of voltage-gated channels and "all-or-none" impulses, the emergence of elongate nerve axons specialized for communication and their fine-tuning to enhance impulse conduction speeds. Finally within the evolution of myelin itself, several innovations have arisen and have been interactively refined for speed enhancement, including the addition and sealing of layers, their limitation by space availability, and the optimization of key parameters: channel density, lengths of exposed nodes and lengths of internodes. We finish by suggesting several design principles that appear to govern the evolution of rapid conduction. This article is part of a Special Issue entitled SI: Myelin Evolution.

  4. Disruption of myelin leads to ectopic expression of K(V)1.1 channels with abnormal conductivity of optic nerve axons in a cuprizone-induced model of demyelination.

    PubMed

    Bagchi, Bandita; Al-Sabi, Ahmed; Kaza, Seshu; Scholz, Dimitri; O'Leary, Valerie B; Dolly, J Oliver; Ovsepian, Saak V

    2014-01-01

    The molecular determinants of abnormal propagation of action potentials along axons and ectopic conductance in demyelinating diseases of the central nervous system, like multiple sclerosis (MS), are poorly defined. Widespread interruption of myelin occurs in several mouse models of demyelination, rendering them useful for research. Herein, considerable myelin loss is shown in the optic nerves of cuprizone-treated demyelinating mice. Immuno-fluorescence confocal analysis of the expression and distribution of voltage-activated K⁺ channels (K(V)1.1 and 1.2 α subunits) revealed their spread from typical juxta-paranodal (JXP) sites to nodes in demyelinated axons, albeit with a disproportionate increase in the level of K(V)1.1 subunit. Functionally, in contrast to monophasic compound action potentials (CAPs) recorded in controls, responses derived from optic nerves of cuprizone-treated mice displayed initial synchronous waveform followed by a dispersed component. Partial restoration of CAPs by broad spectrum (4-aminopyridine) or K(V)1.1-subunit selective (dendrotoxin K) blockers of K⁺ currents suggest enhanced K(V)1.1-mediated conductance in the demyelinated optic nerve. Biophysical profiling of K⁺ currents mediated by recombinant channels comprised of different K(V)1.1 and 1.2 stoichiometries revealed that the enrichment of K(V)1 channels K(V)1.1 subunit endows a decrease in the voltage threshold and accelerates the activation kinetics. Together with the morphometric data, these findings provide important clues to a molecular basis for temporal dispersion of CAPs and reduced excitability of demyelinated optic nerves, which could be of potential relevance to the patho-physiology of MS and related disorders.

  5. Median Nerve Conduction in Healthy Nigerians: Normative Data

    PubMed Central

    Owolabi, LF; Adebisi, SS; Danborno, BS; Buraimoh, AA

    2016-01-01

    Background: Because of lack of local normative data, electrodiagnostic laboratories in Nigeria apply standard values generated in the USA and Europe to diagnose different median nerve abnormalities. Aim: To develop normative values for motor and sensory median nerve conduction studies (NCSs) in Nigerian population. Subjects and Methods: In a cross-sectional study design, a total of 200 healthy volunteers were selected after clinical evaluation to exclude systemic or neuromuscular disorders. NCS of the median nerves was conducted on all the healthy volunteers according to a standardized protocol. The data included in the final analysis were amplitude, latency, and nerve conduction velocity. Ethical approval was obtained for the study. Results: The reference range for median nerve (motor) velocity, distal latency, and amplitude were 49.48–66.92, 1.95–4.52, and 4.3–11.3, respectively. The reference range for median nerve F-wave latency was 44.8–70.5. The reference range for median nerve (sensory) velocity, distal latency, and amplitude were 44.8–70.5, 1.98–4.52, and 16.6–58.4, respectively. Conclusion: Reference values for the nerve conduction parameters of the median (motor and sensory) in the study population were similar to those obtained in the literature. PMID:27213090

  6. Conduction Properties Of Decellularized Nerve Biomaterials.

    PubMed

    Urbanchek, M G; Shim, B S; Baghmanli, Z; Wei, B; Schroeder, K; Langhals, N B; Miriani, R M; Egeland, B M; Kipke, D R; Martin, D C; Cederna, P S

    2010-04-30

    The purpose of this study is to optimize poly(3,4,-ethylenedioxythiophene) (PEDOT) polymerization into decellular nerve scaffolding for interfacing to peripheral nerves. Our ultimate aim is to permanently implant highly conductive peripheral nerve interfaces between amputee, stump, nerve fascicles and prosthetic electronics. Decellular nerve (DN) scaffolds are an FDA approved biomaterial (Axogen ) with the flexible tensile properties needed for successful permanent coaptation to peripheral nerves. Biocompatible, electroconductive, PEDOT facilitates electrical conduction through PEDOT coated acellular muscle. New electrochemical methods were used to polymerize various PEDOT concentrations into DN scaffolds without the need for a final dehydration step. DN scaffolds were then tested for electrical impedance and charge density. PEDOT coated DN scaffold materials were also implanted as 15-20mm peripheral nerve grafts. Measurement of in-situ nerve conduction immediately followed grafting. DN showed significant improvements in impedance for dehydrated and hydrated, DN, polymerized with moderate and low PEDOT concentrations when they were compared with DN alone (a ≤ 0.05). These measurements were equivalent to those for DN with maximal PEDOT concentrations. In-situ, nerve conduction measurements demonstrated that DN alone is a poor electro-conductor while the addition of PEDOT allows DN scaffold grafts to compare favorably with the "gold standard", autograft (Table 1). Surgical handling characteristics for conductive hydrated PEDOT DN scaffolds were rated 3 (pliable) while the dehydrated models were rated 1 (very stiff) when compared with autograft ratings of 4 (normal). Low concentrations of PEDOT on DN scaffolds provided significant increases in electro active properties which were comparable to the densest PEDOT coatings. DN pliability was closely maintained by continued hydration during PEDOT electrochemical polymerization without compromising electroconductivity.

  7. Conduction Properties Of Decellularized Nerve Biomaterials

    PubMed Central

    Urbanchek, M.G.; Shim, B.S.; Baghmanli, Z.; Wei, B.; Schroeder, K.; Langhals, N.B.; Miriani, R.M.; Egeland, B.M.; Kipke, D.R.; Martin, D.C.; Cederna, P.S.

    2011-01-01

    The purpose of this study is to optimize poly(3,4,-ethylenedioxythiophene) (PEDOT) polymerization into decellular nerve scaffolding for interfacing to peripheral nerves. Our ultimate aim is to permanently implant highly conductive peripheral nerve interfaces between amputee, stump, nerve fascicles and prosthetic electronics. Decellular nerve (DN) scaffolds are an FDA approved biomaterial (Axogen ) with the flexible tensile properties needed for successful permanent coaptation to peripheral nerves. Biocompatible, electroconductive, PEDOT facilitates electrical conduction through PEDOT coated acellular muscle. New electrochemical methods were used to polymerize various PEDOT concentrations into DN scaffolds without the need for a final dehydration step. DN scaffolds were then tested for electrical impedance and charge density. PEDOT coated DN scaffold materials were also implanted as 15–20mm peripheral nerve grafts. Measurement of in-situ nerve conduction immediately followed grafting. DN showed significant improvements in impedance for dehydrated and hydrated, DN, polymerized with moderate and low PEDOT concentrations when they were compared with DN alone (a ≤ 0.05). These measurements were equivalent to those for DN with maximal PEDOT concentrations. In-situ, nerve conduction measurements demonstrated that DN alone is a poor electro-conductor while the addition of PEDOT allows DN scaffold grafts to compare favorably with the “gold standard”, autograft (Table 1). Surgical handling characteristics for conductive hydrated PEDOT DN scaffolds were rated 3 (pliable) while the dehydrated models were rated 1 (very stiff) when compared with autograft ratings of 4 (normal). Low concentrations of PEDOT on DN scaffolds provided significant increases in electro active properties which were comparable to the densest PEDOT coatings. DN pliability was closely maintained by continued hydration during PEDOT electrochemical polymerization without compromising

  8. Occupational exposure to pesticides and nerve conduction studies among Korean farmers.

    PubMed

    Park, Su Kyeong; Kong, Kyoung Ae; Cha, Eun Shil; Lee, Young Joo; Lee, Gyu Taek; Lee, Won Jin

    2012-01-01

    This study aimed to determine whether occupational exposure to pesticides was associated with decreased nerve conduction studies among farmers. On 2 separate occasions, the authors performed a cross-sectional study of a group of 31 male farmers who periodically applied pesticides. The study included questionnaire interviews and nerve conduction studies on the median, ulnar, posterior tibial, peroneal, and sural nerves. Although all mean values remained within laboratory normal limits, significant differences between the first and second tests were found in sensory conduction velocities on the median and sural nerves, and motor conduction velocities on the posterior tibial nerve. Lifetime days of pesticide application was negatively associated with nerve conduction velocities at most nerves after adjusting for potential confounders. These findings may reflect a link between occupational pesticide exposure and peripheral neurophysiologic abnormality that deserves further evaluation.

  9. Electrochemical Skin Conductance Correlates with Skin Nerve Fiber Density

    PubMed Central

    Novak, Peter

    2016-01-01

    Purpose: Electrochemical skin conductance (ESC) using reverse iontophoresis and chronoamperometry has been used to evaluate abnormal function of small fibers. How ESC correlates with loss of small fibers in skin is unclear. Methods: This was a prospective, blinded study. The primary outcome measure was the correlation between ESC at the feet and results of skin biopsies including epidermal nerve fiber density (ENFD) and sweat gland nerve fiber density (SGNFD) at the distal leg. ESC, ENFD, and SGNFD data were normalized by adjusting for weight. The secondary outcome measures were the correlation between ESC and the following variables: quantitative sudomotor axon reflex test (QSART) and symptom scales (neuropathy, pain and autonomic). Results: Eighty-one patients (mean ± sd): age = 53.3 ± 17.3, men/women = 25/56 were enrolled in the study. ESC was reduced in subjects with abnormally low ENFD (ENFD normal/abnormal, ESC = 1.17 ± 0.27/0.87 ± 0.34 μSiemens/kg, p < 0.0008) and abnormally low SGNFD (SGNFD normal/abnormal ESC = 1.09 ± 0.34/0.78 ± 0.3 μSiemens/kg, p < 0.0003). ESC correlated with ENFD (ρ = 0.73, p = 0.0001) and SGNFD (ρ = 0.64, p = 0.0001). ESC did not correlate with symptom scales. Conclusion: ESC is diminished in subjects who have a reduced number of small fibers in the skin and the ESC reduction is proportional to ENFD and SGNFD. ESC can be useful in detecting loss of small nerve fibers. PMID:27605912

  10. Electrochemical Skin Conductance Correlates with Skin Nerve Fiber Density

    PubMed Central

    Novak, Peter

    2016-01-01

    Purpose: Electrochemical skin conductance (ESC) using reverse iontophoresis and chronoamperometry has been used to evaluate abnormal function of small fibers. How ESC correlates with loss of small fibers in skin is unclear. Methods: This was a prospective, blinded study. The primary outcome measure was the correlation between ESC at the feet and results of skin biopsies including epidermal nerve fiber density (ENFD) and sweat gland nerve fiber density (SGNFD) at the distal leg. ESC, ENFD, and SGNFD data were normalized by adjusting for weight. The secondary outcome measures were the correlation between ESC and the following variables: quantitative sudomotor axon reflex test (QSART) and symptom scales (neuropathy, pain and autonomic). Results: Eighty-one patients (mean ± sd): age = 53.3 ± 17.3, men/women = 25/56 were enrolled in the study. ESC was reduced in subjects with abnormally low ENFD (ENFD normal/abnormal, ESC = 1.17 ± 0.27/0.87 ± 0.34 μSiemens/kg, p < 0.0008) and abnormally low SGNFD (SGNFD normal/abnormal ESC = 1.09 ± 0.34/0.78 ± 0.3 μSiemens/kg, p < 0.0003). ESC correlated with ENFD (ρ = 0.73, p = 0.0001) and SGNFD (ρ = 0.64, p = 0.0001). ESC did not correlate with symptom scales. Conclusion: ESC is diminished in subjects who have a reduced number of small fibers in the skin and the ESC reduction is proportional to ENFD and SGNFD. ESC can be useful in detecting loss of small nerve fibers.

  11. Motor nerve conduction velocity (MCV) and lead content in sciatic nerve of lead-exposed rats

    SciTech Connect

    Maehara, N.; Uchino, E.; Terayama, K.; Ohno, H.; Yamamura, K.

    1986-07-01

    There have been many pathological and electrophysiological studies of peripheral nerves in inorganic lead intoxication. Peripheral nerve conduction velocity (NCV) has been used as an objective measure of the effects of lead on the peripheral nerve function and has been examined with blood lead content. There have been few reports on the changes in NCV related to lead content in the peripheral nerve tissue under lead poisoning. In the present study, the authors have examined motor nerve conduction velocity (MCV) of the tail by a non-invasive method and lead content of the peripheral nerve in lead-exposed rats. Furthermore, they have attempted to assess the relationship between these two parameters.

  12. 21 CFR 882.1550 - Nerve conduction velocity measurement device.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Nerve conduction velocity measurement device. 882.1550 Section 882.1550 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... conduction velocity measurement device. (a) Identification. A nerve conduction velocity measurement device...

  13. 21 CFR 882.1550 - Nerve conduction velocity measurement device.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Nerve conduction velocity measurement device. 882.1550 Section 882.1550 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... conduction velocity measurement device. (a) Identification. A nerve conduction velocity measurement device...

  14. 21 CFR 882.1550 - Nerve conduction velocity measurement device.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Nerve conduction velocity measurement device. 882.1550 Section 882.1550 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... conduction velocity measurement device. (a) Identification. A nerve conduction velocity measurement device...

  15. 21 CFR 882.1550 - Nerve conduction velocity measurement device.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Nerve conduction velocity measurement device. 882.1550 Section 882.1550 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... conduction velocity measurement device. (a) Identification. A nerve conduction velocity measurement device...

  16. 21 CFR 882.1550 - Nerve conduction velocity measurement device.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Nerve conduction velocity measurement device. 882.1550 Section 882.1550 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... conduction velocity measurement device. (a) Identification. A nerve conduction velocity measurement device...

  17. Comparison of Nerve Excitability Testing, Nerve Conduction Velocity, and Behavioral Observations for Acrylamide Induced Peripheral Neuropathy

    EPA Science Inventory

    Nerve excitability (NE) testing is a sensitive method to test for peripheral neurotoxicity in humans,and may be more sensitive than compound nerve action potential (CNAP) or nerve conduction velocity (NCV).We used acrylamide to compare the NE and CNAP/NCV methods. Behavioral test...

  18. Three-dimensional conductive constructs for nerve regeneration.

    PubMed

    George, Paul M; Saigal, Rajiv; Lawlor, Michael W; Moore, Michael J; LaVan, David A; Marini, Robert P; Selig, Martin; Makhni, Melvin; Burdick, Jason A; Langer, Robert; Kohane, Daniel S

    2009-11-01

    The unique electrochemical properties of conductive polymers can be utilized to form stand-alone polymeric tubes and arrays of tubes that are suitable for guides to promote peripheral nerve regeneration. Noncomposite, polypyrrole (PPy) tubes ranging in inner diameter from 25 microm to 1.6 mm as well as multichannel tubes were fabricated by electrodeposition. While oxidation of the pyrrole monomer causes growth of the film, brief subsequent reduction allowed mechanical dissociation from the electrode mold, creating a stand-alone, conductive PPy tube. Conductive polymer nerve guides made in this manner were placed in transected rat sciatic nerves and shown to support nerve regeneration over an 8-week time period.

  19. Evaluation of Nerve Conduction Studies in Obese Children With Insulin Resistance or Impaired Glucose Tolerance.

    PubMed

    Ince, Hülya; Taşdemir, Haydar Ali; Aydin, Murat; Ozyürek, Hamit; Tilki, Hacer Erdem

    2015-07-01

    The aim of the study was to investigate nerve conduction studies in terms of neuropathic characteristics in obese patients who were in prediabetes stage and also to determine the abnormal findings. The study included 69 obese adolescent patients between April 2009 and December 2010. All patients and control group underwent motor (median, ulnar, tibial, and peroneal) and sensory (median, ulnar, sural, and medial plantar) nerve conduction studies and sympathetic skin response test. Sensory response amplitude of the medial plantar nerve was significantly lower in the patients with impaired glucose tolerance and insulin resistance. To our knowledge, the present study is the first study demonstrating the development of sensory and autonomic neuropathy due to metabolic complications of obesity in adolescent children even in the period without development of diabetes mellitus. We recommend that routine electrophysiological examinations be performed, using medial plantar nerve conduction studies and sympathetic skin response test. PMID:25342307

  20. Evaluation of Nerve Conduction Studies in Obese Children With Insulin Resistance or Impaired Glucose Tolerance.

    PubMed

    Ince, Hülya; Taşdemir, Haydar Ali; Aydin, Murat; Ozyürek, Hamit; Tilki, Hacer Erdem

    2015-07-01

    The aim of the study was to investigate nerve conduction studies in terms of neuropathic characteristics in obese patients who were in prediabetes stage and also to determine the abnormal findings. The study included 69 obese adolescent patients between April 2009 and December 2010. All patients and control group underwent motor (median, ulnar, tibial, and peroneal) and sensory (median, ulnar, sural, and medial plantar) nerve conduction studies and sympathetic skin response test. Sensory response amplitude of the medial plantar nerve was significantly lower in the patients with impaired glucose tolerance and insulin resistance. To our knowledge, the present study is the first study demonstrating the development of sensory and autonomic neuropathy due to metabolic complications of obesity in adolescent children even in the period without development of diabetes mellitus. We recommend that routine electrophysiological examinations be performed, using medial plantar nerve conduction studies and sympathetic skin response test.

  1. Somatosensory evoked potentials (SSEPs); sensory nerve conduction velocity (SNCV) and motor nerve conduction velocity (MNCV) in chronic renal failure.

    PubMed

    Makkar, R K; Kochar, D K

    1994-01-01

    Somatosensory evoked potentials, sensory and motor nerve conduction velocity were studied in 25 patients of chronic renal failure and the results were compared with 15 healthy persons. The values more than +/- 3 S.D. were considered abnormal. SNCV was reduced in 11/25 patients; average reduction being 18 m/s (highly significant, p < 0.001); MNCV was reduced in 11/25 patients, average reduction being 20 m/s (highly significant, p < 0.001). Both SNCV and MNCV in same person were reduced in 6/25 patients. In SSEP N9, N13 and N20 were delayed in almost all the patients (highly significant, p < 0.001). Amplitude of N20 and N13 were reduced in 1 and 4 patients respectively but amplitude of N9 was normal. Out of different IPLS, Ebw-N9 was delayed in 5/25 patients (p < 0.9, insignificant); N9-N13 was delayed in 8/25 patients (p < 0.001, highly significant); N13-N20 was delayed in 1/25 patients (p < 0.01, significant). The evidence of these neurophysiological abnormalities collectively suggest the presence of central-peripheral axonopathy in this disease. PMID:7956880

  2. Conductive PPY/PDLLA conduit for peripheral nerve regeneration

    PubMed Central

    Xu, Haixing; Holzwarth, Jeremy M.; Yan, Yuhua; Xu, Peihu; Zheng, Hua; Yin, Yixia; Li, Shipu; Ma, Peter X.

    2013-01-01

    The significant drawbacks and lack of success associated with current methods to treat critically sized nerve defects have led to increased interest in neural tissue engineering. Conducting polymers show great promise due to their electrical properties, and in the case of polypyrrole (PPY), its cell compatibility as well. Thus, the goal of this study is to synthesize a conducting composite nerve conduit with PPY and poly(D, L-lactic acid) (PDLLA), assess its ability to support the differentiation of rat pheochromocytoma 12 (PC12) cells in vitro, and determine its ability to promote nerve regeneration in vivo. Different amounts of PPY (5%, 10%, and 15%) are used to synthesize the conduits resulting in different conductivities (5.65, 10.40, and 15.56 ms/cm, respectively). When PC12 cells are seeded on these conduits and stimulated with 100 mV for 2 h, there is a marked increase in both the percentage of neurite-bearing cells and the median neurite length as the content of PPY increased. More importantly, when the PPY/PDLLA nerve conduit was used to repair a rat sciatic nerve defect it performed similarly to the gold standard autologous graft. These promising results illustrate the potential that this PPY/PDLLA conducting composite conduit has for neural tissue engineering. PMID:24138830

  3. Motor and sensory nerve conduction velocities in Yucatan minipigs.

    PubMed

    Hort-Legrand, C; Noah, L; Mériguet, E; Mésangeau, D

    2006-01-01

    Motor and/or sensory conduction velocities are used to assess peripheral nervous system disorders. Although the miniature pig represents a model of choice for long-term pharmacological experimentation, no study has so far been reported on this model in relation to the measurement of nerve conduction velocities. We developed the present technique and applied it to 34 3-18-month-old Yucatan minipigs. Motor and sensory conduction velocities were measured using the anterior tibial nerve and the internal plantar nerve, a branch of the posterior tibial nerve, respectively. The nerve conduction velocity data of motor (MNCV) and sensory (SNCV) nerves, together with the amplitude of the sensory nerve signal, were logarithmically dependent on the age of the tested animals (r(2)=0.92, 0.81 and 0.76, respectively). The mean values of MNCV and SNCV were 70.9 +/- 1.1 and 67.9 +/- 0.2 m/s, respectively, at the age of 16 months for these miniature pigs. In order to validate this model, we compared it with other known models when the velocities reached a plateau at the end of the study. These values were found to be higher than those in humans or rats, but are comparable to those of the baboon, one of the best large animal models for human pathologies. Because the physiology and metabolism of the minipig resemble those of humans, and due to its long lifetime, this animal represents a good model for studying the development of neuropathology.

  4. Insulin Pump Therapy Is Associated with Lower Rates of Retinopathy and Peripheral Nerve Abnormality

    PubMed Central

    Zabeen, Bedowra; Craig, Maria E.; Virk, Sohaib A.; Pryke, Alison; Chan, Albert K. F.; Cho, Yoon Hi; Benitez-Aguirre, Paul Z.; Hing, Stephen; Donaghue, Kim C.

    2016-01-01

    Objective To compare rates of microvascular complications in adolescents with type 1 diabetes treated with continuous subcutaneous insulin infusion (CSII) versus multiple daily injections (MDI). Research Design and Methods Prospective cohort of 989 patients (aged 12–20 years; diabetes duration >5 years) treated with CSII or MDI for >12 months. Microvascular complications were assessed from 2000–14: early retinopathy (seven-field fundal photography), peripheral nerve function (thermal and vibration threshold testing), autonomic nerve abnormality (heart rate variability analysis of electrocardiogram recordings) and albuminuria (albumin creatinine ratio/timed overnight albumin excretion). Generalized estimating equations (GEE) were used to examine the relationship between treatment and complications rates, adjusting for socio-economic status (SES) and known risk factors including HbA1c and diabetes duration. Results Comparing CSII with MDI: HbA1C was 8.6% [70mmol/mol] vs. 8.7% [72 mmol/mol]) (p = 0.7), retinopathy 17% vs. 22% (p = 0.06); microalbuminuria 1% vs. 4% (p = 0.07), peripheral nerve abnormality 27% vs. 33% (p = 0.108) and autonomic nerve abnormality 24% vs. 28% (p = 0.401). In multivariable GEE, CSII use was associated with lower rates of retinopathy (OR 0.66, 95% CI 0.45–0.95, p = 0.029) and peripheral nerve abnormality (OR 0.63, 95% CI 0.42–0.95, p = 0.026), but not albuminuria (OR 0.46, 95% CI 0.10–2.17, p = 0.33). SES was not associated with any of the complication outcomes. Conclusions In adolescents, CSII use is associated with lower rates of retinopathy and peripheral nerve abnormality, suggesting an apparent benefit of CSII over MDI independent of glycemic control or SES. PMID:27050468

  5. Central motor conduction time by magnetic stimulation of the cortex and peripheral nerve conduction follow-up studies in Friedreich's ataxia.

    PubMed

    Cruz-Martínez, A; Palau, F

    1997-12-01

    A follow-up clinical study, peripheral motor and sensory nerve conduction velocities and central motor conduction by magnetic stimulation of the cortex were performed in 13 patients with classical Friedreich's ataxia (FA) phenotype, for a period of 9-12 years. Clinical worsening was unrelated to peripheral nerve abnormalities. The amplitude of the nerve action potentials and delayed conduction velocity remained unchanged for several years. Central motor conduction times were abnormal in all patients. Clinical conditions worsened significantly between successive examinations with significant increments in threshold and significant decrement of the amplitude of motor evoked potentials. The results are consistent with progressive pyramidal and cerebellar pathways involvement as the cause of clinical worsening in FA.

  6. Combined KHFAC + DC nerve block without onset or reduced nerve conductivity after block

    NASA Astrophysics Data System (ADS)

    Franke, Manfred; Vrabec, Tina; Wainright, Jesse; Bhadra, Niloy; Bhadra, Narendra; Kilgore, Kevin

    2014-10-01

    Objective. Kilohertz frequency alternating current (KHFAC) waveforms have been shown to provide peripheral nerve conductivity block in many acute and chronic animal models. KHFAC nerve block could be used to address multiple disorders caused by neural over-activity, including blocking pain and spasticity. However, one drawback of KHFAC block is a transient activation of nerve fibers during the initiation of the nerve block, called the onset response. The objective of this study is to evaluate the feasibility of using charge balanced direct current (CBDC) waveforms to temporarily block motor nerve conductivity distally to the KHFAC electrodes to mitigate the block onset-response. Approach. A total of eight animals were used in this study. A set of four animals were used to assess feasibility and reproducibility of a combined KHFAC + CBDC block. A following randomized study, conducted on a second set of four animals, compared the onset response resulting from KHFAC alone and combined KHFAC + CBDC waveforms. To quantify the onset, peak forces and the force-time integral were measured during KHFAC block initiation. Nerve conductivity was monitored throughout the study by comparing muscle twitch forces evoked by supra-maximal stimulation proximal and distal to the block electrodes. Each animal of the randomized study received at least 300 s (range: 318-1563 s) of cumulative dc to investigate the impact of combined KHFAC + CBDC on nerve viability. Main results. The peak onset force was reduced significantly from 20.73 N (range: 18.6-26.5 N) with KHFAC alone to 0.45 N (range: 0.2-0.7 N) with the combined CBDC and KHFAC block waveform (p < 0.001). The area under the force curve was reduced from 6.8 Ns (range: 3.5-21.9 Ns) to 0.54 Ns (range: 0.18-0.86 Ns) (p < 0.01). No change in nerve conductivity was observed after application of the combined KHFAC + CBDC block relative to KHFAC waveforms. Significance. The distal application of CBDC can significantly reduce or even

  7. Electrical stimulation of nerve cells using conductive nanofibrous scaffolds for nerve tissue engineering.

    PubMed

    Ghasemi-Mobarakeh, Laleh; Prabhakaran, Molamma P; Morshed, Mohammad; Nasr-Esfahani, Mohammad Hossein; Ramakrishna, Seeram

    2009-11-01

    Fabrication of scaffolds with suitable chemical, mechanical, and electrical properties is critical for the success of nerve tissue engineering. Electrical stimulation was directly applied to electrospun conductive nanofibrous scaffolds to enhance the nerve regeneration process. In the present study, electrospun conductive nanofibers were prepared by mixing 10 and 15 wt% doped polyaniline (PANI) with poly (epsilon-caprolactone)/gelatin (PG) (70:30) solution (PANI/PG) by electrospinning. The fiber diameter, pore size, hydrophilicity, tensile properties, conductivity, Fourier transform infrared (FTIR), and X-ray photoelectron spectroscopy spectra of nanofibers were determined, and the in vitro biodegradability of the different nanofibrous scaffolds was also evaluated. Nanofibrous scaffolds containing 15% PANI was found to exhibit the most balanced properties to meet all the required specifications for electrical stimulation for its enhanced conductivity and is used for in vitro culture and electrical stimulation of nerve stem cells. 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay and scanning electron microscopy results showed that conductive nanofibrous scaffolds are suitable substrates for the attachment and proliferation of nerve stem cells. Electrical stimulation through conductive nanofibrous PANI/PG scaffolds showed enhanced cell proliferation and neurite outgrowth compared to the PANI/PG scaffolds that were not subjected to electrical stimulation.

  8. Differential fiber-specific block of nerve conduction in mammalian peripheral nerves using kilohertz electrical stimulation

    PubMed Central

    Patel, Yogi A.

    2015-01-01

    Kilohertz electrical stimulation (KES) has been shown to induce repeatable and reversible nerve conduction block in animal models. In this study, we characterized the ability of KES stimuli to selectively block specific components of stimulated nerve activity using in vivo preparations of the rat sciatic and vagus nerves. KES stimuli in the frequency range of 5–70 kHz and amplitudes of 0.1–3.0 mA were applied. Compound action potentials were evoked using either electrical or sensory stimulation, and block of components was assessed through direct nerve recordings and muscle force measurements. Distinct observable components of the compound action potential had unique conduction block thresholds as a function of frequency of KES. The fast component, which includes motor activity, had a monotonically increasing block threshold as a function of the KES frequency. The slow component, which includes sensory activity, showed a nonmonotonic block threshold relationship with increasing KES frequency. The distinct trends with frequency of the two components enabled selective block of one component with an appropriate choice of frequency and amplitude. These trends in threshold of the two components were similar when studying electrical stimulation and responses of the sciatic nerve, electrical stimulation and responses of the vagus nerve, and sensorimotor stimulation and responses of the sciatic nerve. This differential blocking effect of KES on specific fibers can extend the applications of KES conduction block to selective block and stimulation of neural signals for neuromodulation as well as selective control of neural circuits underlying sensorimotor function. PMID:25878155

  9. Intelligence, Reaction Times, and Peripheral Nerve Conduction Velocity.

    ERIC Educational Resources Information Center

    Vernon, Philip A.; Mori, Monica

    1992-01-01

    In 2 studies with 85 and 88 undergraduates, respectively, peripheral nerve conduction velocity (NCV) was significantly correlated with IQ score and reaction times, and NCV and reaction time contributed significantly, in combination, to prediction of IQ. Results are interpreted in terms of a neural efficiency model of intelligence. (Author/SLD)

  10. Inhibition of nerve conduction by electromagnetic induction of the frog sciatic nerve-gastrocnemius muscle preparation.

    PubMed

    Wali, F A; Brain, A I

    1989-01-01

    The effect of electromagnetic induction (EMI) on impulse conduction and muscle contraction was studied in isolated sciatic nerve-gastrocnemius muscle preparation of the frog. Electrical stimulation (ES) of the sciatic nerve, at 0.5 Hz with 0.6 V (supramaximal) and 1-ms pulse duration, produced twitch contractions (3.5 +/- 0.4 g tension, mean +/- S.E., n = 8 frogs), which were reduced or blocked by EMI, applied to the nerve via an induction coil, from a d.c. source of 1.5-4 V, at a frequency of 100 min-1, for 2- to 4-min duration. Recovery of the blocked twitches was obtained within 4-5 min, after the cessation of the EMI and washing out the preparation in Ringer solution. The inhibition of the twitch tension by EMI was compared to that produced by an effective concentration of a local anaesthetic, lignocaine (1 microM), which is known to block conduction, by blocking ionic fluxes across the nerve membrane. It is possible that EMI also interferes with the ionic fluxes, and in prolonged duration, may produce changes in the myelin sheath (or the Schwann cells) of the nerve membrane. A comparison of ES with EMI was made, and it was concluded that EMI inhibited electrically induced neuromuscular transmission at the frog neuromuscular junction.

  11. Morphometric Brain Abnormalities in Boys with Conduct Disorder

    ERIC Educational Resources Information Center

    Huebner, Thomas; Vloet, Timo D.; Marx, Ivo; Konrad, Kerstin; Fink, Gereon R.; Herpertz, Sabine C.; Herpertz-Dahlmann, Beate

    2008-01-01

    Conduct disorder (CD) is associated with antisocial personality behavior that violates the basic rights of others. Results, on examining the structural brain aberrations in boys' CD, show that boys with CD and cormobid attention-deficit/hyperactivity disorder showed abnormalities in frontolimbic areas that could contribute to antisocial…

  12. Hydraulic conductance of Acacia phyllodes (foliage) is driven by primary nerve (vein) conductance and density.

    PubMed

    Sommerville, Katy E; Sack, Lawren; Ball, Marilyn C

    2012-01-01

    We determined effects of venation traits on hydraulic conductance of phyllodes (foliage), using an array of Acacia s.str. species with diverse phyllode morphologies as the source of variation. Measurements were made on phyllodes from 44 species, grown in common gardens but originating from different positions along a precipitation gradient. K(phyllode) varied 18-fold and was positively correlated with primary nerve hydraulic conductance, and with primary nerve (vein) density but not with minor nerve density, in contrast with previous studies of true leaves in other dicotyledons. Phyllodes with higher primary nerve density also had greater mass per area (PMA) and larger bundle sheath extensions (BSEs) from their minor nerves. We suggest that higher primary nerve conductivity and density may decrease the distance travelled in the high-resistance extra-xylem pathways of the phyllode. Further, larger BSEs may increase the area available for dispersion of water from the xylem to the extra-xylem tissue. High PMA phyllodes were more common in acacias from areas receiving lower annual precipitation. Maximizing efficient water movement through phyllodes may be more important where rainfall is meagre and infrequent, explaining relationships between nerve patterns and the climates of origin in Australian phyllodinous Acacia.

  13. Peripheral nerve conduction and central motor conduction after magnetic stimulation of the brain in myotonic dystrophy.

    PubMed

    Cruz Martínez, A

    1992-06-01

    Central motor conduction time was calculated after magnetic stimulation of the brain in 15 patients with myotonic dystrophy and in 38 healthy voluntaries of the same age. Conventional electromyography and motor and sensory conduction velocities were also performed. Central motor conduction time from vertex to C8 was within the normal range in all patients whereas motor conduction velocity of the peripheral nerve and amplitude of the nerve evoked potentials were slightly reduced in 3 and 2 cases respectively, supporting peripheral nerve involvement in some subjects. Our results suggest that the reported central nervous system involvement in myotonic dystrophy, including the nonspecific white matter lesions showed by magnetic resonance imaging, would not affect the conduction of the corticospinal tracts. Magnetic stimulation on the motor cortex is a painless method to study the central nervous system and apports a satisfactory approximation to central motor pathways conduction.

  14. Conduction failures in rabbit saphenous nerve unmyelinated fibers.

    PubMed

    Zhu, Zhi-Ru; Tang, Xiao-Wei; Wang, Wen-Ting; Ren, Wei; Xing, Jun-Ling; Zhang, Jun-Ran; Duan, Jian-Hong; Wang, Yu-Ying; Jiao, Xiying; Hu, San-Jue

    2009-01-01

    Recent experimental and theoretical data indicate that the functional capabilities of axons with specialized structures are much more diverse than traditionally thought. However, few observations were concerned with the main axons without arborization. In the present study, electrical stimulation of the saphenous nerve at different frequencies (2, 5, 10, 20 Hz) was used to test the role of activity-dependent effects on the pattern of action potentials that propagate along individual unmyelinated fibers (C fibers) within the trunk of the saphenous nerve in rabbits. Three basic types of C fiber responses to repetitive stimulation were observed: type-1 fibers showed an entrained response without conduction failure; type-2 fibers discharged with intermittent conduction failures; while only sporadic conduction failures happened in type 3. The failure modality in type-2 and type-3 fibers is closely related to the conductive distance as well as the frequency and duration of stimuli which lead to a critical level of conduction velocity slowing. A novel fluctuation in interspike intervals was always observed immediately before the occurrence of the failures, implying that the fluctuation of conduction velocity is correlated with imminent failures. Both the 4-aminopyridine-sensitive potassium current and hyperpolarization-activated cation current were recognized to be involved in the regulation of conduction failure patterns. The results confirmed, at least in part, the existence of conduction failures in the main axon of C fibers, suggesting that axonal operations may also be determinants for adaptation phenomenon and information processing in peripheral nervous system.

  15. Pre and postoperative median nerve conduction in patients with pituitary tumour.

    PubMed

    Verma, A K; Mahapatra, A K

    1994-07-01

    A study of median nerve sensory conduction at the wrist was performed in 34 patients with pituitary adenomas prior to and following surgery. In 31 patients this was done bilaterally. They included 11 patients with acromegalic features, 3 of whom had features of carpal tunnel syndrome. Six out of 11 (55%) acromegalics had abnormal latencies and conduction velocities pre-operatively. Among the remaining patients only 3 had conduction delay pre-operatively. Postoperative improvement in conduction velocity and latency was recorded in 24 patients although significant improvement was observed in only 13 patients. All 3 patients with carpal tunnel syndrome had significant improvement in conduction velocities and latencies following the surgery. There was no definite relationship between conduction velocity and the pre-operative hormonal profile.

  16. Antibodies to cardiac conducting tissue and abnormalities of cardiac conduction in rheumatoid arthritis.

    PubMed Central

    Villecco, A S; de Liberali, E; Bianchi, F B; Pisi, E

    1983-01-01

    The prevalence of antibodies to cardiac conducting tissue and cardiac conduction electrocardiographic abnormalities were studied in 60 patients with rheumatoid arthritis (RA). Complete or incomplete right bundle branch block (RBBB) was found in 21 patients (35%). Antibodies to cardiac conducting tissue were found in 16 (76%) of the 21 with RBBB and in eight (21%) of the 39 without RBBB. Cardiac conducting tissue antibodies (CCTA) were found only in one of 42 patients with RBBB unrelated to RA and in two out of 60 normal subjects. This newly documented immunological abnormality is thus correlated with disorder of conducting tissue. PMID:6352096

  17. Oculomotor nerve and muscle abnormalities in congenital fibrosis of the extraocular muscles.

    PubMed

    Engle, E C; Goumnerov, B C; McKeown, C A; Schatz, M; Johns, D R; Porter, J D; Beggs, A H

    1997-03-01

    Congenital fibrosis of the extraocular muscles is an autosomal dominant congenital disorder characterized by bilateral ptosis, restrictive external ophthalmoplegia with the eyes partially or completely fixed in an infraducted (downward) and strabismic position, and markedly limited and aberrant residual eye movements. It has been generally thought that these clinical abnormalities result from myopathic fibrosis of the extraocular muscles. We describe the intracranial and orbital pathology of 1 and the muscle pathology of 2 other affected members of a family with chromosome 12-linked congenital fibrosis of the extraocular muscles. There is an absence of the superior division of the oculomotor nerve and its corresponding alpha motor neurons, and abnormalities of the levator palpebrae superioris and rectus superior (the muscles innervated by the superior division of the oculomotor nerve). In addition, increased numbers of internal nuclei and central mitochondrial clumping are found in other extraocular muscles, suggesting that the muscle pathology extends beyond the muscles innervated by the superior division of cranial nerve III. This report presents evidence that congenital fibrosis of the extraocular muscles results from an abnormality in the development of the extraocular muscle lower motor neuron system. PMID:9066352

  18. Reversible Nerve Conduction Block Using Kilohertz Frequency Alternating Current

    PubMed Central

    Kilgore, Kevin L.; Bhadra, Niloy

    2013-01-01

    Objectives The features and clinical applications of balanced-charge kilohertz frequency alternating currents (KHFAC) are reviewed. Preclinical studies of KHFAC block have demonstrated that it can produce an extremely rapid and reversible block of nerve conduction. Recent systematic analysis and experimentation utilizing KHFAC block has resulted in a significant increase in interest in KHFAC block, both scientifically and clinically. Materials and Methods We review the history and characteristics of KHFAC block, the methods used to investigate this type of block, the experimental evaluation of block, and the electrical parameters and electrode designs needed to achieve successful block. We then analyze the existing clinical applications of high frequency currents, comparing the early results with the known features of KHFAC block. Results Although many features of KHFAC block have been characterized, there is still much that is unknown regarding the response of neural structures to rapidly fluctuating electrical fields. The clinical reports to date do not provide sufficient information to properly evaluate the mechanisms that result in successful or unsuccessful treatment. Conclusions KHFAC nerve block has significant potential as a means of controlling nerve activity for the purpose of treating disease. However, early clinical studies in the use of high frequency currents for the treatment of pain have not been designed to elucidate mechanisms or allow direct comparisons to preclinical data. We strongly encourage the careful reporting of the parameters utilized in these clinical studies, as well as the development of outcome measures that could illuminate the mechanisms of this modality. PMID:23924075

  19. Proficiency of Nerve Conduction using Standard Methods and Reference Values (Cl. NPhys Trial 4)

    PubMed Central

    Litchy, William J.; Albers, James W.; Wolfe, James; Bolton, Charles F.; Walsh, Nancy; Klein, Christopher J.; Zafft, Andrew J.; Russell, James W.; Thomas, Karen; Overland, Carol J.; Davies, Jenny L.; Carter, Rickey E.; Dyck, Peter J.

    2014-01-01

    Introduction Cl. NPhys Trial 3 showed that attributes of nerve conduction (NC) were without significant intra-observer differences but showed significant inter-observer differences. Methods Trial 4 tests whether use of written instructions, pre-trial agreement on techniques, and use of standard reference values, diagnostic percentile values, or broader categorization of abnormality reduces significant inter-observer disagreement and improves agreement among clinical neurophysiologists. Results and Discussion The Trial 4 modifications markedly decreased but did not eliminate significant inter-observer differences of measured attributes of NC. Use of standard reference values and defined percentile values of abnormality decreased inter-observer disagreement and improved agreement of judgment of abnormality among evaluators. Therefore, the same clinical neurophysiologist should perform repeat NCs of therapeutic trial patients. Differences in inter-observer judgment of abnormality decrease with use of common standard reference values and a defined percentile level of abnormality, providing a rationale for their use in therapeutic trials and medical practice. PMID:24644133

  20. Effect of superficial peroneal nerve fascial penetration site on nerve conduction studies.

    PubMed

    Park, Geun-Young; Im, Sun; Lee, Jong-In; Lim, Seong-Hoon; Ko, Young-Jin; Chung, Myung-Eun; Hong, Bo-Young; Kim, Hye-Won

    2010-02-01

    Using nerve conduction studies (NCS) and ultrasonography, we sought to determine the stimulation site that corresponds to the site at which the superficial peroneal nerve (SPN) penetrates the fascia and yields the most accurate NCS results. NCS parameters of the SPN sensory nerve action potential (SNAP) were recorded from 37 legs at 14, 12, 9, 7, and 5 cm (S1, S2, S3, S4, and S5, respectively) proximal to the recording electrode, and analyzed by one-way analysis of variance. SPN penetration sites were visualized by ultrasonography. The mean SNAP amplitude/area (17.2 +/- 6.7 microV/9.6 +/- 4.6 microV/ms) at S3-S5 differed significantly from that at S1-S2 (11.6 +/- 4.7 microV/9.2 +/- 4.4 microV/ms) (F = 10.2, P < 0.001; F = 5.09, P = 0.0007). Ultrasonography showed that the SPN became subcutaneous between S3 and S4. Clinical application of these results should help in obtaining more accurate data during electrodiagnostic studies of conditions that involve the SPN.

  1. Spontaneous temporal changes and variability of peripheral nerve conduction analyzed using a random effects model.

    PubMed

    Krøigård, Thomas; Gaist, David; Otto, Marit; Højlund, Dorthe; Selmar, Peter E; Sindrup, Søren H

    2014-08-01

    The reproducibility of variables commonly included in studies of peripheral nerve conduction in healthy individuals has not previously been analyzed using a random effects regression model. We examined the temporal changes and variability of standard nerve conduction measures in the leg. Peroneal nerve distal motor latency, motor conduction velocity, and compound motor action potential amplitude; sural nerve sensory action potential amplitude and sensory conduction velocity; and tibial nerve minimal F-wave latency were examined in 51 healthy subjects, aged 40 to 67 years. They were reexamined after 2 and 26 weeks. There was no change in the variables except for a minor decrease in sural nerve sensory action potential amplitude and a minor increase in tibial nerve minimal F-wave latency. Reproducibility was best for peroneal nerve distal motor latency and motor conduction velocity, sural nerve sensory conduction velocity, and tibial nerve minimal F-wave latency. Between-subject variability was greater than within-subject variability. Sample sizes ranging from 21 to 128 would be required to show changes twice the magnitude of the spontaneous changes observed in this study. Nerve conduction studies have a high reproducibility, and variables are mainly unaltered during 6 months. This study provides a solid basis for the planning of future clinical trials assessing changes in nerve conduction.

  2. Fibrosis, Connexin-43, and Conduction Abnormalities in the Brugada Syndrome

    PubMed Central

    Nademanee, Koonlawee; Raju, Hariharan; de Noronha, Sofia V.; Papadakis, Michael; Robinson, Laurence; Rothery, Stephen; Makita, Naomasa; Kowase, Shinya; Boonmee, Nakorn; Vitayakritsirikul, Vorapot; Ratanarapee, Samrerng; Sharma, Sanjay; van der Wal, Allard C.; Christiansen, Michael; Tan, Hanno L.; Wilde, Arthur A.; Nogami, Akihiko; Sheppard, Mary N.; Veerakul, Gumpanart; Behr, Elijah R.

    2015-01-01

    Background The right ventricular outflow tract (RVOT) is acknowledged to be responsible for arrhythmogenesis in Brugada syndrome (BrS), but the pathophysiology remains controversial. Objectives This study assessed the substrate underlying BrS at post-mortem and in vivo, and the role for open thoracotomy ablation. Methods Six whole hearts from male post-mortem cases of unexplained sudden death (mean age 23.2 years) with negative specialist cardiac autopsy and familial BrS were used and matched to 6 homograft control hearts by sex and age (within 3 years) by random risk set sampling. Cardiac autopsy sections from cases and control hearts were stained with picrosirius red for collagen. The RVOT was evaluated in detail, including immunofluorescent stain for connexin-43 (Cx43). Collagen and Cx43 were quantified digitally and compared. An in vivo study was undertaken on 6 consecutive BrS patients (mean age 39.8 years, all men) during epicardial RVOT ablation for arrhythmia via thoracotomy. Abnormal late and fractionated potentials indicative of slowed conduction were identified, and biopsies were taken before ablation. Results Collagen was increased in BrS autopsy cases compared with control hearts (odds ratio [OR]: 1.42; p = 0.026). Fibrosis was greatest in the RVOT (OR: 1.98; p = 0.003) and the epicardium (OR: 2.00; p = 0.001). The Cx43 signal was reduced in BrS RVOT (OR: 0.59; p = 0.001). Autopsy and in vivo RVOT samples identified epicardial and interstitial fibrosis. This was collocated with abnormal potentials in vivo that, when ablated, abolished the type 1 Brugada electrocardiogram without ventricular arrhythmia over 24.6 ± 9.7 months. Conclusions BrS is associated with epicardial surface and interstitial fibrosis and reduced gap junction expression in the RVOT. This collocates to abnormal potentials, and their ablation abolishes the BrS phenotype and life-threatening arrhythmias. BrS is also associated with increased collagen throughout the heart

  3. Effect of technique variation on sensory nerve conduction characteristics.

    PubMed

    Stone, L A

    1984-04-01

    The impact of technique variation on the wave-form characteristics of the evoked sensory potential was determined from the median and ulnar nerves of healthy subjects. The conduction characteristics of latency, amplitude, and duration were determined for orthodromic and antidromic techniques of stimulation as measured under each of three recording modes: 1) single evoked response, 2) superimposition, and 3) electronic averaging. Variation in the technique of stimulation significantly affected each of the three wave-form characteristics. Peak latency and duration of the evoked sensory potential were longer in antidromic stimulation. The amplitude of the sensory potential varied significantly with both recording and stimulating techniques. The amplitude of the sensory response was larger in antidromic stimulation than in orthodromic stimulation and also was found to be smaller with electronic averaging than with the other recording modes in both antidromic and orthodromic conduction techniques. This degree of variation requires that standardized techniques of methodology be established with the development of normal values for the particular laboratory.

  4. A case of optic-nerve hypoplasia and anterior segment abnormality associated with facial cleft

    PubMed Central

    Miyake, Tomoko; Kojima, Shota; Sugiyama, Tetsuya; Ueki, Mari; Sugasawa, Jun; Oku, Hidehiro; Tajiri, Kensuke; Shigemura, Yuka; Ueda, Koichi; Harada, Atsuko; Yamasaki, Mami; Yamanaka, Takumi; Utsunomiya, Hidetsuna; Ikeda, Tsunehiko

    2016-01-01

    Introduction The incidence of facial cleft is rare and ranges between 1.43 and 4.85 per 100,000 births. To date, there have been few reports of detailed ophthalmologic examinations performed in cases of facial cleft. Here, we report a case of optic-nerve hypoplasia and anterior segment abnormality associated with facial cleft. Case report A 9-day-old female infant was delivered by cesarian section at 34 weeks of gestational age (the second baby of twins) and weighed 2,276 g upon presentation. She had a facial cleft and ectrodactyly at birth. Right eye-dominant blepharophimosis was obvious. Examination of the right eye revealed inferior corneal opacity with vascularization, downward corectopia, and optic-nerve hypoplasia. The corneal diameter was 8 mm in both eyes, and tonometry by use of a Tono-Pen® XL (Reichert Technologies, Depew, NY, USA) handheld applanation tonometer revealed that her intraocular pressure was 11–22 mmHg (Oculus Dexter) and 8 mmHg (Oculus Sinister). B-mode echo revealed no differences in axial length between her right and left eyes. When she was 15–16 months old, we attempted to examine her eyes before she underwent plastic surgery under general anesthesia. She had a small optic disc in both eyes and the right-eye disc was tilted. After undergoing canthotomy, gonioscopy and ultrasound biomicroscopy revealed that almost all directions were open except for the peripheral anterior synechia. Since magnetic resonance imaging revealed ventriculomegaly associated with an interhemispheric cyst at birth, a ventriculoperitoneal shunt was inserted at 12 days of age. At 25 months of age, her condition suddenly deteriorated due to occlusion of the ventricular shunt catheter, and she died 5 days later. In this patient, amniotic band syndrome was presumed to be the primary cause due to the clinical findings. Conclusion We experienced a case of optic-nerve hypoplasia and anterior segment abnormality that occurred with facial cleft. The cause of these

  5. Different clinical electrodes achieve similar electrical nerve conduction block

    NASA Astrophysics Data System (ADS)

    Boger, Adam; Bhadra, Narendra; Gustafson, Kenneth J.

    2013-10-01

    Objective. We aim to evaluate the suitability of four electrodes previously used in clinical experiments for peripheral nerve electrical block applications. Approach. We evaluated peripheral nerve electrical block using three such clinical nerve cuff electrodes (the Huntington helix, the Case self-sizing Spiral and the flat interface nerve electrode) and one clinical intramuscular electrode (the Memberg electrode) in five cats. Amplitude thresholds for the block using 12 or 25 kHz voltage-controlled stimulation, onset response, and stimulation thresholds before and after block testing were determined. Main results. Complete nerve block was achieved reliably and the onset response to blocking stimulation was similar for all electrodes. Amplitude thresholds for the block were lowest for the Case Spiral electrode (4 ± 1 Vpp) and lower for the nerve cuff electrodes (7 ± 3 Vpp) than for the intramuscular electrode (26 ± 10 Vpp). A minor elevation in stimulation threshold and reduction in stimulus-evoked urethral pressure was observed during testing, but the effect was temporary and did not vary between electrodes. Significance. Multiple clinical electrodes appear suitable for neuroprostheses using peripheral nerve electrical block. The freedom to choose electrodes based on secondary criteria such as ease of implantation or cost should ease translation of electrical nerve block to clinical practice.

  6. Nerve Conduction Block Using Combined Thermoelectric Cooling and High Frequency Electrical Stimulation

    PubMed Central

    Ackermann, D. Michael; Foldes, Emily L.; Bhadra, Niloy; Kilgore, Kevin L.

    2010-01-01

    Conduction block of peripheral nerves is an important technique for many basic and applied neurophysiology studies. To date, there has not been a technique which provides a quickly initiated and reversible “on-demand” conduction block which is both sustainable for long periods of time and does not generate activity in the nerve at the onset of the conduction block. In this study we evaluated the feasibility of a combined method of nerve block which utilizes two well established nerve blocking techniques in a rat and cat model: nerve cooling and electrical block using high frequency alternating currents (HFAC). This combined method effectively makes use of the contrasting features of both nerve cooling and electrical block using HFAC. The conduction block was initiated using nerve cooling, a technique which does not produce nerve “onset response” firing, a prohibitive drawback of HFAC electrical block. The conduction block was then readily transitioned into an electrical block. A long-term electrical block is likely preferential to a long-term nerve cooling block because nerve cooling block generates large amounts of exhaust heat, does not allow for fiber diameter selectivity and is known to be unsafe for prolonged delivery. PMID:20705099

  7. Nerve conduction block using combined thermoelectric cooling and high frequency electrical stimulation.

    PubMed

    Ackermann, D Michael; Foldes, Emily L; Bhadra, Niloy; Kilgore, Kevin L

    2010-10-30

    Conduction block of peripheral nerves is an important technique for many basic and applied neurophysiology studies. To date, there has not been a technique which provides a quickly initiated and reversible "on-demand" conduction block which is both sustainable for long periods of time and does not generate activity in the nerve at the onset of the conduction block. In this study we evaluated the feasibility of a combined method of nerve block which utilizes two well established nerve blocking techniques in a rat and cat model: nerve cooling and electrical block using high frequency alternating currents (HFAC). This combined method effectively makes use of the contrasting features of both nerve cooling and electrical block using HFAC. The conduction block was initiated using nerve cooling, a technique which does not produce nerve "onset response" firing, a prohibitive drawback of HFAC electrical block. The conduction block was then readily transitioned into an electrical block. A long-term electrical block is likely preferential to a long-term nerve cooling block because nerve cooling block generates large amounts of exhaust heat, does not allow for fiber diameter selectivity and is known to be unsafe for prolonged delivery.

  8. Abnormal intracellular calcium homeostasis associated with vulnerability in the nerve cells from heroin-dependent rat.

    PubMed

    Liu, Xiaoshan; Wang, Guangyong; Pu, Hongwei; Jing, Hualan

    2014-07-14

    The cellular mechanisms by which opiate addiction develops with repetitive use remain largely unresolved. Intercellular calcium homeostasis is one of the most critical elements to determine neuroadaptive changes and neuronal fate. Heroin, one of the most addictive opiates, may induce neurotoxicity potentially inducing brain impairment, especially for those chronic users who get an overdose. Here we examined changes in intracellular calcium concentration ([Ca2+]i) after repeated exposure to heroin using cultured cerebral cortical neurons. Dynamic changes in [Ca2+]i indicated by fluo-3-AM were monitored using confocal laser scan microscopy, followed by cytotoxicity assessments. It showed that the cells dissociated from heroin-dependent rats had a smaller depolarization-induced [Ca2+]i responses, and a higher elevation in [Ca2+]i when challenged with a high concentration of heroin (500 μM). The restoration ability to remove calcium after washout of these stimulants was impaired. Calcium channel blocker verapamil inhibited the heroin-induced [Ca2+]i elevations as well as the heroin-induced cell damage. The relative [Ca2+]i of the nerve cells closely correlated with the number of damaged cells induced by heroin. These results demonstrate that nerve cells from heroin-dependent rats manifest abnormal [Ca2+]i homeostasis, as well as vulnerability to heroin overdose, suggesting involvement of [Ca2+]i regulation mechanisms in heroin addiction and neurotoxicity.

  9. Nerve Conduction in the Pre-Medical Physics Course

    ERIC Educational Resources Information Center

    Hobbie, Russell K.

    1973-01-01

    Reviews properties of nerves, analogous networks in propagation of electrical signals in axons, and regenerative changes in membrane permeability due to propagation of the action potential, which can be explained in the noncalculus physics course. (CC)

  10. High frequency electrical conduction block of the pudendal nerve

    NASA Astrophysics Data System (ADS)

    Bhadra, Narendra; Bhadra, Niloy; Kilgore, Kevin; Gustafson, Kenneth J.

    2006-06-01

    A reversible electrical block of the pudendal nerves may provide a valuable method for restoration of urinary voiding in individuals with bladder-sphincter dyssynergia. This study quantified the stimulus parameters and effectiveness of high frequency (HFAC) sinusoidal waveforms on the pudendal nerves to produce block of the external urethral sphincter (EUS). A proximal electrode on the pudendal nerve after its exit from the sciatic notch was used to apply low frequency stimuli to evoke EUS contractions. HFAC at frequencies from 1 to 30 kHz with amplitudes from 1 to 10 V were applied through a conforming tripolar nerve cuff electrode implanted distally. Sphincter responses were recorded with a catheter mounted micro-transducer. A fast onset and reversible motor block was obtained over this range of frequencies. The HFAC block showed three phases: a high onset response, often a period of repetitive firing and usually a steady state of complete or partial block. A complete EUS block was obtained in all animals. The block thresholds showed a linear relationship with frequency. HFAC pudendal nerve stimulation effectively produced a quickly reversible block of evoked urethral sphincter contractions. The HFAC pudendal block could be a valuable tool in the rehabilitation of bladder-sphincter dyssynergia.

  11. Effect of Limb Lengthening on Internodal Length and Conduction Velocity of Peripheral Nerve

    PubMed Central

    Gillingwater, Thomas H.; Anderson, Heather; Cottrell, David; Sherman, Diane L.; Ribchester, Richard R.; Brophy, Peter J.

    2013-01-01

    The influences of axon diameter, myelin thickness, and internodal length on the velocity of conduction of peripheral nerve action potentials are unclear. Previous studies have demonstrated a strong dependence of conduction velocity on internodal length. However, a theoretical analysis has suggested that this relationship may be lost above a nodal separation of ∼0.6 mm. Here we measured nerve conduction velocities in a rabbit model of limb lengthening that produced compensatory increases in peripheral nerve growth. Divided tibial bones in one hindlimb were gradually lengthened at 0.7 mm per day using an external frame attached to the bone. This was associated with a significant increase (33%) of internodal length (0.95–1.3 mm) in axons of the tibial nerve that varied in proportion to the mechanical strain in the nerve of the lengthened limb. Axonal diameter, myelin thickness, and g-ratios were not significantly altered by limb lengthening. Despite the substantial increase in internodal length, no significant change was detected in conduction velocity (∼43 m/s) measured either in vivo or in isolated tibial nerves. The results demonstrate that the internode remains plastic in the adult but that increases in internodal length of myelinated adult nerve axons do not result in either deficiency or proportionate increases in their conduction velocity and support the view that the internodal lengths of nerves reach a plateau beyond which their conduction velocities are no longer sensitive to increases in internodal length. PMID:23467369

  12. Effect of magnesium on nerve conduction velocity during regular dialysis treatment

    PubMed Central

    Fleming, Laura W.; Lenman, J. A. R.; Stewart, W. K.

    1972-01-01

    Serial nerve conduction velocities in the peroneal and ulnar nerves have been measured in 10 patients on regular dialysis treatment over a three year period. Each patient alternated between phases on dialysis with magnesium-containing dialysate (1·5-1·7 m-equiv/l.) and phases on `magnesium-free' dialysate (0·2 m-equiv/l.). Plasma magnesium concentrations were high both pre- and post-dialysis during magnesium-containing dialysis, and normal to low on magnesium-free dialysis. All patients had defects in nerve conduction, mainly asymptomatic. Increases in nerve conduction velocity coincided with magnesium-free dialysis, and decreases occurred when the patients reverted to magnesium-containing dialysate. The significance of the correlation by the sign test was P<0·0005. It is concluded that extracellular magnesium levels can influence the rate of nerve conduction in vivo. PMID:4338446

  13. Diagnosis of Severe Carpal Tunnel Syndrome Using Nerve Conduction Study and Ultrasonography.

    PubMed

    Fujimoto, Kazuhiro; Kanchiku, Tsukasa; Kido, Kenji; Imajo, Yasuaki; Funaba, Masahiro; Taguchi, Toshihiko

    2015-10-01

    This study investigated the correlation between nerve conduction study and ultrasonographic findings for assessment of the usefulness of ultrasonography in determining carpal tunnel syndrome severity. Hands of adults with carpal tunnel syndrome were assessed using ultrasound and nerve conduction studies and grouped according to median nerve cross-sectional area (CSA). There were significant differences (p < 0.01) in mean median nerve CSA between controls, patients with median sensory nerve conduction velocity ≤40 m/s and patients with absent sensory nerve action potential and between controls, patients with median nerve distal motor latency ≥4.5 ms and patients with absent compound muscle action potentials of the abductor pollicis brevis. This is the first report to define median nerve CSA cutoff values (18 mm(2)) for determining carpal tunnel syndrome severity in patients with absent compound muscle action potentials of the abductor pollicis brevis. Median nerve CSA values below the cutoff values should prompt clinicians to consider other disorders, such as cervical compressive myelopathy.

  14. The Study of Diagnostic Efficacy of Nerve Conduction Study Parameters in Cervical Radiculopathy

    PubMed Central

    Pawar, Sachin; Kashikar, Aditi; Shende, Vinod; Waghmare, Satish

    2013-01-01

    Background: Cervical Radiculopathy (CR) is a neurologic condition characterised by dysfunction of a cervical spinal nerve, the roots of the nerve, or both. Diagnostic criteria for CR are not well defined, and no universally accepted criteria for its diagnosis have been established. Clinical examination, radiological imaging and electrophysiologic evaluation are the different modalities to diagnose CR. The incidence of Cervical Spondylosis and related conditions is increasing in the present scenario and the use of radiologic examination is time consuming and uneconomical for the common Indian setup. Thus, there is a definite need to establish a cost effective, reliable, and accurate means for establishing the diagnosis of cervical radiculopathy. Electrodiagnostic tests are the closest to fulfill these criteria. Aim: To evaluate diagnostic utility of various motor and sensory nerve conduction study parameters in cervical radiculopathy. Setting and Design: It was a cross-sectional study conducted on 100 subjects of age > 40 years. Material and Methods: The consecutive patients clinically diagnosed to have cervical radiculopathy, referred from department of Orthopaedics were prospectively recruited for the motor and sensory nerve conduction study using RMS EMG EP Mark-II. Parameters studied were Compound Muscle Action Potential (CMAP), Distal Motor Latency (DML) and Conduction Velocity (CV) for motor nerves and Sensory Nerve Action Potential (SNAP) and CV for sensory nerves. Statistical Analysis: Study observations and results were analysed to find the Specificity, Sensitivity, Positive Predictive Value and Negative Predictive Value using SPSS 16.0. Results: Among various motor nerve conduction parameters CMAP was found to be more sensitive with high positive predicative value. CV was found to have greater specificity and DML had least negative predictive value. Sensory nerve conduction parameters were found to have less sensitivity but higher specificity as compared

  15. The Relationship between Nerve Conduction Study and Clinical Grading of Carpal Tunnel Syndrome

    PubMed Central

    Cheluvaiah, Janardhan D.; Agadi, Jagadish B.; Nagaraj, Karthik

    2016-01-01

    Introduction Carpal Tunnel Syndrome (CTS) is the most common nerve entrapment. Subjective sensory symptoms are common place in patients with CTS, but sometimes they are not supported by objective findings in the neurological examination. Electrodiagnostic (EDx) studies are a valid and reliable means of confirming the diagnosis. The amplitudes along with the conduction velocities of the sensory nerve action potential and motor nerve action potential reflect the functional state of axons, and are useful parameters and complement the clinical grading in the assessment of severity of CTS. Aim To conduct median nerve sensory and motor conduction studies on patients with carpal tunnel syndrome and correlate the relationship between nerve conduction study parameters and the clinical severity grading. Materials and Methods Based on clinical assessment, the study patients were divided into 03 groups with mild CTS, moderate CTS and severe CTS respectively as per Mackinnson’s classification. Median and ulnar nerve conduction studies were performed on bilateral upper limbs of 50 patients with symptoms of CTS and 50 age and sex matched healthy control subjects. The relationship between the clinical severity grade and various nerve conduction study parameters were correlated. Results In this prospective case control study, 50 patients with symptoms consistent with CTS and 50 age and sex matched healthy control subjects were examined over a 10 month period. A total of 30 patients had unilateral CTS (right upper limb in 19 and left upper limb in 11) and 20 patients had bilateral CTS. Female to male ratio was 3.54 to 1. Age ranged from 25 to 81 years. The mean age at presentation was 49.68±11.7 years. Tingling paresthesias of hand and first three fingers were the most frequent symptoms 48 (98%). Tinel’s and Phalen’s sign were positive in 36 (72%) and 44 (88%) patients respectively. The mean duration of symptoms at presentation was 52.68±99.81 weeks. 16 patients (32%) had

  16. The Relationship between Nerve Conduction Study and Clinical Grading of Carpal Tunnel Syndrome

    PubMed Central

    Cheluvaiah, Janardhan D.; Agadi, Jagadish B.; Nagaraj, Karthik

    2016-01-01

    Introduction Carpal Tunnel Syndrome (CTS) is the most common nerve entrapment. Subjective sensory symptoms are common place in patients with CTS, but sometimes they are not supported by objective findings in the neurological examination. Electrodiagnostic (EDx) studies are a valid and reliable means of confirming the diagnosis. The amplitudes along with the conduction velocities of the sensory nerve action potential and motor nerve action potential reflect the functional state of axons, and are useful parameters and complement the clinical grading in the assessment of severity of CTS. Aim To conduct median nerve sensory and motor conduction studies on patients with carpal tunnel syndrome and correlate the relationship between nerve conduction study parameters and the clinical severity grading. Materials and Methods Based on clinical assessment, the study patients were divided into 03 groups with mild CTS, moderate CTS and severe CTS respectively as per Mackinnson’s classification. Median and ulnar nerve conduction studies were performed on bilateral upper limbs of 50 patients with symptoms of CTS and 50 age and sex matched healthy control subjects. The relationship between the clinical severity grade and various nerve conduction study parameters were correlated. Results In this prospective case control study, 50 patients with symptoms consistent with CTS and 50 age and sex matched healthy control subjects were examined over a 10 month period. A total of 30 patients had unilateral CTS (right upper limb in 19 and left upper limb in 11) and 20 patients had bilateral CTS. Female to male ratio was 3.54 to 1. Age ranged from 25 to 81 years. The mean age at presentation was 49.68±11.7 years. Tingling paresthesias of hand and first three fingers were the most frequent symptoms 48 (98%). Tinel’s and Phalen’s sign were positive in 36 (72%) and 44 (88%) patients respectively. The mean duration of symptoms at presentation was 52.68±99.81 weeks. 16 patients (32%) had

  17. Polychlorinated biphenyl poisoning: correlation of sensory and motor nerve conduction, neurologic symptoms, and blood levels of polychlorinated biphenyls, quaterphenyls, and dibenzofurans

    SciTech Connect

    Chen, R.C.; Tang, S.Y.; Miyata, H.; Kashimoto, T.; Chang, Y.C.; Chang, K.J.; Tung, T.C.

    1985-08-01

    In 1979 in Taiwan, more than 2000 people were poisoned with rice cooking oil contaminated with polychlorinated biphenyls (PCB). One hundred ten patients were studied within one year of the exposure. The blood PCB levels were 39.3 +/- 16.6 ppb. The blood levels of the PCB derivatives, polychlorinated quaterphenyls (PCQ) and polychlorinated dibenzofurans (PCDF), were 8.6 +/- 4.8 and 0.076 +/- 0.038 ppb, respectively. Both the sensory and motor nerve conduction velocities (NCV) of the patients were significantly lower than the control. Abnormal slowing of sensory NCV was found in 43.6% and abnormal slowing of motor NCV was seen in 21.8%. Patients who had higher PCQ blood levels has significantly slower median nerve sensory NCV than those with lower PCQ levels. Patients with higher PCB blood levels had significantly slower peroneal nerve motor NCV than those with lower PCB levels.

  18. Microstructural abnormalities of the trigeminal nerve by diffusion-tensor imaging in trigeminal neuralgia without neurovascular compression.

    PubMed

    Neetu, Soni; Sunil, Kumar; Ashish, Awasthi; Jayantee, Kalita; Usha Kant, Misra

    2016-02-01

    Microstructural changes of the trigeminal nerve in trigeminal neuralgia due to neurovascular compression have been reported by using diffusion tensor imaging. Other aetiologies such as primary demyelinating lesions, brain stem infarction and nerve root infiltration by tumour affecting the trigeminal pathway may also present as trigeminal neuralgia. The aim of this study was to evaluate the microstructural tissue abnormalities in the trigeminal nerve in symptomatic trigeminal neuralgia not related to neurovascular compression using diffusion tensor imaging. Mean values of the quantitative diffusion parameters of trigeminal nerve, fractional anisotropy and apparent diffusion coefficient, were measured in a group of four symptomatic trigeminal neuralgia patients without neurovascular compression who showed focal non-enhancing T2-hyperintense lesions in the pontine trigeminal pathway. These diffusion parameters were compared between the affected and unaffected sides in the same patient and with four age-matched healthy controls. Cranial magnetic resonance imaging revealed hyperintense lesions in the dorsolateral part of the pons along the central trigeminal pathway on T2-fluid-attenuated inversion recovery sequences. The mean fractional anisotropy value on the affected side was significantly decreased (P = 0.001) compared to the unaffected side and healthy controls. Similarly, the mean apparent diffusion coefficient value was significantly higher (P = 0.001) on the affected side compared to the unaffected side and healthy controls. The cause of trigeminal neuralgia in our patients was abnormal pontine lesions affecting the central trigeminal pathway. The diffusion tensor imaging results suggest that microstructural tissue abnormalities of the trigeminal nerve also exist even in non-neurovascular compression-related trigeminal neuralgia.

  19. Mice Lacking GD3 Synthase Display Morphological Abnormalities in the Sciatic Nerve and Neuronal Disturbances during Peripheral Nerve Regeneration

    PubMed Central

    Ribeiro-Resende, Victor Túlio; Gomes, Tiago Araújo; de Lima, Silmara; Nascimento-Lima, Maiara; Bargas-Rega, Michele; Santiago, Marcelo Felipe; Reis, Ricardo Augusto de Melo; de Mello, Fernando Garcia

    2014-01-01

    The ganglioside 9-O-acetyl GD3 is overexpressed in peripheral nerves after lesioning, and its expression is correlated with axonal degeneration and regeneration in adult rodents. However, the biological roles of this ganglioside during the regenerative process are unclear. We used mice lacking GD3 synthase (Siat3a KO), an enzyme that converts GM3 to GD3, which can be further converted to 9-O-acetyl GD3. Morphological analyses of longitudinal and transverse sections of the sciatic nerve revealed significant differences in the transverse area and nerve thickness. The number of axons and the levels of myelin basic protein were significantly reduced in adult KO mice compared to wild-type (WT) mice. The G-ratio was increased in KO mice compared to WT mice based on quantification of thin transverse sections stained with toluidine blue. We found that neurite outgrowth was significantly reduced in the absence of GD3. However, addition of exogenous GD3 led to neurite growth after 3 days, similar to that in WT mice. To evaluate fiber regeneration after nerve lesioning, we compared the regenerated distance from the lesion site and found that this distance was one-fourth the length in KO mice compared to WT mice. KO mice in which GD3 was administered showed markedly improved regeneration compared to the control KO mice. In summary, we suggest that 9-O-acetyl GD3 plays biological roles in neuron-glia interactions, facilitating axonal growth and myelination induced by Schwann cells. Moreover, exogenous GD3 can be converted to 9-O-acetyl GD3 in mice lacking GD3 synthase, improving regeneration. PMID:25330147

  20. Abnormal Origin and Course of the Accessory Phrenic Nerve: Case Report.

    PubMed

    Paraskevas, George; Koutsouflianiotis, Konstantinos; Kitsoulis, Panagiotis; Spyridakis, Ioannis

    2016-01-01

    In the current cadaveric study an unusual sizeable accessory phrenic nerve (APN) was encountered emerging from the trunk of the supraclavicular nerves and forming a triangular loop that was anastomosing with the phrenic nerve. That neural loop surrounded the superficial cervical artery which displayed a spiral course. The form of a triangular loop of APN involving the aforementioned artery and originating from the supraclavicular nerve to the best of our knowledge has not been documented previously in the literature. The variable morphological features of the APN along with its clinical applications are briefly discussed. PMID:27526310

  1. Brain Structure Abnormalities in Adolescent Girls with Conduct Disorder

    ERIC Educational Resources Information Center

    Fairchild, Graeme; Hagan, Cindy C.; Walsh, Nicholas D.; Passamonti, Luca; Calder, Andrew J.; Goodyer, Ian M.

    2013-01-01

    Background: Conduct disorder (CD) in female adolescents is associated with a range of negative outcomes, including teenage pregnancy and antisocial personality disorder. Although recent studies have documented changes in brain structure and function in male adolescents with CD, there have been no neuroimaging studies of female adolescents with CD.…

  2. Effect of pulsed infrared lasers on neural conduction and axoplasmic transport in sensory nerves

    NASA Astrophysics Data System (ADS)

    Wesselmann, Ursula; Rymer, William Z.; Lin, Shien-Fong

    1990-06-01

    Over the past ten years there has been an increasing interest in the use of lasers for neurosurgical and neurological procedures. Novel recent applications range from neurosurgical procedures such as dorsal root entry zone lesions made with argon and carbon dioxide microsurgical lasers to pain relief by low power laser irradiation of the appropriate painful nerve or affected region1 '2 However, despite the widespread clinical applications of laser light, very little is known about the photobiological interactions between laser light and nervous tissue. The present studies were designed to evaluate the effects of pulsed Nd:YAG laser light on neural impulse conduction and axoplasmic transport in sensory nerves in rats and cats. Our data indicate that Q-switched Nd:YAG laser irradiation can induce a preferential impairment of (1) the synaptic effects of small afferent fibers on dorsal horn cells in the spinal cord and of (2) small slow conducting sensory nerve fibers in dorsal roots and peripheral nerves. These results imply that laser light might have selective effects on impulse conduction in slow conducting sensory nerve fibers. In agreement with our elecirophysiological observations recent histological data from our laboratory show, that axonal transport of the enzyme horseradish peroxidase is selectively impaired in small sensory nerve fibers. In summary these data indicate, that Q-switched Nd:YAG laser irradiation can selectively impair neural conduction and axoplasmic transport in small sensory nerve fibers as compared to fast conducting fibers. A selective influence of laser irradiation on slow conducting fibers could have important clinical applications, especially for the treatment of chronic pain.

  3. Conduction abnormalities and ventricular arrhythmogenesis: The roles of sodium channels and gap junctions

    PubMed Central

    Tse, Gary; Yeo, Jie Ming

    2015-01-01

    Ventricular arrhythmias arise from disruptions in the normal orderly sequence of electrical activation and recovery of the heart. They can be categorized into disorders affecting predominantly cellular depolarization or repolarization, or those involving action potential (AP) conduction. This article briefly discusses the factors causing conduction abnormalities in the form of unidirectional conduction block and reduced conduction velocity (CV). It then examines the roles that sodium channels and gap junctions play in AP conduction. Finally, it synthesizes experimental results to illustrate molecular mechanisms of how abnormalities in these proteins contribute to such conduction abnormalities and hence ventricular arrhythmogenesis, in acquired pathologies such as acute ischaemia and heart failure, as well as inherited arrhythmic syndromes. PMID:26839915

  4. Effect of Elbow Position on Short-segment Nerve Conduction Study in Cubital Tunnel Syndrome

    PubMed Central

    Liu, Zhu; Jia, Zhi-Rong; Wang, Ting-Ting; Shi, Xin; Liang, Wei

    2016-01-01

    Background: The appropriate elbow position of short-segment nerve conduction study (SSNCS) to diagnose cubital tunnel syndrome (CubTS) is still controversial. The goal of this study was to determine the effect of different elbow positions at full extension and 70° flexion on SSNCS in CubTS. Methods: In this cross-sectional study, the clinical data of seventy elbows from 59 CubTS patients between September, 2011 and December, 2014 in the Peking University First Hospital were included as CubTS group. Moreover, thirty healthy volunteers were included as the healthy group. SSNCS were conducted in all subjects at elbow full extension and 70° elbow flexion. Paired nonparametric test, bivariate correlation, Bland–Altman, and Chi-squared test analysis were used to compare the effectiveness of elbow full extension and 70° flexion elbow positions on SSNCS in CubTS patients. Results: Data of upper limit was calculated from healthy group, and abnormal latency was judged accordingly. CubTS group's latency and compound muscle action potential (CMAP) of each segment at 70° elbow flexion by SSNCS was compared with full extension position, no statistically significant difference were found (all P > 0.05). Latency and CMAP of each segment at elbow full extension and 70° flexion were correlated (all P < 0.01), except the latency of segment of 4 cm to 6 cm above elbow (P = 0.43), and the latency (P = 0.15) and the CMAP (P = 0.06) of segment of 2 cm to 4 cm below elbow. Bivariate correlation and Bland–Altman analysis proved the correlation between elbow full extension and 70° flexion. Especially in segments across the elbow (2 cm above the elbow and 2 cm below it), latency at elbow full extension and 70° flexion were strong direct associated (r = 0.83, P < 0.01; r = 0.55, P < 0.01), and so did the CMAP (r = 0.49, P < 0.01; r = 0.72, P < 0.01). There was no statistically significant difference in abnormality of each segment at full extension as measured by SSNCS compared with

  5. Application of conductive polymers, scaffolds and electrical stimulation for nerve tissue engineering.

    PubMed

    Ghasemi-Mobarakeh, Laleh; Prabhakaran, Molamma P; Morshed, Mohammad; Nasr-Esfahani, Mohammad Hossein; Baharvand, Hossein; Kiani, Sahar; Al-Deyab, Salem S; Ramakrishna, Seeram

    2011-04-01

    Among the numerous attempts to integrate tissue engineering concepts into strategies to repair nearly all parts of the body, neuronal repair stands out. This is partially due to the complexity of the nervous anatomical system, its functioning and the inefficiency of conventional repair approaches, which are based on single components of either biomaterials or cells alone. Electrical stimulation has been shown to enhance the nerve regeneration process and this consequently makes the use of electrically conductive polymers very attractive for the construction of scaffolds for nerve tissue engineering. In this review, by taking into consideration the electrical properties of nerve cells and the effect of electrical stimulation on nerve cells, we discuss the most commonly utilized conductive polymers, polypyrrole (PPy) and polyaniline (PANI), along with their design and modifications, thus making them suitable scaffolds for nerve tissue engineering. Other electrospun, composite, conductive scaffolds, such as PANI/gelatin and PPy/poly(ε-caprolactone), with or without electrical stimulation, are also discussed. Different procedures of electrical stimulation which have been used in tissue engineering, with examples on their specific applications in tissue engineering, are also discussed.

  6. Preparation and characterization of electrical conductive PVA based materials for peripheral nerve tube-guides.

    PubMed

    Gonçalves, C; Ribeiro, J; Pereira, T; Luís, A L; Mauricio, A C; Santos, J D; Lopes, M A

    2016-08-01

    Peripheral nerve regeneration is a serious clinical problem. Presently, there are several nerve tube-guides available in the market, however with some limitations. The goal of this work was the development of a biomaterial with high electrical conductivity to produce tube-guides for nerve regeneration after neurotmesis injuries whenrver an end-to-end suture without tension is not possible. A matrix of poly(vinyl alcohol) (PVA) was used loaded with the following electrical conductive materials: COOH-functionalized multiwall carbon nanotubes (MWCNTs), poly(pyrrole) (PPy), magnesium chloride (MgCl2 ), and silver nitrate (AgNO3 ). The tube-guide production was carried out by a freezing/thawing process (physical crosslinking) with a final annealing treatment. After producing the tube-guide for nerve regeneration, the physicochemical characterization was performed. The most interesting results were achieved by loading PVA with 0.05% of PPy or COOH- functionalized CNTs. These tubes combined the electrical conductivity of carbon nanotubes (CNTs) and PPy with the biocompatibility of PVA matrix, with potential clinical application for nerve regeneration. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 1981-1987, 2016. PMID:27027727

  7. Morphological abnormalities of embryonic cranial nerves after in utero exposure to valproic acid: implications for the pathogenesis of autism with multiple developmental anomalies.

    PubMed

    Tashiro, Yasura; Oyabu, Akiko; Imura, Yoshio; Uchida, Atsuko; Narita, Naoko; Narita, Masaaki

    2011-06-01

    Autism is often associated with multiple developmental anomalies including asymmetric facial palsy. In order to establish the etiology of autism with facial palsy, research into developmental abnormalities of the peripheral facial nerves is necessary. In the present study, to investigate the development of peripheral cranial nerves for use in an animal model of autism, rat embryos were treated with valproic acid (VPA) in utero and their cranial nerves were visualized by immunostaining. Treatment with VPA after embryonic day 9 had a significant effect on the peripheral fibers of several cranial nerves. Following VPA treatment, immunoreactivity within the trigeminal, facial, glossopharyngeal and vagus nerves was significantly reduced. Additionally, abnormal axonal pathways were observed in the peripheral facial nerves. Thus, the morphology of several cranial nerves, including the facial nerve, can be affected by prenatal VPA exposure as early as E13. Our findings indicate that disruption of early facial nerve development is involved in the etiology of asymmetric facial palsy, and may suggest a link to the etiology of autism.

  8. Nerve conduction velocity in man during deep diving to 360 msw.

    PubMed

    Todnem, K; Knudsen, G; Riise, T; Nyland, H; Aarli, J A

    1989-01-01

    The function of the sensory and motor median nerves was examined in 6 divers during a simulated dive to 360 meters of seawater (msw), with a mixture of helium and oxygen (heliox) as breathing gas. Divers were examined in the compression chamber before the dive, at 360, 300, 240, 130, 50, and 5 msw, and with skin temperatures ranging from 29.2 degrees to 35.2 degrees C. Examinations were performed with superficial stimulating and recording electrodes. Fast sensory nerve conduction decreased with increase in hyperbaric pressure and with decrease in skin temperature. There was no significant correlation between slow sensory conduction and hyperbaric pressure. Distal motor latency increased with increase in hyperbaric pressure and with decrease in skin temperature. The effect of pressure was independent of temperature. No significant functional changes were detected in the main nerve trunk proximal to the wrist or in the F-wave responses.

  9. Effects of high-frequency alternating current on axonal conduction through the vagus nerve

    NASA Astrophysics Data System (ADS)

    Waataja, Jonathan J.; Tweden, Katherine S.; Honda, Christopher N.

    2011-10-01

    High-frequency alternating current (HFAC) is known to disrupt axonal conduction in peripheral nerves, and HFAC has much potential as a therapeutic approach for a number of pathological conditions. Many previous studies have utilized motor output as a bioassay of effects of HFAC on conduction through medium- to large-diameter motor axons. However, little is known about the effectiveness of HFAC on smaller, more slowly conducting nerve fibres. The present study tested whether HFAC influences axonal conduction through sub-diaphragmatic levels of the rat vagus nerve, which consists almost entirely of small calibre axons. Using an isolated nerve preparation, we tested the effects of HFAC on electrically evoked compound action potentials (CAPs). We found that delivery of charge-balanced HFAC at 5000 Hz for 1 min was effective in producing reversible blockade of axonal conduction. Both Aδ and C components of the vagus CAP were attenuated, and the degree of blockade as well as time to recovery was proportional to the amount of HFAC current delivered. The Aδ waves were more sensitive than C waves to HFAC blockade, but they required more time to recover.

  10. Effects of high-frequency alternating current on axonal conduction through the vagus nerve.

    PubMed

    Waataja, Jonathan J; Tweden, Katherine S; Honda, Christopher N

    2011-10-01

    High-frequency alternating current (HFAC) is known to disrupt axonal conduction in peripheral nerves, and HFAC has much potential as a therapeutic approach for a number of pathological conditions. Many previous studies have utilized motor output as a bioassay of effects of HFAC on conduction through medium- to large-diameter motor axons. However, little is known about the effectiveness of HFAC on smaller, more slowly conducting nerve fibres. The present study tested whether HFAC influences axonal conduction through sub-diaphragmatic levels of the rat vagus nerve, which consists almost entirely of small calibre axons. Using an isolated nerve preparation, we tested the effects of HFAC on electrically evoked compound action potentials (CAPs). We found that delivery of charge-balanced HFAC at 5000 Hz for 1 min was effective in producing reversible blockade of axonal conduction. Both Aδ and C components of the vagus CAP were attenuated, and the degree of blockade as well as time to recovery was proportional to the amount of HFAC current delivered. The Aδ waves were more sensitive than C waves to HFAC blockade, but they required more time to recover. PMID:21918293

  11. Confirmation of Correlation between Brain Nerve Conduction Velocity and Intelligence Level in Normal Adults

    ERIC Educational Resources Information Center

    Reed, T. Edward; Vernon, Philip A.; Johnson, Andrew M.

    2004-01-01

    In 1992, Reed and Jensen ["Intelligence" 16 (1992) 259-272] reported a positive correlation (0.26; "p"= 0.002; 0.37 after correcting for restricted intelligence range) between a brain nerve conduction velocity (NCV) and intelligence level in 147 normal male students. In the first follow-up of their study, we report on a study using similar NCV…

  12. Conduction Velocity in a Brain Nerve Pathway of Normal Adults Correlates with Intelligence Level.

    ERIC Educational Resources Information Center

    Reed, T. Edward; Jensen, Arthur R.

    1992-01-01

    A correlation between intelligence level (IQ) and nerve conduction velocity (NCV) was demonstrated for 147 undergraduate students in the eastern San Francisco (California) Bay area. Recent studies of retarded subjects support the findings, explainable by positive correlations among NCV, speed of information processing, and IQ. (Author/SLD)

  13. Peripheral Nerve Conduction Velocity, Reaction Time, and Intelligence: An Attempt to Replicate Vernon and Mori.

    ERIC Educational Resources Information Center

    Wickett, John C.; Vernon, Philip A.

    1994-01-01

    In a study involving 38 adult females, nerve conduction velocity (NCV) did not correlate with intelligence or reaction time. A reanalysis of the Vernon and Mori data showed a possible sex difference in relation to NCV and intelligence, with the correlation between these variables much smaller in females than males. (SLD)

  14. The Expanded Bead Size of Corneal C-Nerve Fibers Visualized by Corneal Confocal Microscopy Is Associated with Slow Conduction Velocity of the Peripheral Nerves in Patients with Type 2 Diabetes Mellitus.

    PubMed

    Ishibashi, Fukashi; Kojima, Rie; Taniguchi, Miki; Kosaka, Aiko; Uetake, Harumi; Tavakoli, Mitra

    2016-01-01

    This study aims to establish the corneal nerve fiber (CNF) morphological alterations in a large cohort of type 2 diabetic patients and to investigate the association between the bead size, a novel parameter representing composite of accumulated mitochondria, glycogen particles, and vesicles in CNF, and the neurophysiological dysfunctions of the peripheral nerves. 162 type 2 diabetic patients and 45 healthy control subjects were studied in detail with a battery of clinical and neurological examinations and corneal confocal microscopy. Compared with controls, patients had abnormal CNF parameters. In particular the patients had reduced density and length of CNF and beading frequency and increased bead size. Alterations in CNF parameters were significant even in patients without neuropathy. The HbA1c levels were tightly associated with the bead size, which was inversely related to the motor and sensory nerve conduction velocity (NCV) and to the distal latency period of the median nerve positively. The CNF density and length positively correlated with the NCV and amplitude. The hyperglycemia-induced expansion of beads in CNF might be a predictor of slow NCV in peripheral nerves in type 2 diabetic patients. PMID:27563679

  15. The Expanded Bead Size of Corneal C-Nerve Fibers Visualized by Corneal Confocal Microscopy Is Associated with Slow Conduction Velocity of the Peripheral Nerves in Patients with Type 2 Diabetes Mellitus

    PubMed Central

    2016-01-01

    This study aims to establish the corneal nerve fiber (CNF) morphological alterations in a large cohort of type 2 diabetic patients and to investigate the association between the bead size, a novel parameter representing composite of accumulated mitochondria, glycogen particles, and vesicles in CNF, and the neurophysiological dysfunctions of the peripheral nerves. 162 type 2 diabetic patients and 45 healthy control subjects were studied in detail with a battery of clinical and neurological examinations and corneal confocal microscopy. Compared with controls, patients had abnormal CNF parameters. In particular the patients had reduced density and length of CNF and beading frequency and increased bead size. Alterations in CNF parameters were significant even in patients without neuropathy. The HbA1c levels were tightly associated with the bead size, which was inversely related to the motor and sensory nerve conduction velocity (NCV) and to the distal latency period of the median nerve positively. The CNF density and length positively correlated with the NCV and amplitude. The hyperglycemia-induced expansion of beads in CNF might be a predictor of slow NCV in peripheral nerves in type 2 diabetic patients. PMID:27563679

  16. Essential fatty acids prevent slowed nerve conduction in streptozotocin diabetic rats.

    PubMed

    Julu, P O

    1988-01-01

    Rats were given streptozotocin to induce insulin-dependent diabetes or citrate buffer alone in two experiments. Initially, the effect of 5 wks of dietary gamma-linolenic acid (GLA) plus eicosapentaenoic acid (EPA) on cutaneous nerve conduction velocity (CV) was examined. CV was determined by direct stimulation and recording from saphenous nerve under urethane anesthesia. Secondly, a 5 weeks study of supplementing the diet with GLA, GLA and EPA, or hydrogenated coconut oil (HC) was done. In addition, motor nerve CV was determined by directly stimulating sciatic nerve and recording from gastrocnemius muscle. The acute diabetes led to weight loss, and elevated blood glucose and glycosylated hemoglobin levels. Essential fatty acid (EFA) supplementation had no effect on any of these measures of severity of diabetes. In diabetic rats without EFA supplementation, CV of the myelinated fibers fell by 19-21%, while those receiving both GLA and EPA had normal CV. In diabetic rats receiving GLA alone, CV fell by 5-7%, which was significantly less than those without EFA supplementation (p less than 0.01 for cutaneous, and p less than 0.001 for motor nerves).

  17. Fast-conducting mechanoreceptors contribute to withdrawal behavior in normal and nerve injured rats.

    PubMed

    Boada, M Danilo; Martin, Thomas J; Peters, Christopher M; Hayashida, Kenichiro; Harris, Michael H; Houle, Timothy T; Boyden, Edward S; Eisenach, James C; Ririe, Douglas G

    2014-12-01

    Fast-conducting myelinated high-threshold mechanoreceptors (AHTMR) are largely thought to transmit acute nociception from the periphery. However, their roles in normal withdrawal and in nerve injury-induced hyperalgesia are less well accepted. Modulation of this subpopulation of peripheral neurons would help define their roles in withdrawal behaviors. The optically active proton pump, ArchT, was placed in an adeno-associated virus-type 8 viral vector with the CAG promoter and was administered by intrathecal injection resulting in expression in myelinated neurons. Optical inhibition of peripheral neurons at the soma and transcutaneously was possible in the neurons expressing ArchT, but not in neurons from control animals. Receptive field characteristics and electrophysiology determined that inhibition was neuronal subtype-specific with only AHTMR neurons being inhibited. One week after nerve injury the AHTMR are hyperexcitable, but can still be inhibited at the soma and transcutaneously. Withdrawal thresholds to mechanical stimuli in normal and in hyperalgesic nerve-injured animals also were increased by transcutaneous light to the affected hindpaw. This suggests that AHTMR neurons play a role not only in threshold-related withdrawal behavior in the normal animal, but also in sensitized states after nerve injury. This is the first time this subpopulation of neurons has been reversibly modulated to test their contribution to withdrawal-related behaviors before and after nerve injury. This technique may prove useful to define the role of selective neuronal populations in different pain states.

  18. Molecular Regulators of Nerve Conduction - Lessons from Inherited Neuropathies and Rodent Genetic Models

    PubMed Central

    Li, Jun

    2015-01-01

    Myelinated nerve fibers are highly compartmentalized. Helically wrapped lipoprotein membranes of myelin are integrated with subsets of proteins specifically in each compartment to shape the physiological behavior of these nerve fibers. With the advance of molecular biology and genetics, many functions of these proteins have been revealed over the past decade. In this review, we will first discuss how action potential propagation has been understood by classical electrophysiological studies. In particular, the discussion will be concentrated on how the geometric dimensions of myelinated nerve fibers (such as internodal length and myelin thickness) may affect nerve conduction velocity. This discussion will then extend into how specific myelin proteins may shape these geometric parameters, thereby regulating action potential propagation. For instance, periaxin may specifically affect the internodal length, but not other parameters. In contrast, neuregulin-1 may affect myelin thickness, but not axon diameter or internodal length. Finally, we will discuss how these basic neurobiological observations can be applied to inherited peripheral nerve diseases. PMID:25792482

  19. Conduction time for a 6-cm segment of the ulnar nerve across the elbow: reference values for the 6-cm conduction time test.

    PubMed

    Landau, Mark E; Campbell, William W

    2009-06-01

    Current electrodiagnostic studies for Ulnar nerve mononeuropathy at the elbow have substandard sensitivity and specificity. Reference values for a novel, screening electrodiagnostic test for ulnar nerve mononeuropathy at the elbow were obtained bilaterally from 72 subjects without any upper extremity signs or symptoms. The test used two, 3-cm straight line distances, one proximal, and one distal to the medial epicondyle to avoid a curvilinear measurement. The mean conduction times (CTE) were 1.16 +/- 0.16 milliseconds, 1.23 +/- 0.18 milliseconds, 1.33 +/- 0.24 milliseconds, for subjects 20 to 40, 40 to 60, and >60 years old, respectively. A CTE >1.50 milliseconds, >1.60 milliseconds, and >1.80 milliseconds for each age group would be considered abnormal conferring 98% specificity. The median side-to-side difference of CTE (CTE-diff) was 0.10 milliseconds with a range of 0.00 to 0.55 milliseconds. A CTE-diff >0.45 milliseconds has a specificity of 97%. Potential advantages to this method include straight-line measurement distances to reduce experimental error, and a distance less than 10 cm to improve lesion detection.

  20. Association between chronic exposure to arsenic and slow nerve conduction velocity among adolescents in Taiwan.

    PubMed

    Tseng, Hung-Pin; Wang, Yuan-Hung; Wu, Meei-Maan; The, Hee-Wen; Chiou, Hung-Yi; Chen, Chien-Jen

    2006-06-01

    The association between chronic exposure to arsenic and peripheral neuropathy has been controversial in previous studies, which may be due to the influence of factors, such as age, gender, chronic diseases, occupational injuries, and arsenic exposure. To clarify the question of this association, a cross-sectional study was designed. In total, 130 junior high school students aged 12-14 years were included and examined for the motor and sensory nerve conduction velocity of peripheral nerves in their right-upper and lower limbs. Concentrations of arsenic in well-water and history of drinking well-water were retrieved from a baseline database created in 1991. After adjustment for gender and height, a significant odds ratio of 2.9 (95% confidence interval [CI] 1.1-7.5) was observed for the development of slow nerve conduction velocity of the sural sensory action potential (SAP) among the study subjects with a cumulative arsenic dosage of>100.0 mg. In addition, a borderline statistical significance with odds ratio of 7.8 (95% CI 1.001-69.5) for the development of slow nerve conduction velocity of sural SAP was also observed among the study subjects who drank well-water containing arsenic concentrations of >50.0 microg/L and with a cumulative arsenic dosage of >100.0 mg. The study found that chronic exposure to arsenic might induce peripheral neuropathy. It also found that the slowing of the nerve conduction velocity of sural SAP might be an early marker of chronic arsenic neuropathy.

  1. Association of Long-Term Air Pollution with Ventricular Conduction and Repolarization Abnormalities

    PubMed Central

    Van Hee, Victor C; Szpiro, Adam A; Prineas, Ronald; Neyer, Jonathan; Watson, Karol; Siscovick, David; Park, Sung Kyun; Kaufman, Joel D

    2011-01-01

    Background Short-term exposure to air pollution may affect ventricular repolarization, but there is limited information on how long-term exposures might affect the surface ventricular electrocardiographic (ECG) abnormalities associated with cardiovascular events. We carried out a study to determine whether long-term air pollution exposure is associated with abnormalities of ventricular repolarization and conduction in adults without known cardiovascular disease. Methods A total of 4783 participants free of clinical cardiovascular disease in the Multi-Ethnic Study of Atherosclerosis underwent 12-lead ECG examinations, cardiac-computed tomography and calcium scoring, as well as estimation of air pollution exposure using a finely resolved spatio-temporal model to determine long-term average individual exposure to fine particulate matter (PM2.5) and proximity to major roadways. We assessed ventricular electrical abnormalities including presence of QT prolongation (Rautaharju QTrr criteria) and intraventricular conduction delay (QRS duration > 120 msec). We used logistic regression to determine the adjusted relationship between air pollution exposures and ECG abnormalities. Results A 10 µg/m3-increase in estimated residential PM2.5 was associated with an increased odds of prevalent QT prolongation (adjusted odds ratio [OR]= 1.6 [95% confidence interval (CI)= 1.2 to 2.2]) and intraventricular conduction delay (OR 1.7, 95% CI: 1.0 to 2.6, independent of coronary-artery calcium score. Living near major roadways was not associated with ventricular electrical abnormalities. No significant evidence of effect modification by traditional risk factors or study site was observed. Conclusions This study demonstrates an association between long-term exposure to air pollution and ventricular repolarization and conduction abnormalities in adults without clinical cardiovascular disease, independent of subclinical coronary arterial calcification. PMID:21918454

  2. A mouse model of conduction system patterning abnormalities in heterotaxy syndrome.

    PubMed

    Czosek, Richard J; Haaning, Allison; Ware, Stephanie M

    2010-10-01

    Duplication or absence of parts of the specialized cardiac conduction system in patients with heterotaxy syndrome causes significant clinical disease, but the mechanistic basis by which embryonic disruption of left-right patterning alters conduction system patterning in these patients is not well understood. We sought to determine whether a mouse model of X-linked human heterotaxy recapitulates conduction system abnormalities identified in patients with heterotaxy. Cardiac structure and conduction system patterning were evaluated in Zic3 null embryos from e9.5 to e16.5 using genetic and molecular methods. Severe structural abnormalities involving atrial, ventricular, and conotruncal development were associated with a spectrum of disorganized and ambiguous arrangements throughout the conduction system, including the appearance of duplicated structures. The severity and location of conduction system abnormalities correlated with the severity and location of associated structural heart disease and were identifiable at the earliest stages examined. The Zic3 mouse model provides a novel tool to dissect the mechanistic underpinnings of conduction system patterning and dysfunction and its relationship to cardiovascular malformations, making it a promising model to improve understanding and risk assessment in the clinical arena.

  3. [Nerve conduction velocity of repeater F-waves is identical to that of M-waves].

    PubMed

    Hasegawa, O; Matsumoto, S; Gondo, G; Arita, T; Iwasawa, H

    2001-12-01

    F-wave normally varies in latency and waveform from one response to the next. But the number of identical responses in a series of F-waves may be increased with neurogenic atrophy consistent with a decreased number of motoneurons capable of responding to antidromic stimulation. They are called "repeater F-waves". We herein demonstrate some repeater F-waves observed in three patients with moderate or slight diabetic polyneuropathy. In their motor nerve conduction studies on the peroneal nerve the maximum conduction velocity was 33 m/sec in patient 1, 36 m/sec in patient 2 and 48 m/sec in patient 3. A total of 6 delayed indirect potentials were repeatedly evoked after nerve trunk stimulation. They fulfilled the characteristics of F-wave. Their conduction velocities in the leg segment were 27, 26, 23 m/sec in patient 1, 34, 33 m/sec in patient 2 and 46 m/sec in patient 3. Repeater F-waves are occasionally observed in patients with amyotrophic lateral sclerosis, cervical spondylosis or entrapment neuropathies, in which the number of motoneuron is decreased. In diabetic polyneuropathy some repeater F-waves were also observed in patients not only with moderate to severe neuropathy but also with normal nerve conduction. F-waves are generated by an antidromic backfiring of motor neurons, and they occur preferentially in large motor neurons. Larger motor neurons inhibit smaller axons through the activation of Renshaw cells. In our 3 patients conduction velocities of the repeated F-waves were all identical to the main component of M-wave. These observations reconfirmed the hypothesis that relatively large motor neurons generating F-waves are preferentially activated also in repeater F-waves.

  4. Reversible nerve conduction block in patients with polyneuropathy after ultrasound thermotherapy at therapeutic dosage.

    PubMed

    Hong, C Z

    1991-02-01

    This study investigated the effect of ultrasound on nerve conduction in patients with polyneuropathy. Eight able-bodied controls (Group C) and 16 patients with clinical and physiologic evidence of polyneuropathy were tested. Eight patients (Group NP) had no aching pain symptoms; eight patients (Group P) had severe aching pain, burning sensation, unpleasant tingling, and/or hyperesthesia in the lower extremities. For two minutes, therapeutic ultrasound in doses of 0.5, 1.0, and 1.5W/cm2 were applied over the anterior surface of the leg along the pathway of the deep peroneal nerve. Peroneal nerve conduction studies were performed before, during, and after ultrasound treatment. The compound muscle action potential (CMAP) was recorded from the extensor digitorum brevis muscle. Nerve conduction studies on all eight patients in Group P revealed a significant decrease (41.4% and 44% reduced for doses of 1.0W/cm2 and 1.5W/cm2, respectively; p less than .05) in amplitude of CMAP (from baseline to the first negative peak), and an increase (6.4% and 6.7% increased for doses of 1.0W/cm2 and 1.5W/cm2, respectively; p less than .05) in proximal latency one minute after ultrasound application with a dose of 1.0 or 1.5W/cm2, but not with a dose of 0.5W/cm2 (p greater than 0.1). Changes returned to pretreatment values within five minutes of cessation of ultrasound therapy. In Groups C and NP, there were no significant changes in amplitudes of CMAP or proximal latency before, during, or after ultrasound therapy at a dose of 0.5, 1.0, or 1.5W/cm2. It was concluded that ultrasonic therapy with therapeutic dosage may cause a reversible conduction block on patients with painful polyneuropathy.

  5. Effect of myelination on the conduction velocity of optic nerve fibres.

    PubMed

    Tolhurst, D J; Lewis, P R

    1992-04-01

    It was proposed by Rushton in 1951, from theoretical considerations, that myelinated fibres less than 1 micron in diameter would conduct more slowly than unmyelinated fibres of the same size and that myelinated fibres below about 0.7 micron would not conduct at all. The experimental data on which he based his theory are all from the peripheral nervous system where small myelinated fibres are rare, and no experimental verification of Rushton's hypothesis has been attempted. In mammalian optic nerve, nearly all the fibres are myelinated; yet half have diameters below 1 micron, with many below 0.7 micron. The many studies of conduction velocities in the visual system enable a test of Rushton's hypothesis to be made. We have examined the correlations between conduction velocity and fibre diameter from a wide range of published studies of the mammalian visual system. The results of our analysis suggest that the small myelinated fibres of the optic nerve and optic tract conduct action potentials more rapidly than is predicted by Rushton's hypothesis, while the unmyelinated axons within the retina actually conduct more slowly than predicted. There is no reason to believe, in this case, that myelination of a small axon will reduce its conduction velocity.

  6. Changes in nerve conduction and Pi/PCr ratio during denervation-reinnervation of the gastrocsoleus muscles of rats

    NASA Technical Reports Server (NTRS)

    Lai, K. S.; Jaweed, M. M.; Seestead, R.; Herbison, G. J.; Ditunno, J. F. Jr; McCully, K.; Chance, B.

    1992-01-01

    The purpose of this investigation was to study the changes in nerve conduction and phosphate metabolites of the gastrocsoleus muscles of rats during denervation-reinnervation. Sixteen male Sprague-Dawley rats underwent unilateral crush-denervation of the left sciatic nerves at the sciatic notch. Six rats were used for measurement of motor conduction latency and action potential amplitude of the gastrocsoleus muscle by stimulating the sciatic nerve at one, two and eight weeks after nerve crush. The other ten rats were designated for evaluation of the ratio of inorganic phosphorous (Pi) to phosphocreatine (PCr) by a 31P-phosphoenergetic spectrometer at two weeks and eight weeks after nerve crush. None of the sciatic nerves showed conduction to the gastrocsoleus at one or two weeks after nerve crush. At eight weeks postcrush, the motor conduction latency returned to within normal limits, whereas the action potential amplitude was only 55% of the normal. For the eight-week period of study, the Pi/PCr ratio of the normal control muscles ranged between 0.09 +/- 0.02 and 0.11 +/- 0.02 (mean +/- SD). The denervated muscles showed an increase of Pi/PCr ratio by 54% at two weeks postcrush, compared to the respective contralateral control sides. The ratios returned to the normal value by eight weeks postcrush. In summary, these data suggested that the metabolic recovery of the crush-denervated muscle followed the same pattern as the parameters of nerve conduction.

  7. Anomalies of cardiac venous drainage associated with abnormalities of cardiac conduction system.

    PubMed

    Morgan, D R; Hanratty, C G; Dixon, L J; Trimble, M; O'Keeffe, D B

    2002-07-01

    The embryological development of the superior vena cava (SVC) is complex. If the left common cardinal vein fails to occlude it can, along with the left duct of Cuvier form a left SVC, which frequently drains into the coronary sinus. This may result in abnormalities in the anatomy of this structure. A persistent left SVC occurs in 0.5% of the normal population, and 3% to 4.3% of patients with congenital heart anomalies. The pacemaking tissue of the heart is derived from two sites near the progenitors of the superior vena cava. The right-sided site forms the sinoatrial node, the left-sided site is normally carried down to an area near the coronary sinus. Out of 300 patients with cardiac rhythm abnormalities, who have undergone electrophysiological studies (EPS), or permanent pacemaker insertion (PPI), we identified 12 patients with cardiac conduction abnormalities and anomalies of venous drainage. Anomalies of the coronary sinus may be associated with abnormalities of the conduction system of the heart. This may be due to the close proximity of the coronary sinus to the final position of the left-sided primitive pacemaking tissue. In our series of 300 patients, 4% had an associated left SVC, a similar incidence to that found in previous studies of congenital heart disease.

  8. Carboxylic Acid-Functionalized Conducting-Polymer Nanotubes as Highly Sensitive Nerve-Agent Chemiresistors.

    PubMed

    Kwon, Oh Seok; Park, Chul Soon; Park, Seon Joo; Noh, Seonmyeong; Kim, Saerona; Kong, Hye Jeong; Bae, Joonwon; Lee, Chang-Soo; Yoon, Hyeonseok

    2016-09-21

    Organophosphates are powerful inhibitors of acetylcholinesterase, which is critical to nerve function. Despite continuous research for detecting the highly toxic organophosphates, a new and improved methodology is still needed. Herein we demonstrate simple-to-fabricate chemiresistive gas sensors using conducting-polymer polypyrrole (PPy) nanotube transducers, which are chemically specific and capable of recognizing sub-ppb concentrations (ca. 0.5 ppb) of dimethyl methylphosphonate (DMMP), a simulant of nerve agent sarin. Interestingly, the introduction of carboxylic groups on the surface of PPy nanotube transistors resulted in enhanced sensitivity to DMMP via intermolecular hydrogen bonding. Furthermore, it was found that the sensitivity of the nanotube transducer depended on the degree of the carboxylic group introduced. Finally, a sensor array composed of 5 different transducers including the carboxylated nanotubes exhibited excellent selectivity to DMMP in 16 vapor species.

  9. Carboxylic Acid-Functionalized Conducting-Polymer Nanotubes as Highly Sensitive Nerve-Agent Chemiresistors

    PubMed Central

    Kwon, Oh Seok; Park, Chul Soon; Park, Seon Joo; Noh, Seonmyeong; Kim, Saerona; Kong, Hye Jeong; Bae, Joonwon; Lee, Chang-Soo; Yoon, Hyeonseok

    2016-01-01

    Organophosphates are powerful inhibitors of acetylcholinesterase, which is critical to nerve function. Despite continuous research for detecting the highly toxic organophosphates, a new and improved methodology is still needed. Herein we demonstrate simple-to-fabricate chemiresistive gas sensors using conducting-polymer polypyrrole (PPy) nanotube transducers, which are chemically specific and capable of recognizing sub-ppb concentrations (ca. 0.5 ppb) of dimethyl methylphosphonate (DMMP), a simulant of nerve agent sarin. Interestingly, the introduction of carboxylic groups on the surface of PPy nanotube transistors resulted in enhanced sensitivity to DMMP via intermolecular hydrogen bonding. Furthermore, it was found that the sensitivity of the nanotube transducer depended on the degree of the carboxylic group introduced. Finally, a sensor array composed of 5 different transducers including the carboxylated nanotubes exhibited excellent selectivity to DMMP in 16 vapor species. PMID:27650635

  10. Carboxylic Acid-Functionalized Conducting-Polymer Nanotubes as Highly Sensitive Nerve-Agent Chemiresistors.

    PubMed

    Kwon, Oh Seok; Park, Chul Soon; Park, Seon Joo; Noh, Seonmyeong; Kim, Saerona; Kong, Hye Jeong; Bae, Joonwon; Lee, Chang-Soo; Yoon, Hyeonseok

    2016-01-01

    Organophosphates are powerful inhibitors of acetylcholinesterase, which is critical to nerve function. Despite continuous research for detecting the highly toxic organophosphates, a new and improved methodology is still needed. Herein we demonstrate simple-to-fabricate chemiresistive gas sensors using conducting-polymer polypyrrole (PPy) nanotube transducers, which are chemically specific and capable of recognizing sub-ppb concentrations (ca. 0.5 ppb) of dimethyl methylphosphonate (DMMP), a simulant of nerve agent sarin. Interestingly, the introduction of carboxylic groups on the surface of PPy nanotube transistors resulted in enhanced sensitivity to DMMP via intermolecular hydrogen bonding. Furthermore, it was found that the sensitivity of the nanotube transducer depended on the degree of the carboxylic group introduced. Finally, a sensor array composed of 5 different transducers including the carboxylated nanotubes exhibited excellent selectivity to DMMP in 16 vapor species. PMID:27650635

  11. Post stimulus effects of high frequency biphasic electrical current on a fibre's conductibility in isolated frog nerves

    NASA Astrophysics Data System (ADS)

    Liu, Hailong; Zhu, Linlin; Sheng, Shulei; Sun, Lifei; Zhou, Hongmin; Tang, Hong; Qiu, Tianshuang

    2013-06-01

    Objective. High frequency biphasic (HFB) electrical currents are widely used in nerve blocking studies. Their safety margins largely remain unknown and need to be investigated. Approach. This study, exploring the post stimulus effects of HFB electrical currents on a nerve's conductibility, was performed on bullfrog sciatic nerves. Both compound action potentials (CAPs) and differential CAPs (DCAPs, i.e. control CAPs subtracted by CAPs following HFB currents) were obtained, and N1 and N2 components, which were the first and second upward components of DCAPs, were used for analyses of the effects introduced by HFB electrical stimulation. Main results. First, HFB currents of 10 kHz at a completely blocking threshold were applied for 5 s. The maximum amplitudes and conducting velocities of the CAPs were significantly (P < 0.02) decreased within the observed period (60 s) following HFB currents. The DCAPs displayed clear N1 and N2 components, demonstrating respectively the losses of the fibres' normal conductibility and the appearances of new delayed conductions. Decreases of N1 amplitudes along time, regarded as the recovery of the nerve's conductibility, exhibited two distinct phases: a fast one lasting several seconds and a slow one lasting longer than 5 min. Further tests showed a linear relationship between the HFB stimulation durations and recovering periods of N1 amplitudes. Supra-threshold blocking did not cause higher N1 amplitudes. Significance. This study indicates that HFB electrical currents lead to long lasting post stimulus reduction of a nerve's conductibility, which might relate to potential nerve injuries. A possible mechanism, focusing on changes in intracellular and periaxonal ionic concentrations, was proposed to underlie the reduction of the nerve's conductibility and potential nerve injuries. Greater caution and stimulation protocols with greater safety margins should be explored when utilizing HFB electrical current to block nerve conductions.

  12. The effect of cryotherapy on nerve conduction velocity, pain threshold and pain tolerance

    PubMed Central

    Algafly, Amin A; George, Keith P

    2007-01-01

    Objectives To determine the impact of the application of cryotherapy on nerve conduction velocity (NCV), pain threshold (PTH) and pain tolerance (PTO). Design A within‐subject experimental design; treatment ankle (cryotherapy) and control ankle (no cryotherapy). Setting Hospital‐based physiotherapy laboratory. Participants A convenience sample of adult male sports players (n = 23). Main outcome measures NCV of the tibial nerve via electromyogram as well as PTH and PTO via pressure algometer. All outcome measures were assessed at two sites served by the tibial nerve: one receiving cryotherapy and one not receiving cryotherapy. Results In the control ankle, NCV, PTH and PTO did not alter when reassessed. In the ankle receiving cryotherapy, NCV was significantly and progressively reduced as ankle skin temperature was reduced to 10°C by a cumulative total of 32.8% (p<0.05). Cryotherapy led to an increased PTH and PTO at both assessment sites (p<0.05). The changes in PTH (89% and 71%) and PTO (76% and 56%) were not different between the iced and non‐iced sites. Conclusions The data suggest that cryotherapy can increase PTH and PTO at the ankle and this was associated with a significant decrease in NCV. Reduced NCV at the ankle may be a mechanism by which cryotherapy achieves its clinical goals. PMID:17224445

  13. Topological Defects at the Graphene/h-BN interface Abnormally Enhance Its Thermal Conductance.

    PubMed

    Liu, Xiangjun; Zhang, Gang; Zhang, Yong-Wei

    2016-08-10

    Low thermal conductance across interface is often the limiting factor in managing heat in many advanced device applications. The most commonly used approach to enhance the thermal conductance is to reduce/eliminate the interfacial structural defects. Using a graphene/h-BN (Gr/h-BN) interface, we show surprisingly that topological defects are able to enhance the thermal conductance across the interface. It is found that the phonon transmission across the Gr/h-BN interface with 5|7 defects is higher than that of the pristine interface, which is in strong contrast to the common notion that interface defects promote phonon scattering. By analyzing the strain distribution and phonon vibrational spectra, we find that this abnormal enhancement in interfacial thermal conductance originates from the localization of the stress fields arising from misfit dislocations and their out-of-plane deformations at the interface. In the presence of the defects, the overall mismatch strain is reduced. In addition, the out-of-plane deformations screen the long-ranged dislocation strain fields, resulting in the stress fields to be localized only at the cores of the defects. This abnormal mechanism provides a new dimension to enhance the interfacial thermal conductance in two-dimensional heterostructures.

  14. Topological Defects at the Graphene/h-BN interface Abnormally Enhance Its Thermal Conductance.

    PubMed

    Liu, Xiangjun; Zhang, Gang; Zhang, Yong-Wei

    2016-08-10

    Low thermal conductance across interface is often the limiting factor in managing heat in many advanced device applications. The most commonly used approach to enhance the thermal conductance is to reduce/eliminate the interfacial structural defects. Using a graphene/h-BN (Gr/h-BN) interface, we show surprisingly that topological defects are able to enhance the thermal conductance across the interface. It is found that the phonon transmission across the Gr/h-BN interface with 5|7 defects is higher than that of the pristine interface, which is in strong contrast to the common notion that interface defects promote phonon scattering. By analyzing the strain distribution and phonon vibrational spectra, we find that this abnormal enhancement in interfacial thermal conductance originates from the localization of the stress fields arising from misfit dislocations and their out-of-plane deformations at the interface. In the presence of the defects, the overall mismatch strain is reduced. In addition, the out-of-plane deformations screen the long-ranged dislocation strain fields, resulting in the stress fields to be localized only at the cores of the defects. This abnormal mechanism provides a new dimension to enhance the interfacial thermal conductance in two-dimensional heterostructures. PMID:27387848

  15. Protein-releasing conductive anodized alumina membranes for nerve-interface materials.

    PubMed

    Altuntas, Sevde; Buyukserin, Fatih; Haider, Ali; Altinok, Buket; Biyikli, Necmi; Aslim, Belma

    2016-10-01

    Nanoporous anodized alumina membranes (AAMs) have numerous biomedical applications spanning from biosensors to controlled drug delivery and implant coatings. Although the use of AAM as an alternative bone implant surface has been successful, its potential as a neural implant coating remains unclear. Here, we introduce conductive and nerve growth factor-releasing AAM substrates that not only provide the native nanoporous morphology for cell adhesion, but also induce neural differentiation. We recently reported the fabrication of such conductive membranes by coating AAMs with a thin C layer. In this study, we investigated the influence of electrical stimulus, surface topography, and chemistry on cell adhesion, neurite extension, and density by using PC 12 pheochromocytoma cells in a custom-made glass microwell setup. The conductive AAMs showed enhanced neurite extension and generation with the electrical stimulus, but cell adhesion on these substrates was poorer compared to the naked AAMs. The latter nanoporous material presents chemical and topographical features for superior neuronal cell adhesion, but, more importantly, when loaded with nerve growth factor, it can provide neurite extension similar to an electrically stimulated CAAM counterpart. PMID:27287158

  16. Easy method to examine single nerve fiber excitability and conduction parameters using intact nonanesthetized earthworms.

    PubMed

    Bähring, Robert; Bauer, Christiane K

    2014-09-01

    The generation and conduction of neuronal action potentials (APs) were the subjects of a cell physiology exercise for first-year medical students. In this activity, students demonstrated the all-or-none nature of AP generation, measured conduction velocity, and examined the dependence of the threshold stimulus amplitude on stimulus duration. For this purpose, they used the median giant nerve fiber (MGF) in the ventral nerve cord of the common earthworm (Lumbricus terrestris). Here, we introduce a specialized stimulation and recording chamber that the nonanesthetized earthworm enters completely unforced. The worm resides in a narrow round duct with silver electrodes on the bottom such that individual APs of the MGF can be elicited and recorded superficially. Our experimental setup combines several advantages: it allows noninvasive single fiber AP measurements taken from a nonanesthetized animal that is yet restrained. Students performed the experiments with a high success rate. According to the data acquired by the students, the mean conduction velocity of the MGF was 30.2 m/s. From the amplitude-duration relationship for threshold stimulation, rheobase and chronaxie were graphically determined by the students according to Lapicque's method. The mean rheobase was 1.01 V, and the mean chronaxie was 0.06 ms. The acquired data and analysis results are of high quality, as deduced from critical examination based on the law of Weiss. In addition, we provide video material, which was also used in the practical course. PMID:25179616

  17. Protein-releasing conductive anodized alumina membranes for nerve-interface materials.

    PubMed

    Altuntas, Sevde; Buyukserin, Fatih; Haider, Ali; Altinok, Buket; Biyikli, Necmi; Aslim, Belma

    2016-10-01

    Nanoporous anodized alumina membranes (AAMs) have numerous biomedical applications spanning from biosensors to controlled drug delivery and implant coatings. Although the use of AAM as an alternative bone implant surface has been successful, its potential as a neural implant coating remains unclear. Here, we introduce conductive and nerve growth factor-releasing AAM substrates that not only provide the native nanoporous morphology for cell adhesion, but also induce neural differentiation. We recently reported the fabrication of such conductive membranes by coating AAMs with a thin C layer. In this study, we investigated the influence of electrical stimulus, surface topography, and chemistry on cell adhesion, neurite extension, and density by using PC 12 pheochromocytoma cells in a custom-made glass microwell setup. The conductive AAMs showed enhanced neurite extension and generation with the electrical stimulus, but cell adhesion on these substrates was poorer compared to the naked AAMs. The latter nanoporous material presents chemical and topographical features for superior neuronal cell adhesion, but, more importantly, when loaded with nerve growth factor, it can provide neurite extension similar to an electrically stimulated CAAM counterpart.

  18. Easy method to examine single nerve fiber excitability and conduction parameters using intact nonanesthetized earthworms

    PubMed Central

    Bauer, Christiane K.

    2014-01-01

    The generation and conduction of neuronal action potentials (APs) were the subjects of a cell physiology exercise for first-year medical students. In this activity, students demonstrated the all-or-none nature of AP generation, measured conduction velocity, and examined the dependence of the threshold stimulus amplitude on stimulus duration. For this purpose, they used the median giant nerve fiber (MGF) in the ventral nerve cord of the common earthworm (Lumbricus terrestris). Here, we introduce a specialized stimulation and recording chamber that the nonanesthetized earthworm enters completely unforced. The worm resides in a narrow round duct with silver electrodes on the bottom such that individual APs of the MGF can be elicited and recorded superficially. Our experimental setup combines several advantages: it allows noninvasive single fiber AP measurements taken from a nonanesthetized animal that is yet restrained. Students performed the experiments with a high success rate. According to the data acquired by the students, the mean conduction velocity of the MGF was 30.2 m/s. From the amplitude-duration relationship for threshold stimulation, rheobase and chronaxie were graphically determined by the students according to Lapicque's method. The mean rheobase was 1.01 V, and the mean chronaxie was 0.06 ms. The acquired data and analysis results are of high quality, as deduced from critical examination based on the law of Weiss. In addition, we provide video material, which was also used in the practical course. PMID:25179616

  19. Persistent reduction of conduction velocity and myelinated axon damage in vibrated rat tail nerves.

    PubMed

    Loffredo, Michael A; Yan, Ji-Geng; Kao, Dennis; Zhang, Lin Ling; Matloub, Hani S; Riley, Danny A

    2009-06-01

    Prolonged hand-transmitted vibration exposure in the workplace has been recognized for almost a century to cause neurodegenerative and vasospastic disease. Persistence of the diseased state for years after cessation of tool use is of grave concern. To understand persistence of vibration injury, the present study examined recovery of nerve conduction velocity and structural damage of myelinated axons in a rat tail vibration model. Both 7 and 14 days of vibration (4 h/day) decreased conduction velocity. The decrease correlated directly with the increased percentage of disrupted myelinated axons. The total number of myelinated axons was unchanged. During 2 months of recovery, conduction velocity returned to control level after 7-day vibration but remained decreased after 14-day vibration. The rat tail model provides insight into understanding the persistence of neural deficits in hand-arm vibration syndrome.

  20. Gallic acid and exercise training improve motor function, nerve conduction velocity but not pain sense reflex after experimental sciatic nerve crush in male rats

    PubMed Central

    Hajimoradi, Maryam; Fazilati, Mohammad; Gharib-Naseri, Mohammad Kazem; Sarkaki, Alireza

    2015-01-01

    Objective: The aim of present study was to evaluate the effects of oral administration of gallic acid (GA) for 21 days alone and in combination with exercise on nerve conduction velocity and sensory and motor functions in rats with sciatic nerve crush. Materials and Methods: Seventy adult male Wistar rats (250-300 g) were divided randomly into 7 groups with 10 in each: 1) Control (Cont), 2) Crushed + Vehicle (Cr +Veh), 3-5) Crushed + gallic acid (Cr+GA) (50, 100, and 200 mg/kg/2 mL, orally), 6) Crushed + exercise (Cr+Exe), and 7) Crushed + exercise + effective dose of gallic acid (Cr+Exe +GA200) for 21 days. In order to establish an animal model of sciatic nerve crush, equivalent to 7 kg of force pressed on 2-3 mm of sciatic nerve for 30 s, three times with 30 s intervals. Pain sense reflex in hot plate, motor coordination in rotarod, and sciatic nerve conduction velocity (SNCV) in all groups were tested. Data were analyzed using one-way ANOVA followed by Tukey’s post hoc test and p<0.05 has assigned as the significant difference. Results: Pain threshold was increased significantly in untreated crushed rats while motor function and SNCV were decreased in all groups with nerve crush (p<0.05, p<0.01, p<0.001 vs. control). Pain reflex latency was not changed in treated groups. Motor coordination and SNCV were improved in groups Cr+GA200 and Cr+Exe + GA200 (p<0.05, p<0.01 vs. Cr+Veh). Conclusion: GA, dose-dependently, may have therapeutic potential to improve the peripheral nerve degeneration, which is most likely related, at least in part, to its antioxidant and therapeutic properties. PMID:26445710

  1. Development of Electrically Conductive Oligo(polyethylene Glycol) Fumarate-Polypyrrole Hydrogels for Nerve Regeneration

    PubMed Central

    Runge, M. Brett; Dadsetan, Mahrokh; Baltrusaitis, Jonas; Ruesink, Terry; Lu, Lichun; Windebank, Anthony J.; Yaszemski, Michael J.

    2014-01-01

    Electrically conductive hydrogel composites consisting of oligo(polyethylene glycol) fumarate (OPF) and polypyrrole (PPy) were developed for applications in nerve regeneration. OPF-PPy scaffolds were synthesized using three different anions: naphthalene-2-sulfonic acid sodium salt (NSA), dodecylbenzenesulfonic acid sodium salt (DBSA), and dioctyl sulfosuccinate sodium salt (DOSS). Scaffolds were characterized by ATR-FTIR, XPS, AFM, dynamic mechanical analysis, electrical resistivity measurements, and swelling experiments. OPF-PPy scaffolds were shown to consist of up to 25 mol% polypyrrole with a compressive modulus ranging from 265 to 323 kPa and a sheet resistance ranging from 6 to 30 × 103 Ohms/square. In vitro studies using PC12 cells showed OPF-PPy materials had no cytotoxicity and PC12 cells showed distinctly better cell attachment and an increase in the percent of neurite bearing cells on OPF-PPy materials compared to OPF. The neurite lengths of PC12 cells were significantly higher on OPF-PPyNSA and OPF-PPyDBSA. These results show that electrically conductive OPF-PPy hydrogels are promising candidates for future applications in nerve regeneration. PMID:20942380

  2. Nerve Growth Factor-Immobilized Electrically Conducting Fibrous Scaffolds for Potential Use in Neural Engineering Applications

    PubMed Central

    Lee, Jae Y.; Bashur, Chris A.; Milroy, Craig A.; Forciniti, Leandro; Goldstein, Aaron S.

    2015-01-01

    Engineered scaffolds simultaneously exhibiting multiple cues are highly desirable for neural tissue regeneration. To this end, we developed a neural tissue engineering scaffold that displays submicrometer-scale features, electrical conductivity, and neurotrophic activity. Specifically, electrospun poly(lactic acid-co-glycolic acid) (PLGA) nanofibers were layered with a nanometer thick coating of electrically conducting polypyrrole (PPy) presenting carboxylic groups. Then, nerve growth factor (NGF) was chemically immobilized onto the surface of the fibers. These NGF-immobilized PPy-coated PLGA (NGF-PPyPLGA) fibers supported PC12 neurite formation (28.0±3.0% of the cells) and neurite outgrowth (14.2 µm median length), which were comparable to that observed with NGF (50 ng/mL) in culture medium (29.0±1.3%, 14.4 µm). Electrical stimulation of PC12 cells on NGF-immobilized PPyPLGA fiber scaffolds was found to further improve neurite development and neurite length by 18% and 17%, respectively, compared to unstimulated cells on the NGF-immobilized fibers. Hence, submicrometer-scale fibrous scaffolds that incorporate neurotrophic and electroconducting activities may serve as promising neural tissue engineering scaffolds such as nerve guidance conduits. PMID:21712166

  3. Support of Nerve Conduction by Respiring Myelin Sheath: Role of Connexons.

    PubMed

    Ravera, Silvia; Bartolucci, Martina; Adriano, Enrico; Garbati, Patrizia; Ferrando, Sara; Ramoino, Paola; Calzia, Daniela; Morelli, Alessandro; Balestrino, Maurizio; Panfoli, Isabella

    2016-05-01

    Recently, we have demonstrated that myelin conducts an extramitochondrial oxidative phosphorylation, hypothesizing a novel supportive role for myelin in favor of the axon. We have also hypothesized that the ATP produced in myelin could be transferred thought gap junctions. In this work, by biochemical, immunohistochemical, and electrophysiological techniques, the existence of a connection among myelin to the axon was evaluated, to understand how ATP could be transferred from sheath to the axoplasm. Data confirm a functional expression of oxidative phosphorylation in isolated myelin. Moreover, WB and immunohistochemistry on optic nerve slices show that connexins 32 and 43 are present in myelin and colocalize with myelin basic protein. Interestingly, addition of carbenoxolone or oleamide, two gap junction blockers, causes a decrease in oxidative metabolism in purified myelin, but not in mitochondria. Similar effects were observed on conduction speed in hippocampal Schaffer collateral, in the presence of oleamide. Confocal analysis of optic nerve slices showed that lucifer yellow (that only passes through aqueous pores) signal was found in both the sheath layers and the axoplasma. In the presence of oleamide, but not with oleic acid, signal significantly decreased in the sheath and was lost inside the axon. This suggests the existence of a link among myelin and axons. These results, while supporting the idea that ATP aerobically synthesized in myelin sheath could be transferred to the axoplasm through gap junctions, shed new light on the function of the sheath.

  4. Sex differences in abnormal white matter development associated with conduct disorder in children.

    PubMed

    Decety, Jean; Yoder, Keith J; Lahey, Benjamin B

    2015-08-30

    Associations between white matter pathway abnormalities and antisocial personality disorder in adults are well replicated, and there is some evidence for an association of white matter abnormalities with conduct disorder (CD) in adolescents. In this study, white matter maturation using diffusion tensor imaging (DTI) was examined in 110 children aged 10.0 ± 0.8 years selected to vary widely in their numbers of CD symptoms. The results replicated age-related increases in fractional anisotropy (FA) found in previous studies. There was not a significant association between the number of CD symptoms and FA, but CD symptoms were found to be significantly associated with greater axial and radial diffusivity in a broad range of white matter tracts, particularly in girls. In complementary analyses, there were similar significant differences in axial and radial diffusivity between children who met diagnostic criteria for CD and healthy children with no symptoms of CD, particularly in girls. Brain structural abnormalities may contribute to the emergence of CD in childhood, perhaps playing a greater role in girls.

  5. Nerve conduction velocities in the lower extremities among patients with vibration syndrome.

    PubMed

    Hirata, M; Sakakibara, H; Yamada, S; Hashiguchi, T; Toibana, N; Koshiyama, H

    1995-01-01

    In order to clarify the effect of vibration syndrome (VS) on the peripheral nervous system (PNS) in the lower extremities, 59 patients with VS (age 58.5 +/- 5.1 years) and 49 age-matched controls (age 57.0 +/- 5.1 years) were examined for sensory nerve conduction velocities (SCV) in the sural nerve (SSCV) and the medial plantar nerve (PSCV) in the summer of 1993 and 1994. They had not been suffering from diseases and injuries which might have affected the SCV in the lower extremities. These patients were divided into two subgroups, one with past vibration exposure to chainsaw (N = 22) and the other with past vibration exposure to rock drills and other tools (N = 37). SCVs corrected by skin temperature were subjected to statistical analysis. In PSCV a significant reduction among all patients (40.8 +/- 4.24 m/s, p < 0.01) including two subgroups (chainsaw, 39.7 +/- 4.7 m/s, p < 0.01; rock drill and others, 41.0 +/- 4.6 m/s, p < 0.01) was observed compared with those of the controls (43.2 +/- 4.31 m/s), but there was no significant reduction in SSCV. Significantly more subjects with PSCV below the standard of PSCV (ten percentile value of those of the controls) were observed among all patients (17/59, 28.8%, p < 0.05) including two subgroups (chainsaw, 7/22, 31.8%, p < 0.05; rock drill and others, 10/37, 27.0%, p < 0.05) than in the controls (4/49, 8.2%). These findings suggested that VS affected the PNS function in the lower extremities and that its mechanism was considered to mediate a circulatory disturbance, and to differ from SCV reduction in the finger.

  6. Adaptive Optics Imaging of Healthy and Abnormal Regions of Retinal Nerve Fiber Bundles of Patients With Glaucoma

    PubMed Central

    Chen, Monica F.; Chui, Toco Y. P.; Alhadeff, Paula; Rosen, Richard B.; Ritch, Robert; Dubra, Alfredo; Hood, Donald C.

    2015-01-01

    Purpose. To better understand the nature of glaucomatous damage of the macula, especially the structural changes seen between relatively healthy and clearly abnormal (AB) retinal regions, using an adaptive optics scanning light ophthalmoscope (AO-SLO). Methods. Adaptive optics SLO images and optical coherence tomography (OCT) vertical line scans were obtained on one eye of seven glaucoma patients, with relatively deep local arcuate defects on the 10-2 visual field test in one (six eyes) or both hemifields (one eye). Based on the OCT images, the retinal nerve fiber (RNF) layer was divided into two regions: (1) within normal limits (WNL), relative RNF layer thickness within mean control values ±2 SD; and (2) AB, relative thickness less than −2 SD value. Results. As seen on AO-SLO, the pattern of AB RNF bundles near the border of the WNL and AB regions differed across eyes. There were normal-appearing bundles in the WNL region of all eyes and AB-appearing bundles near the border with the AB region. This region with AB bundles ranged in extent from a few bundles to the entire AB region in the case of one eye. All other eyes had a large AB region without bundles. However, in two of these eyes, a few bundles were seen within this region of otherwise missing bundles. Conclusions. The AO-SLO images revealed details of glaucomatous damage that are difficult, if not impossible, to see with current OCT technology. Adaptive optics SLO may prove useful in following progression in clinical trials, or in disease management, if AO-SLO becomes widely available and easy to use. PMID:25574048

  7. Which motor nerve conduction study is best in ulnar neuropathy at the elbow?

    PubMed

    Shakir, Ali; Micklesen, Paula J; Robinson, Lawrence R

    2004-04-01

    There is debate regarding how best to utilize ulnar motor nerve conduction velocity (MNCV) to identify ulnar neuropathy at the elbow (UNE). We used receiver operator characteristic (ROC) curves to compare absolute across-elbow MNCV with MNCV difference between elbow and forearm segments (VDIF) when recording from abductor digiti minimi (ADM) and first dorsal interosseous (FDI) muscles. Also, we determined how their utility was impacted by low amplitudes of compound muscle action potentials (CMAPs). We studied 85 subjects with UNE and 77 subjects with carpal tunnel syndrome but without clinical evidence of UNE. The UNE group was divided into three subgroups based on CMAP amplitude. At 95% specificity, MNCV sensitivities were 80% at ADM and 77% at FDI, and VDIF sensitivities were 51% at ADM and 38% at FDI. The ROC curves showed MNCV to be superior to VDIF across all amplitude subgroups; however, confidence intervals overlapped when amplitude was high.

  8. [Investigation of maximal motor nerve conductivity and distal latency before and after galvanic cell bath (author's transl)].

    PubMed

    Trnavsky, G

    1982-04-30

    Measurements about maximal motor nerve conductivity of ulnaris and medianus were carried out before and after constant galvanisation from neck to hand. Significant results of conductivity, distal latency and amplitude of summation potential could not be registered neither by plus nor by minus pole at the hand.

  9. Effects of lead acetate on guinea pig - cochear microphonics, action potential, and motor nerve conduction velocity

    SciTech Connect

    Yamamura, K.; Maehara, N.; Terayama, K.; Ueno, N.; Kohyama, A.; Sawada, Y.; Kishi, R.

    1987-04-01

    Segmental demyelination and axonal degeneration of motor nerves induced by lead exposure is well known in man, and animals. The effect of lead acetate exposure to man may involve the cranial nerves, since vertigo and sensory neuronal deafness have been reported among lead workers. However, there are few reports concerning the dose-effects of lead acetate both to the peripheral nerve and the cranial VII nerve with measurement of blood lead concentration. The authors investigated the effects of lead acetate to the cochlea and the VIII nerve using CM (cochlear microphonics) and AP (action potential) of the guinea pigs. The effects of lead acetate to the sciatic nerve were measured by MCV of the sciatic nerve with measurement of blood lead concentration.

  10. The Development of Electrically Conductive Polycaprolactone Fumarate-Polypyrrole Composite Materials for Nerve Regeneration

    PubMed Central

    Runge, M. Brett; Dadsetan, Mahrokh; Baltrusaitis, Jonas; Knight, Andrew M.; Ruesink, Terry; Lazcano, Eric; Lu, Lichun; Windebank, Anthony J.; Yaszemski, Michael J.

    2010-01-01

    Electrically conductive polymer composites composed of polycaprolactone fumarate and polypyrrole (PCLF-PPy) have been developed for nerve regeneration applications. Here we report the synthesis and characterization of PCLF-PPy and in vitro studies showing PCLF-PPy materials support both PC12 cell and dorsal root ganglia (DRG) neurite extension. PCLF-PPy composite materials were synthesized by polymerizing pyrrole in pre-formed PCLF scaffolds (Mn 7,000 or 18,000 g mol−1) resulting in interpenetrating networks of PCLF-PPy. Chemical compositions and thermal properties were characterized by ATR-FTIR, XPS, DSC, and TGA. PCLF-PPy materials were synthesized with five different anions (naphthalene-2-sulfonic acid sodium salt (NSA), dodecylbenzenesulfonic acid sodium salt (DBSA), dioctyl sulfosuccinate sodium salt (DOSS), potassium iodide (I), and lysine) to investigate effects on electrical conductivity and to optimize chemical composition for cellular compatibility. PCLF-PPy materials have variable electrical conductivity up to 6 mS cm−1 with bulk compositions ranging from 5 to 13.5 percent polypyrrole. AFM and SEM characterization show microstructures with a root mean squared (RMS) roughness of 1195 nm and nanostructures with RMS roughness of 8 nm. In vitro studies using PC12 cells and DRG show PCLF-PPy materials synthesized with NSA or DBSA support cell attachment, proliferation, neurite extension, and are promising materials for future studies involving electrical stimulation. PMID:20483452

  11. Conduction block of mammalian myelinated nerve by local cooling to 15-30°C after a brief heating.

    PubMed

    Zhang, Zhaocun; Lyon, Timothy D; Kadow, Brian T; Shen, Bing; Wang, Jicheng; Lee, Andy; Kang, Audry; Roppolo, James R; de Groat, William C; Tai, Changfeng

    2016-03-01

    This study aimed at understanding thermal effects on nerve conduction and developing new methods to produce a reversible thermal block of axonal conduction in mammalian myelinated nerves. In 13 cats under α-chloralose anesthesia, conduction block of pudendal nerves (n = 20) by cooling (5-30°C) or heating (42-54°C) a small segment (9 mm) of the nerve was monitored by the urethral striated muscle contractions and increases in intraurethral pressure induced by intermittent (5 s on and 20 s off) electrical stimulation (50 Hz, 0.2 ms) of the nerve. Cold block was observed at 5-15°C while heat block occurred at 50-54°C. A complete cold block up to 10 min was fully reversible, but a complete heat block was only reversible when the heating duration was less than 1.3 ± 0.1 min. A brief (<1 min) reversible complete heat block at 50-54°C or 15 min of nonblock mild heating at 46-48°C significantly increased the cold block temperature to 15-30°C. The effect of heating on cold block fully reversed within ∼40 min. This study discovered a novel method to block mammalian myelinated nerves at 15-30°C, providing the possibility to develop an implantable device to block axonal conduction and treat many chronic disorders. The effect of heating on cold block is of considerable interest because it raises many basic scientific questions that may help reveal the mechanisms underlying cold or heat block of axonal conduction. PMID:26740534

  12. Psychological performance in relation to central and peripheral nerve conduction in workers exposed to lead, zinc, and copper

    SciTech Connect

    Araki, S.; Yokoyama, K.; Aono, H.; Murata, K.

    1986-01-01

    Psychological performance was examined in relation to central and peripheral nerve conduction by means of the Wechsler Adult Intelligence Scale test, short-latency somatosensory-evoked potential (SSEP), and median nerve conduction velocity in 19 male gun-metal foundry workers exposed to lead, zinc, and copper. (Their blood lead concentrations--ie, 16-64 micrograms/dl with a mean of 42--and plasma zinc and copper concentrations were significantly higher than those of control subjects). In these workers, the score of picture completion (psychological performance) was significantly low; indicators of lead absorption, but no indicators of zinc and copper absorption, were significantly correlated with this score. The score of picture completion was significantly correlated with the N11-N13 latency of SSEP (conduction time in the spinobulbar region) in the workers; their N11-N13 latency, together with the N9 and N9-N11 latencies, was significantly prolonged and was significantly correlated with indicators of lead absorption. Furthermore, their maximal motor and sensory conduction velocities of the median nerve were significantly slowed. It is concluded that both psychological performance and central and peripheral nerve conduction may be impaired in lead-exposed workers with BPb's below approximately 60 micrograms/dl.

  13. Septin/anillin filaments scaffold central nervous system myelin to accelerate nerve conduction

    PubMed Central

    Patzig, Julia; Erwig, Michelle S; Tenzer, Stefan; Kusch, Kathrin; Dibaj, Payam; Möbius, Wiebke; Goebbels, Sandra; Schaeren-Wiemers, Nicole; Nave, Klaus-Armin; Werner, Hauke B

    2016-01-01

    Myelination of axons facilitates rapid impulse propagation in the nervous system. The axon/myelin-unit becomes impaired in myelin-related disorders and upon normal aging. However, the molecular cause of many pathological features, including the frequently observed myelin outfoldings, remained unknown. Using label-free quantitative proteomics, we find that the presence of myelin outfoldings correlates with a loss of cytoskeletal septins in myelin. Regulated by phosphatidylinositol-(4,5)-bisphosphate (PI(4,5)P2)-levels, myelin septins (SEPT2/SEPT4/SEPT7/SEPT8) and the PI(4,5)P2-adaptor anillin form previously unrecognized filaments that extend longitudinally along myelinated axons. By confocal microscopy and immunogold-electron microscopy, these filaments are localized to the non-compacted adaxonal myelin compartment. Genetic disruption of these filaments in Sept8-mutant mice causes myelin outfoldings as a very specific neuropathology. Septin filaments thus serve an important function in scaffolding the axon/myelin-unit, evidently a late stage of myelin maturation. We propose that pathological or aging-associated diminishment of the septin/anillin-scaffold causes myelin outfoldings that impair the normal nerve conduction velocity. DOI: http://dx.doi.org/10.7554/eLife.17119.001 PMID:27504968

  14. Septin/anillin filaments scaffold central nervous system myelin to accelerate nerve conduction.

    PubMed

    Patzig, Julia; Erwig, Michelle S; Tenzer, Stefan; Kusch, Kathrin; Dibaj, Payam; Möbius, Wiebke; Goebbels, Sandra; Schaeren-Wiemers, Nicole; Nave, Klaus-Armin; Werner, Hauke B

    2016-01-01

    Myelination of axons facilitates rapid impulse propagation in the nervous system. The axon/myelin-unit becomes impaired in myelin-related disorders and upon normal aging. However, the molecular cause of many pathological features, including the frequently observed myelin outfoldings, remained unknown. Using label-free quantitative proteomics, we find that the presence of myelin outfoldings correlates with a loss of cytoskeletal septins in myelin. Regulated by phosphatidylinositol-(4,5)-bisphosphate (PI(4,5)P2)-levels, myelin septins (SEPT2/SEPT4/SEPT7/SEPT8) and the PI(4,5)P2-adaptor anillin form previously unrecognized filaments that extend longitudinally along myelinated axons. By confocal microscopy and immunogold-electron microscopy, these filaments are localized to the non-compacted adaxonal myelin compartment. Genetic disruption of these filaments in Sept8-mutant mice causes myelin outfoldings as a very specific neuropathology. Septin filaments thus serve an important function in scaffolding the axon/myelin-unit, evidently a late stage of myelin maturation. We propose that pathological or aging-associated diminishment of the septin/anillin-scaffold causes myelin outfoldings that impair the normal nerve conduction velocity. PMID:27504968

  15. Phrenic nerve conduction studies in spinal cord injury: applications for diaphragmatic pacing.

    PubMed

    Alshekhlee, Amer; Onders, Raymond P; Syed, Tanvir U; Elmo, Maryjo; Katirji, Bashar

    2008-12-01

    The diaphragm pacing system (DPS) is a minimally invasive alternative to mechanical ventilation in patients with quadriplegia due to cervical myelopathy primarily caused by high cervical spinal cord injury. We evaluated 36 patients, 29 of whom had traumatic spinal cord injury, two who had a history of remote meningitis and demyelinating disease, and five who had cervical myelopathies of unknown etiology. Phrenic nerve conduction studies were performed with simultaneous fluoroscopic observation of diaphragm excursion to assess diaphragm viability. In the preoperative evaluation, diaphragm compound muscle action potentials (CMAPs) were recorded only when the diaphragm moved on fluoroscopy with ipsilateral stimulation. Twenty-six patients who were determined to have a viable diaphragm underwent DPS. Following DPS the primary outcome was the time (hours per day) that patients were able to pace and stay off the ventilator. Of 26 implanted patients, 96% (25 patients) were able to pace and tolerate being off the ventilator for more than 4 h per day. This study demonstrates that the presence of a diaphragm CMAP is associated with diaphragm movement observed by fluoroscopy in cervical myelopathy. In addition, DPS can help patients with cervical spinal cord injury to breathe unassisted by a ventilator.

  16. Self-consistent analyses for potential conduction block in nerves by an ultrashort high-intensity electric pulse

    NASA Astrophysics Data System (ADS)

    Joshi, R. P.; Mishra, A.; Hu, Q.; Schoenbach, K. H.; Pakhomov, A.

    2007-06-01

    Simulation studies are presented that probe the possibility of using high-field (>100kV/cm) , short-duration (˜50ns) electrical pulses for nonthermal and reversible cessation of biological electrical signaling pathways. This would have obvious applications in neurophysiology, clinical research, neuromuscular stimulation therapies, and even nonlethal bioweapons development. The concept is based on the creation of a sufficiently high density of pores on the nerve membrane by an electric pulse. This modulates membrane conductance and presents an effective “electrical short” to an incident voltage wave traveling across a nerve. Net blocking of action potential propagation can then result. A continuum approach based on the Smoluchowski equation is used to treat electroporation. This is self-consistently coupled with a distributed circuit representation of the nerve dynamics. Our results indicate that poration at a single neural segment would be sufficient to produce an observable, yet reversible, effect.

  17. Recovery of the ipsilateral oculotectal projection following nerve crush in the frog: evidence that retinal afferents make synapses at abnormal tectal locations.

    PubMed

    Adamson, J; Burke, J; Grobstein, P

    1984-10-01

    The ipsilateral oculotectal projection in the frog is a topographic mapping of the binocular part of the visual field of one eye on the ipsilateral tectal lobe. The underlying neuronal circuitry consists of the topographic, crossed retinotectal projection and an intertectal pathway which relays information from a given point in one tectal lobe to the visually corresponding point in the other. During optic nerve regeneration, there is a period when the terminals of retinotectal afferents are found at abnormal locations in the opposite tectal lobe. Whether they form functional synapses at this time is not known. If so, one would expect to observe correlated abnormalities in the ipsilateral oculotectal projection. To determine whether such abnormalities exist, we have made parallel electrophysiological studies of the recovery of the retinotectal and ipsilateral oculotectal projections following crush of one optic nerve. The earliest stage of recovery was characterized by a lack of significant topographic order in the retinotectal projection and by the absence of a physiologically observable ipsilateral projection. Within a short time, the retinotectal projection became topographically organized and a similarly organized ipsilateral projection appeared. While topographic, the retinotectal projection at intermediate times was abnormal in that the multiunit receptive fields recorded at individual tectal loci were greatly enlarged. Multiunit receptive fields were similarly enlarged in the ipsilateral projection. In addition, some ipsilateral fields included areas of visual space not normally represented in the projection. The abnormalities in both projections subsequently disappeared over the same time course. Throughout recovery there was a high correlation between multiunit receptive field sizes in the contralateral tectal lobe and those at visually corresponding points in the ipsilateral tectal lobe. Enlarged multiunit receptive fields in the contralateral tectal lobe

  18. Association Between Genetic Variation in the SCN10A Gene and Cardiac Conduction Abnormalities in Patients With Hypertrophic Cardiomyopathy.

    PubMed

    Iio, Chiharuko; Ogimoto, Akiyoshi; Nagai, Takayuki; Suzuki, Jun; Inoue, Katsuji; Nishimura, Kazuhisa; Uetani, Teruyoshi; Okayama, Hideki; Okura, Takafumi; Shigematsu, Yuji; Tabara, Yasuharu; Kohara, Katsuhiko; Miki, Tetsuro; Hamada, Mareomi; Higaki, Jitsuo

    2015-01-01

    Arrhythmias are associated with reduced quality of life and poor prognosis in patients with hypertrophic cardiomyopathy (HCM). Recent genome-wide association studies revealed that a nonsynonymous single nucleotide polymorphism, rs6795970, in the SCN10A gene was associated with the PR interval. We examined whether the PR prolonging allele (A allele) in the SCN10A gene may be associated with cardiac conduction abnormalities in HCM patients.We genotyped the polymorphism in 149 HCM patients. Conduction abnormalities were defined as first-degree heart block, bundle-branch block, and bifascicular heart block. Patients were divided into two groups: group A consisted of 122 patients (82%) without a conduction abnormality; and group B consisted of 27 patients (18%) with one or more cardiac conduction abnormalities. The frequency distribution of the SCN10A genotypes (G/G, G/A, and A/A) among the patients with HCM was 71%, 26%, and 3%, respectively. A cardiac conduction abnormality was documented in 9% with G/G and 40% with G/A or A/A. There was a significant difference in the genotype distribution between the two groups (P = 0.0002). In the dominant A allele model, there was a significant difference in genotypes between the two groups (P < 0.0001). In addition, the A allele remained significant after adjusting for other covariates in a multivariate model (odds ratio = 6.30 [95% confidence interval: 2.24 to 19.09], P = 0.0005).The rs6795970 in the SCN10A gene, which is reported to carry a high risk of heart block, might be associated with cardiac conduction abnormalities in HCM patients. PMID:26104176

  19. Ionic channels and signal conduction in single remyelinating frog nerve fibres.

    PubMed Central

    Shrager, P

    1988-01-01

    1. Ionic currents have been measured in single demyelinated and remyelinating frog sciatic nerve fibres by means of the loose patch clamp technique. Axons were demyelinated by a surgical intraneural injection of lysolecithin and recovery was followed for up to 5 months. 2. Removal of myelin debris continued for the first 2 weeks post-injection. Proliferating Schwann cells were then seen within the lesion. As remyelination proceeded new nodes of Ranvier were formed in regions that previously were internodal. Original nodes, marking the transition from old to new myelin, could be identified at all stages. 3. Peak amplitudes of internodal transient inward Na+ currents were constant over the first 2 months and increased by about 60% after 5 months. Internodal currents in remyelinated axons were recorded after a second injection of lysolecithin to remove the thin myelin sheath. 4. Records from paranodal sites neighbouring transition nodes contained transient outward currents that were strongly voltage dependent and seemed to reflect activation of a very high density of Na+ channels just outside the patch. This sharp gradient in channel density at original nodes persisted throughout the period of remyelination studied suggesting that lateral diffusion from these sites is limited. These currents were never seen at internodal sites nor were they found at new nodes of Ranvier. 5. Paranodal inward current amplitudes in new nodes were similar to those in original (transition) nodes. 6. No transient inward Na+ currents were detected in Schwann cells adhering to demyelinated axons or free standing within the area of the lesion. 7. Conduction in single remyelinating fibres was studied by measuring membrane currents that flowed in response to an invading propagating action potential. At 2 weeks post-injection, prior to the formation of myelin, conduction was decremental, but activation of internodal Na+ channels allowed signals to penetrate further into the demyelinated zone than

  20. Morphological abnormalities in myelinated nerve fibres caused by Leiurus, Centruroides and Phoneutria venoms and their prevention by tetrodotoxin.

    PubMed

    Love, S; Cruz-Höfling, M A; Duchen, L W

    1986-01-01

    Morphological changes in peripheral nerve caused by the venoms of the scorpions Leiurus quinquestriatus and Centruroides sculpturatus were compared with those caused by Phoneutria nigriventer spider venom. Both scorpion venoms are known to delay the inactivation of sodium currents, Centruroides venom also altering the voltage dependence of sodium gating. Venom was injected by means of a glass micropipette into the sciatic nerves of anaesthetized mice. After survival times ranging from 15 min to 24 h the nerves were examined by light and electron microscopy. The two scorpion venoms caused alterations virtually identical to those produced by Phoneutria venom, which included swelling of the nodal axoplasm and accumulation of fluid in the periaxonal space of myelinated fibres. These alterations were most marked after 1 to 2 h and had largely disappeared by 24 h. Pre-treatment of the nerves with tetrodotoxin, which specifically blocks sodium channels, completely prevented both the nodal axoplasmic swelling and the periaxonal oedema. It seems likely that these effects result from an action common to the three venoms and that this is probably a delay in the inactivation of sodium current at the node of Ranvier.

  1. The Effect of Low Omega-3/Omega-6 Ratio on Auditory Nerve Conduction in Rat Pups.

    PubMed

    Farahani, Saeid; Motasaddi Zarandy, Masoud; Hassanzadeh, Gholamreza; Shidfar, Farzad; Jalaie, Shohreh; Rahimi, Vida

    2015-01-01

    The biological effects of omega-3 and omega-6 fatty acids are determined by their mutual interactions. This interaction extremely affects various functions. Lower consumption of omega-3 during gestation leads to various disorders, even in hearing. We aimed to assess the effect of low omega-3/omega-6 ratios on auditory nerve conduction. In this experimental study, the auditory brainstem response test was performed on 24-day-old rat (n=14). The rats were divided into case (low omega-3/omega-6 ratio during gestation and lactation) and control groups. Variables such as P1, P3, and P4 absolute latency period, interpeaks (P3-P4, P1-P3, and P1-P4), and P4/P1 amplitude ratio were measured. We found an increased P4 omega-3/omega-6 ratio in the group with a low omega-3/omega-6 ratio (P<0.01). No significant difference was observed in the P1 and P3 absolute latency period between the studied groups  (P>0.05).  Also, no significant difference was observed between the groups with respect to the P1-P3 interpeak latency (IPL) periods (P>0.05); while the P1-P4 and P3-P4 IPLs were significantly increased in the group with a low omega-3/omega-6 ratio (P<0.05). The P4/P1 amplitude ratio significantly decreased in the group with a low omega-3/omega-6 ratio (P<0.05). Results confirmed the negative effects of low omega-3/omega-6 ratio on the auditory system and hearing.

  2. Reproducibility of normal facial motor nerve conduction studies and their relevance in the electrophysiological assessment of peripheral facial paralysis.

    PubMed

    Di Bella, P; Logullo, F; Lagalla, G; Sirolla, C; Provinciali, L

    1997-09-01

    To determine the intra-examiner intertrial reproducibility of normal facial motor nerve conduction studies (FNCS) and their relevance in electrophysiological assessments of peripheral facial paralysis, 52 patients with acute unilateral Bell's palsy were examined on two separate occasions 1 months apart. Three electroneurographic methods were assessed. On the unaffected side of the face, FNCS are reliable when performed by a single examiner over time. Nevertheless, compound muscle action potential (CMAP) baseline-to-peak and peak-to-peak amplitude showed a rather high intertrial variability. Reproducibility of the assessed surface electrode recording procedures was similar. Regarding the affected side, in patients with mild axonotmesis of the facial nerve variations of electroneurographic parameters 1 months apart fell within the range of normal intertrial variability. In patients with severe or moderate axonotmesis, the distal latency and the M wave amplitude variations showed significant intertrial variations. Reproducibility of FNCS appears to be similar to that found in limb motor nerves. Normal variability curtails the sensitivity of FNCS in detecting mild facial nerve axonotmesis, although this technique remains useful in severe cases.

  3. Cytocompatibility of a conductive nanofibrous carbon nanotube/poly (L-Lactic acid) composite scaffold intended for nerve tissue engineering

    PubMed Central

    Kabiri, Mahboubeh; Oraee-Yazdani, Saeed; Dodel, Masumeh; Hanaee-Ahvaz, Hana; Soudi, Sara; Seyedjafari, Ehsan; Salehi, Mohammad; Soleimani, Masoud

    2015-01-01

    The purpose of this study was to fabricate a conductive aligned nanofibrous substrate and evaluate its suitability and cytocompatibility with neural cells for nerve tissue engineering purposes. In order to reach these goals, we first used electrospinning to fabricate single-walled carbon-nanotube (SWCNT) incorporated poly(L-lactic acid) (PLLA) nanofibrous scaffolds and then assessed its cytocompatibility with olfactory ensheathing glial cells (OEC). The plasma treated scaffolds were characterized using scanning electron microscopy and water contact angle. OECs were isolated from olfactory bulb of GFP Sprague-Dawley rats and characterized using OEC specific markers via immunocytochemistry and flow cytometery. The cytocompatibility of the conductive aligned nano-featured scaffold was assessed using microscopy and MTT assay. We indicate that doping of PLLA polymer with SWCNT can augment the aligned nanosized substrate with conductivity, making it favorable for nerve tissue engineering. Our results demonstrated that SWCNT/PLLA composite scaffold promote the adhesion, growth, survival and proliferation of OEC. Regarding the ideal physical, topographical and electrical properties of the scaffold and the neurotrophic and migratory features of the OECs, we suggest this scaffold and the cell/scaffold construct as a promising platform for cell delivery to neural defects in nerve tissue engineering approaches. PMID:26600751

  4. Experimental studies of the effects of extrinsic factors on conduction in normal and demyelinated nerve. 1. Temperature.

    PubMed Central

    Davis, F A; Schauf, C L; Reed, B J; Kesler, R L

    1976-01-01

    Previous studies in experimentally demyelinated mammalian nerves have demonstrated that a reversible conduction block occurs with small increases of temperature within the animal's normal body temperature range. This phenomenon is believed to be the mechanism for clinical temperature effects in multiple sclerosis. This study examines some quantitative thermal relationships in demyelinated nerves of guinea pigs with experimental allergic neuritis. The observed results in normal and experimental animals are in good agreement with previous theoretical calculations based on the effects of temperature on the voltage and time-dependent behavior of the ionic permeabilities of the nodes of Ranvier. Guinea pigs with increasing motor dysfunction generally exhibited corresponding increases in the overall latency of the conducted action potential, as well as decreases in amplitude. In addition, the lower the initial velocity increment per degree of temperature elevation, the lower was the temperature at which conduction block began to occur. Except for a few cases in which the recorded action potential was bimodal, with response at both normal and prolonged latency, the results tended to indicate a remarkedly uniform involvement of the sciatic nerve within the region of temperature control. PMID:932762

  5. Effect of Treating Streptozotocin-Induced Diabetic Rats With Sorbinil, Myo-Inositol or Aminoguanidine on Endoneurial Blood Flow, Motor Nerve Conduction Velocity and Vascular Function of Epineurial Arterioles of the Sciatic Nerve

    PubMed Central

    Coppey, Lawrence J.; Gellett, Jill S.; Davidson, Eric P.; Dunlap, Joyce A.

    2002-01-01

    Previously we have demonstrated that diabetes causes impairment in vascular function of epineurial vessels, which precedes the slowing of motor nerve conduction velocity. Treatment of diabetic rats with aldose reductase inhibitors, aminoguanidine or myo-inositol supplementation have been shown to improve motor nerve conduction velocity and/or decreased endoneurial blood flow. However, the effect these treatments have on vascular reactivity of epineurial vessels of the sciatic nerve is unknown. In these studies we examined the effect of treating streptozotocininduced rats with sorbinil, aminoguanidine or myo-inositol on motor nerve conduction velocity, endoneurial blood flow and endothelium dependent vascular relaxation of arterioles that provide circulation to the region of the sciatic nerve. Treating diabetic rats with sorbinil, aminoguanidine or myo-inositol improved the reduction of endoneurial blood flow and motor nerve conduction velocity. However, only sorbinil treatment significantly improved the diabetes-induced impairment of acetylcholinemediated vasodilation of epineurial vessels of the sciatic nerve. All three treatments were efficacious in preventing the appropriate metabolic derangements associated with either activation of the polyol pathway or increased nonenzymatic glycation. In addition, sorbinil was shown to prevent the diabetes-induced decrease in lens glutathione level. However, other markers of oxidative stress were not vividly improved by these treatments. These studies suggest that sorbinil treatment may be more effective in preventing neural dysfunction in diabetes than either aminoguanidine or myoinositol. PMID:11900277

  6. Anti-neurofilament antibodies in neuropathy with monoclonal gammopathy of undetermined significance produce experimental motor nerve conduction block.

    PubMed

    Stubbs, Evan B; Lawlor, Mike W; Richards, Michael P; Siddiqui, Kiran; Fisher, Morris A; Bhoopalam, Nirmala; Siegel, George J

    2003-02-01

    Elevated levels of serum antibodies to neurofilament proteins have been associated with a variety of neurological diseases, including autoimmune disorders such as neuropathy with monoclonal gammopathy of undetermined significance (MGUS). The pathological significance of anti-neurofilament antibodies in sera of affected patients, however, remains unclear. In this study, we report our findings of polyclonal antibodies in sera from 4 of 16 IgG MGUS neuropathy patients that react strongly on immunoblot with a high molecular weight neurofilament protein (NFH). The effect of anti-NFH polyclonal antibody on peripheral nerve function was tested in vivo by intraneural injection. Sera containing anti-NFH antibody, but not sera from age-matched control subjects, injected into the endoneurium of rat sciatic nerve significantly attenuated proximal-evoked motor nerve compound muscle action potential (CMAP) amplitudes in a complement-dependent manner. In contrast, ankle-evoked CMAP amplitudes were unaffected by intraneural injection of sera containing anti-NFH antibody. Anti-NFH serum-injected nerves showed changes in both axon caliber (shrinkage) and myelin ultrastructure (vesiculation and ovoid formation), suggestive of intramyelinic edema. Preincubation of sera containing anti-NFH antibody with purified NFH protein abolished immunoreactivity to NFH protein and neutralized the serum-mediated toxicity. The data suggest that anti-NFH polyclonal antibodies occurring in sera of some patients with IgG MGUS neuropathy may elicit peripheral nerve conduction block independent of the patients' IgG paraprotein. Anti-neural polyclonal antibodies in sera of IgG MGUS neuropathy patients may have a greater pathological significance than previously anticipated.

  7. Α-Dendrotoxin-sensitive Kv1 channels contribute to conduction failure of polymodal nociceptive C-fibers from rat coccygeal nerve.

    PubMed

    Wang, Xiu-Chao; Wang, Shan; Zhang, Ming; Gao, Fang; Yin, Chun; Li, Hao; Zhang, Ying; Hu, San-Jue; Duan, Jian-Hong

    2016-02-01

    It is known that some patients with diabetic neuropathy are usually accompanied by abnormal painful sensations. Evidence has accumulated that diabetic neuropathic pain is associated with the hyperexcitability of peripheral nociceptors. Previously, we demonstrated that reduced conduction failure of polymodal nociceptive C-fibers and enhanced voltage-dependent sodium currents of small dorsal root ganglion (DRG) neurons contribute to diabetic hyperalgesia. To further investigate whether and how potassium channels are involved in the conduction failure, α-dendrotoxin (α-DTX), a selective blocker of the low-threshold sustained Kv1 channel, was chosen to examine its functional capability in modulating the conduction properties of polymodal nociceptive C-fibers and the excitability of sensory neurons. We found that α-DTX reduced the conduction failure of C-fibers from coccygeal nerve in vivo accompanied by an increased initial conduction velocity but a decreased activity-dependent slowing of conduction velocity. In addition, the number of APs evoked by step currents was significantly enhanced after the treatment with α-DTX in small-diameter sensory neurons. Further study of the mechanism indicates α-DTX-sensitive K(+) current significantly reduced and the activation of this current in peak and steady state shifted to depolarization for diabetic neurons. Expression of Kv channel subunits Kv1.2 and Kv1.6 was downregulated in both small dorsal root ganglion neurons and peripheral C-fibers. Taken together, these results suggest that α-DTX-sensitive Kv1 channels might play an important role in regulating the conduction properties of polymodal nociceptive C-fibers and firing properties of sensory neurons.

  8. In vivo studies of Scn5a+/− mice modeling Brugada syndrome demonstrate both conduction and repolarization abnormalities

    PubMed Central

    Martin, Claire A.; Zhang, Yanmin; Grace, Andrew A.; Huang, Christopher L.-H.

    2010-01-01

    Objectives We investigate the extent to which the electrocardiographic (ECG) properties of intact Scn5a+/− mice reproduce the corresponding clinical Brugada syndrome phenotype and use this model to investigate the role of conduction and repolarization abnormalities in the arrhythmogenic mechanism. Methods and Results The ECGs were obtained from anesthetized wild-type and Scn5a+/− mice, before and after administration of the known pro- and antiarrhythmic agents flecainide and quinidine. The ECG intervals were measured and their dispersions calculated. Scn5a+/− hearts showed ventricular arrhythmias, ST elevation, and conduction disorders including increased QT dispersion, accentuated by flecainide. Quinidine did not cause ventricular arrhythmias but exerted variable effects on ST segments and worsened conduction abnormalities. Conclusions The ECG features in an Scn5a+/− mouse establish it as a suitable model for Brugada syndrome and demonstrate abnormal conduction and repolarization phenomena. Altered QT dispersion, taken to indicate increased transmural repolarization gradients, may be useful in clinical risk stratification. PMID:20638671

  9. Association of interatrial septal abnormalities with cardiac impulse conduction disorders in adult patients: experience from a tertiary center in Kosovo

    PubMed Central

    Bakalli, Aurora; Pllana, Ejup; Koçinaj, Dardan; Bekteshi, Tefik; Dragusha, Gani; Gashi, Masar; Musliu, Nebih; Gashi, Zaim

    2011-01-01

    Interatrial septal disorders, which include: atrial septal defect, patent foramen ovale and atrial septal aneurysm, are frequent congenital anomalies found in adult patients. Early detection of these anomalies is important to prevent their hemodynamic and/or thromboembolic consequences. The aims of this study were: to assess the association between impulse conduction disorders and anomalies of interatrial septum; to determine the prevalence of different types of interatrial septum abnormalities; to assess anatomic, hemodynamic, and clinical consequences of interatrial septal pathologies. Fifty-three adult patients with impulse conduction disorders and patients without ECG changes but with signs of interatrial septal abnormalities, who were referred to our center for echocardiography, were included in a prospective transesophageal echocardiography study. Interatrial septal anomalies were detected in around 85% of the examined patients. Patent foramen ovale was encountered in 32% of the patients, and in combination with atrial septal aneurysm in an additional 11.3% of cases. Atrial septal aneurysm and atrial septal defect were diagnosed with equal frequency in 20.7% of our study population. Impulse conduction disorders were significantly more suggestive of interatrial septal anomalies than clinical signs and symptoms observed in our patients (84.91% vs 30.19%, P=0.002). Right bundle branch block was the most frequent impulse conduction disorder, found in 41 (77.36%) cases. We conclude that interatrial septal anomalies are highly associated with impulse conduction disorders, particularly with right bundle branch block. Impulse conduction disorders are more indicative of interatrial septal abnormalities in earlier stages than can be understood from the patient’s clinical condition. PMID:21977304

  10. Tension neuropathy of the superficial peroneal nerve: associated conditions and results of release.

    PubMed

    Johnston, E C; Howell, S J

    1999-09-01

    We reviewed eight patients who sustained superficial peroneal nerve neuralgia after an inversion ankle sprain. Surgical exploration found anatomic abnormalities that tethered the nerve from movement during plantarflexion and inversion of the ankle. Most patients' pain improved dramatically after release and anterior transposition of the nerve. Seven joints also underwent arthroscopy, which showed intra-articular disease that was consistent with the original trauma. Five patients had reflex sympathetic dystrophy, three of which resolved after nerve release. Nerve conduction studies were not helpful. Careful physical examination and local nerve blocks were most important in making the diagnosis and prescribing treatment. All conservative measures should be exhausted before surgery is considered.

  11. Increasing strength and conductivity of Cu alloy through abnormal plastic deformation of an intermetallic compound

    PubMed Central

    Han, Seung Zeon; Lim, Sung Hwan; Kim, Sangshik; Lee, Jehyun; Goto, Masahiro; Kim, Hyung Giun; Han, Byungchan; Kim, Kwang Ho

    2016-01-01

    The precipitation strengthening of Cu alloys inevitably accompanies lowering of their electric conductivity and ductility. We produced bulk Cu alloys arrayed with nanofibers of stiff intermetallic compound through a precipitation mechanism using conventional casting and heat treatment processes. We then successfully elongated these arrays of nanofibers in the bulk Cu alloys to 400% of original length without breakage at room temperature using conventional rolling process. By inducing such an one-directional array of nanofibers of intermetallic compound from the uniform distribution of fine precipitates in the bulk Cu alloys, the trade-off between strength and conductivity and between strength and ductility could be significantly reduced. We observed a simultaneous increase in electrical conductivity by 1.3 times and also tensile strength by 1.3 times in this Cu alloy bulk compared to the conventional Cu alloys. PMID:27488621

  12. Increasing strength and conductivity of Cu alloy through abnormal plastic deformation of an intermetallic compound

    NASA Astrophysics Data System (ADS)

    Han, Seung Zeon; Lim, Sung Hwan; Kim, Sangshik; Lee, Jehyun; Goto, Masahiro; Kim, Hyung Giun; Han, Byungchan; Kim, Kwang Ho

    2016-08-01

    The precipitation strengthening of Cu alloys inevitably accompanies lowering of their electric conductivity and ductility. We produced bulk Cu alloys arrayed with nanofibers of stiff intermetallic compound through a precipitation mechanism using conventional casting and heat treatment processes. We then successfully elongated these arrays of nanofibers in the bulk Cu alloys to 400% of original length without breakage at room temperature using conventional rolling process. By inducing such an one-directional array of nanofibers of intermetallic compound from the uniform distribution of fine precipitates in the bulk Cu alloys, the trade-off between strength and conductivity and between strength and ductility could be significantly reduced. We observed a simultaneous increase in electrical conductivity by 1.3 times and also tensile strength by 1.3 times in this Cu alloy bulk compared to the conventional Cu alloys.

  13. Increasing strength and conductivity of Cu alloy through abnormal plastic deformation of an intermetallic compound.

    PubMed

    Han, Seung Zeon; Lim, Sung Hwan; Kim, Sangshik; Lee, Jehyun; Goto, Masahiro; Kim, Hyung Giun; Han, Byungchan; Kim, Kwang Ho

    2016-01-01

    The precipitation strengthening of Cu alloys inevitably accompanies lowering of their electric conductivity and ductility. We produced bulk Cu alloys arrayed with nanofibers of stiff intermetallic compound through a precipitation mechanism using conventional casting and heat treatment processes. We then successfully elongated these arrays of nanofibers in the bulk Cu alloys to 400% of original length without breakage at room temperature using conventional rolling process. By inducing such an one-directional array of nanofibers of intermetallic compound from the uniform distribution of fine precipitates in the bulk Cu alloys, the trade-off between strength and conductivity and between strength and ductility could be significantly reduced. We observed a simultaneous increase in electrical conductivity by 1.3 times and also tensile strength by 1.3 times in this Cu alloy bulk compared to the conventional Cu alloys. PMID:27488621

  14. Easy Method to Examine Single Nerve Fiber Excitability and Conduction Parameters Using Intact Nonanesthetized Earthworms

    ERIC Educational Resources Information Center

    Bähring, Robert; Bauer, Christiane K.

    2014-01-01

    The generation and conduction of neuronal action potentials (APs) were the subjects of a cell physiology exercise for first-year medical students. In this activity, students demonstrated the all-or-none nature of AP generation, measured conduction velocity, and examined the dependence of the threshold stimulus amplitude on stimulus duration. For…

  15. Hypovitaminosis D in widespread pain: its effect on pain perception, quality of life and nerve conduction studies.

    PubMed

    Kuru, Pinar; Akyuz, Gulseren; Yagci, Ilker; Giray, Esra

    2015-02-01

    The aim of the study was to investigate the effects of hypovitaminosis D on pain, quality of life (QoL) and nerve conduction studies (NCSs) in patients with chronic widespread pain (CWP). We randomly selected 83 female patients with CWP according to their vitamin D levels in this cross-sectional study. Patients were divided into two groups as sufficient vitamin D level (above 20 ng/ml) and deficient vitamin D level (below 20 ng/ml, hypovitaminosis D). Various pain scales and Nottingham Health Profile (NHP) were used. NCSs were also done. In patients with hypovitaminosis D, there were significantly higher pain scores for all scales (p value range 0.002-0.027). The subscale and total NHP scores were significantly higher in hypovitaminosis D group (p = 0.048-0.001) except social isolation subscale (p = 0.553). Vitamin D levels were in negative correlation with right and left median and/or ulnar motor nerve amplitudes, left tibial motor amplitude. This study confirm that hypovitaminosis D is related with higher pain intensity and lower QoL scores in patients with CWP when compared with control group. Additionally, we identified for the first time that there were negative correlations between vitamin D levels and some findings of NCSs.

  16. Hypovitaminosis D in widespread pain: its effect on pain perception, quality of life and nerve conduction studies.

    PubMed

    Kuru, Pinar; Akyuz, Gulseren; Yagci, Ilker; Giray, Esra

    2015-02-01

    The aim of the study was to investigate the effects of hypovitaminosis D on pain, quality of life (QoL) and nerve conduction studies (NCSs) in patients with chronic widespread pain (CWP). We randomly selected 83 female patients with CWP according to their vitamin D levels in this cross-sectional study. Patients were divided into two groups as sufficient vitamin D level (above 20 ng/ml) and deficient vitamin D level (below 20 ng/ml, hypovitaminosis D). Various pain scales and Nottingham Health Profile (NHP) were used. NCSs were also done. In patients with hypovitaminosis D, there were significantly higher pain scores for all scales (p value range 0.002-0.027). The subscale and total NHP scores were significantly higher in hypovitaminosis D group (p = 0.048-0.001) except social isolation subscale (p = 0.553). Vitamin D levels were in negative correlation with right and left median and/or ulnar motor nerve amplitudes, left tibial motor amplitude. This study confirm that hypovitaminosis D is related with higher pain intensity and lower QoL scores in patients with CWP when compared with control group. Additionally, we identified for the first time that there were negative correlations between vitamin D levels and some findings of NCSs. PMID:25085713

  17. Abnormalities of atrioventricular conduction in patients with the Lown-Ganong-Levine syndrome.

    PubMed

    Pavlovic, J; Fabián, J; Belán, A

    1978-01-01

    In 18 patients with the Lown-Ganong-Levine syndrome and in 11 control subjects the response of the atrioventricular conduction system to heart rate acceleration by right atrial pacing, and, with the aid of His bundle electrogram, the behaviour of individual levels of the atrioventricular conduction system were studied. At spontaneous sinus rhythm A-H interval was shorter in the patients with the Lown-Ganong-Levine syndrome than in the controls. In the latter the A-H interval became markedly prolonged, up to a Wenckebach-type IInd-degree AV block, already at a minor pacing-induced acceleration of the heart rate, whereas in the patients with the Lown-Ganong-Levine syndrome the atrioventricular propagation of excitation at a 1:1 ratio remained preserved even at substantially higher heart-rate values. On the basis of the responses of the A-H interval to pacing the patients with the Lown-Ganong-Levine syndrome were classed into four types.

  18. Experimental validation of the nerve conduction velocity selective recording technique using a multi-contact cuff electrode.

    PubMed

    Yoshida, K; Kurstjens, G A M; Hennings, K

    2009-12-01

    The earthworm (Lumbricus terrestris) is presented as an in vitro model of a peripheral nerve containing only two fibers each with distinctly different conduction velocities, the median and lateral giant fibers (MGF and LGF). The worm model is used with a multi-contact cuff electrode to validate the spatial-temporal filtering effect of different electrode contact configurations and the effect of applying a delay adder and matched filter tuned to either the MGF or LGF action potential (AP) to extract conduction direction and velocity from the recording. The results confirmed the known effect of inter-electrode spacing and bipolar and tripolar recording configuration on the AP amplitude. It also demonstrates a crossover point where the amplitude of the tripolar recording is larger than the monopolar recording, an effect of the slower action potential conduction velocities in the worm. The delay adder was found to be an effective velocity sensitive filter, able to discriminate units based on conduction velocity. The matched filter to be an effective means to eliminate artifact and increase signal to noise ratios, however was not found to improve selectivity. PMID:19762269

  19. Point-of-service nerve conduction studies: an example of industry-driven disruptive innovation in health care.

    PubMed

    Lesser, Eugene A; Starr, Jennifer; Kong, Xuan; Megerian, J Thomas; Gozani, Shai N

    2007-01-01

    Nerve conduction studies (NCS) and needle electromyography are useful and established diagnostic procedures for evaluating patients with signs and symptoms of neuromuscular disease. Although technological advances have occurred since the introduction of commercial electromyography instrumentation in the 1950s, most improvements have been evolutionary and were designed to benefit traditional users--neurologists and physiatrists specializing in electromyography. In the past seven years, instruments have been introduced that automate NCS and thereby enable a broader group of physicians, including internists and orthopedic surgeons, to perform these studies and utilize electromyographic data in the care of their patients. Automated NCS devices are an example of what Clayton Christensen terms a "disruptive innovation." In this article, automated NCS is contrasted with traditional electromyography, and the challenges and opposition to its widespread adoption are explored.

  20. Central motor conduction in multiple sclerosis: evaluation of abnormalities revealed by transcutaneous magnetic stimulation of the brain.

    PubMed Central

    Ingram, D A; Thompson, A J; Swash, M

    1988-01-01

    Magnetic stimulation of the brain and spinal column was used to assess conduction in the descending central motor pathways controlling arm and leg muscles of 20 patients with multiple sclerosis, and 10 normal subjects. The multiple sclerosis patients had relapsing and remitting disease but all were ambulant and in stable clinical remission. Increased central motor conduction times (CMCTs), up to three times normal, were frequently encountered in multiple sclerosis patients and in leg muscles these correlated closely with clinical signs of upper motor neuron disturbance; in the upper limb muscles a higher proportion of subclinical lesions was present. Weak muscles were almost invariably associated with abnormal central conduction but increased CMCTs were also found for 52 of the 104 muscles with normal strength. CMCTs for lower limb muscles were directly related (p less than 0.005) to functional motor disability (Kurtzke and Ambulatory Index Scales). No patient developed clinical evidence of relapse during follow-up of at least 8 months. Magnetic brain stimulation is easy to perform, painless, and safe, and provides clinically relevant information in the diagnosis and monitoring of multiple sclerosis patients. PMID:2837538

  1. Axolemmal and septal conduction in the impedance of the earthworm medial giant nerve fiber.

    PubMed Central

    Krause, T L; Fishman, H M; Bittner, G D

    1994-01-01

    Ionic conduction in the axolemmal and septal membranes of the medial giant fiber (MGF) of the earthworm (EW) Lumbricus terrestris was assessed by impedance spectroscopy in the frequency range 2.5-1000 Hz. Impedance loci in the complex plane were described by two semi-circular arcs, one at a lower characteristic frequency (100 Hz) and the other at a higher frequency (500 Hz). The lower frequency arc had a chord resistance of 53 k omega and was not affected by membrane potential changes or ion channel blockers [tetrodotoxin (TTX), 3,4-diaminopyridine (3,4-DAP), 4-aminopyridine (4-AP), and tetraethylammonium (TEA)]. The higher frequency arc had a chord resistance of 274 k omega at resting potential, was voltage-dependent, and was affected by the addition of TTX, 3,4-DAP, 4-AP, and TEA to the physiological EW salines. When all four blockers were added to the bathing solution, the impedance locus was described by two voltage-independent arcs. Considering the effects of these and other (i.e., Cd and Ni) ion channel blockers, we conclude that: 1) the higher frequency locus reflects conduction by voltage-sensitive ion channels in the axolemmal membrane, which contains at least four ion channels selective for sodium, calcium, and potassium (delayed rectifier and calcium-dependent), and 2) the lower frequency locus reflects voltage-insensitive channels in the septal membrane, which separates adjacent MGFs. PMID:7524713

  2. Relation of Na+, K(+)-ATPase to delayed motor nerve conduction velocity: effect of aldose reductase inhibitor, ADN-138, on Na+, K(+)-ATPase activity.

    PubMed

    Hirata, Y; Okada, K

    1990-06-01

    The role of sorbitol, myo-inositol, and Na+, K(+)-adenosine triphosphatase (ATPase) activity on motor nerve conduction velocity (MNCV) in streptozotocin (STZ)-diabetic rats was studied. Reduction of MNCV and Na+, K(+)-ATPase in caudal nerves appeared after 3 weeks of diabetes, and at this time treatment with aldose reductase inhibitor (ARI), ADN-138 and 1% myo-inositol supplement was begun. One percent myo-inositol supplement for 3 weeks resulted in a significant increase in myo-inositol levels in diabetic nerves, but left MNCV and sorbitol levels unchanged. In contrast, treatment with ADN-138 for 3 weeks reduced sorbitol levels in diabetic nerves and resulted in significant increases in MNCV and Na+, K(+)-ATPase in the nerves. Since ADN-138 did not restore myo-inositol levels, the increase in Na+, K(+)-ATPase levels by ADN-138 treatment was independent of myo-inositol levels. Also, nerve Na+ levels in ADN-138-treated rats were reduced and the ratio of K+ to Na+ was raised, while 1% myo-inositol supplement did not affect them. These results suggest that treatment with ADN-138 elevates MNCV through a series of processes: ARI----reduction of sorbitol level----increase in Na+, K(+)-ATPase activity----correction of K+, Na+ imbalance----increase in MNCV.

  3. Postoperative improvement in DASH score, clinical findings, and nerve conduction velocity in patients with cubital tunnel syndrome

    PubMed Central

    Ido, Yoshikazu; Uchiyama, Shigeharu; Nakamura, Koichi; Itsubo, Toshiro; Hayashi, Masanori; Hata, Yukihiko; Imaeda, Toshihiko; Kato, Hiroyuki

    2016-01-01

    We investigated a recovery pattern in subjective and objective measures among 52 patients with cubital tunnel syndrome after anterior subcutaneous transposition of the ulnar nerve. Disabilities of the Arm, Shoulder and Hand (DASH) score (primary outcome), numbness score, grip and pinch strength, Semmes-Weinstein (SW) score, static 2-point discrimination (2PD) score, and motor conduction velocity (MCV) stage were examined preoperatively and 1, 3, 6, 12, and ≥24 months postoperatively. Statistical analyses were conducted to evaluate how each variable improved after surgery. A linear mixed-effects model was used for continuous variables (DASH score, numbness, grip and pinch strength), and a proportional odds model was used for categorical variables (SW and 2PD tests and MCV stages). DASH score significantly improved by 6 months. Significant recovery in numbness and SW test scores occurred at 1 month. Grip and pinch strength, 2PD test scores, and MCV stage improved by 3 months. DASH scores and numbness recovered regardless of age, sex, or disease severity. It was still unclear if both subjective and objective measures improved beyond 1-year postoperatively. These data are helpful for predicting postoperative recovery patterns and tend to be most important for patients prior to surgery. PMID:27263860

  4. Postoperative improvement in DASH score, clinical findings, and nerve conduction velocity in patients with cubital tunnel syndrome.

    PubMed

    Ido, Yoshikazu; Uchiyama, Shigeharu; Nakamura, Koichi; Itsubo, Toshiro; Hayashi, Masanori; Hata, Yukihiko; Imaeda, Toshihiko; Kato, Hiroyuki

    2016-01-01

    We investigated a recovery pattern in subjective and objective measures among 52 patients with cubital tunnel syndrome after anterior subcutaneous transposition of the ulnar nerve. Disabilities of the Arm, Shoulder and Hand (DASH) score (primary outcome), numbness score, grip and pinch strength, Semmes-Weinstein (SW) score, static 2-point discrimination (2PD) score, and motor conduction velocity (MCV) stage were examined preoperatively and 1, 3, 6, 12, and ≥24 months postoperatively. Statistical analyses were conducted to evaluate how each variable improved after surgery. A linear mixed-effects model was used for continuous variables (DASH score, numbness, grip and pinch strength), and a proportional odds model was used for categorical variables (SW and 2PD tests and MCV stages). DASH score significantly improved by 6 months. Significant recovery in numbness and SW test scores occurred at 1 month. Grip and pinch strength, 2PD test scores, and MCV stage improved by 3 months. DASH scores and numbness recovered regardless of age, sex, or disease severity. It was still unclear if both subjective and objective measures improved beyond 1-year postoperatively. These data are helpful for predicting postoperative recovery patterns and tend to be most important for patients prior to surgery. PMID:27263860

  5. Effects of calcium antagonists on the alternation of the ST-T complex and associated conduction abnormalities during coronary occlusion in dogs.

    PubMed Central

    Hashimoto, H.; Nakashima, M.

    1981-01-01

    1 The effects of Ca2+ -antagonists on the relationships between alternate changes in the ST-T complex in the epicardial electrogram, ST-T alternans, and associated excitation-conduction abnormalities during coronary occlusion were examined in anaesthetized dogs. 2 Epicardial unipolar electrograms, bipolar electrograms (BPEG) and monophasic action potentials (MAP) were recorded with unipolar, composite and suction electrodes, respectively. 3 ST-T alternans was associated with serious conduction delay. During the period of ST-T alternans, the amplitude of MAP changed alternately and the negative deflection of the ST-T complex was associated with a larger MAP. A depression of the TQ level and decrease in the resting potential of MAP were marked. 4 Verapamil (0.2 mg/kg) and diltiazem (0.5 mg/kg) inhibited ST-T alternans, conduction abnormalities, TQ depression and changes in MAP. However, after these drugs, the TQ depression and the decrease in the resting potential were evident after a longer period of occlusion at a time when ST-T alternans, conduction abnormalities and alternate changes in MAP were still inhibited. Dipyridamole (0.5 mg/kg) had no effect on either ST-T alternans or the conduction abnormalities. 5 Verapamil and diltiazem inhibited ST-T alternans and the associated excitation and conduction abnormalities. The effects of these two drugs cannot be explained on the basis of attenuation of the decrease in the resting potential. PMID:7317686

  6. Effects of 90 min of manual repetitive work on skin temperature and median and ulnar nerve conduction parameters: a pilot study in normal subjects.

    PubMed

    Bonfiglioli, Roberta; Mussoni, Patrizia; Graziosi, Francesca; Calabrese, Monica; Farioli, Andrea; Marinelli, Francesco; Violante, Francesco S

    2013-02-01

    To test whether the influence of manual activity should be considered when interpreting the results of nerve conduction study (NCS) of the upper limbs performed during work shifts, we evaluated the short-term effect of 90-min repetitive manual work on NCS parameters. Twenty-eight healthy volunteers underwent NCS of the dominant limb at the end of an interview (T(0)), after a 30-min rest in sitting position (T(1)) and after performing a standardized 90-min manual task (T(2)). The task was designed to simulate typical assembly and packing activities. No significant differences were observed for skin temperature (Ts) and NCS parameters between T(0) and T(1). Significantly (p < 0.001) higher Ts mean values were found at T(2) as compared to the previous tests for both females and males. The regression analysis showed an association between temperature variation and nerve conduction velocity values for the median and ulnar nerve at T(2) as compared to T(1). In females, a reduction of the mean sensory nerve action potential (SNAP) amplitude at T(2) was recorded, whereas an opposite trend was observed among males. Manual work is able to influence hand Ts and to modify NCS parameters. SNAP amplitudes changes suggest gender differences in peripheral nerve characteristics that deserve further investigation.

  7. A novel large-conductance Ca(2+)-activated potassium channel and current in nerve terminals of the rat neurohypophysis.

    PubMed Central

    Wang, G; Thorn, P; Lemos, J R

    1992-01-01

    corresponds most closely to a Ca(2+)-activated K+ current (IK(Ca)) and not to a delayed rectifier or IA-like current. It also has properties different from that of the Ca(2+)-dependent outward current described in the magnocellular neuronal cell bodies of the hypothalamus. 8. A large conductance channel is often observed in isolated rat neurohypophysial nerve terminals. The channel had a unit conductance of 231 pS in symmetrical 150 mM K+.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:1284313

  8. Electrodiagnostic study of peripheral nerves in high-voltage electrical injury.

    PubMed

    Kwon, Ki Han; Kim, Se Hoon; Minn, Yang Ki

    2014-01-01

    It is well known that peripheral nerves are very vulnerable to electricity. However, only a small portion of individuals who have had high-voltage electrical injury exhibit peripheral nerve damage. The aim of this study was to investigate peripheral nerve damage in high-voltage electrical injury, which often occurs in the industrial field. The authors reviewed the medical records of patients who were admitted to their hospital from January 2009 to December 2011, because of electrical injuries. The results of nerve conduction studies (NCSs) were reviewed retrospectively. NCS data of the injured site were compared with those of the opposite noninjured site and follow-up data. Thirty-seven extremities were reviewed. The authors found that 18 of 33 median nerves (48.6%) showed abnormalities in at least one parameter and 15 of 36 ulnar nerves (41.7%) exhibited abnormalities. There was no evidence of demyelination. Eight patients had undergone NCS on the opposite normal extremities. The compound muscle action potential and nerve conduction velocity were higher at the normal site. Follow-up NCS were performed in 14 patients: the compound muscle action potential and nerve conduction velocity values of all patients were improved. High-voltage electricity damaged peripheral nerves by causing axonal injury rather than demyelinating injury. Hence, even if NCSs yield normal findings, peripheral nerves may be damaged. F/U studies and opposite examinations are required for the exact evaluation of peripheral nerve damage.

  9. Electrodiagnostic study of peripheral nerves in high-voltage electrical injury.

    PubMed

    Kwon, Ki Han; Kim, Se Hoon; Minn, Yang Ki

    2014-01-01

    It is well known that peripheral nerves are very vulnerable to electricity. However, only a small portion of individuals who have had high-voltage electrical injury exhibit peripheral nerve damage. The aim of this study was to investigate peripheral nerve damage in high-voltage electrical injury, which often occurs in the industrial field. The authors reviewed the medical records of patients who were admitted to their hospital from January 2009 to December 2011, because of electrical injuries. The results of nerve conduction studies (NCSs) were reviewed retrospectively. NCS data of the injured site were compared with those of the opposite noninjured site and follow-up data. Thirty-seven extremities were reviewed. The authors found that 18 of 33 median nerves (48.6%) showed abnormalities in at least one parameter and 15 of 36 ulnar nerves (41.7%) exhibited abnormalities. There was no evidence of demyelination. Eight patients had undergone NCS on the opposite normal extremities. The compound muscle action potential and nerve conduction velocity were higher at the normal site. Follow-up NCS were performed in 14 patients: the compound muscle action potential and nerve conduction velocity values of all patients were improved. High-voltage electricity damaged peripheral nerves by causing axonal injury rather than demyelinating injury. Hence, even if NCSs yield normal findings, peripheral nerves may be damaged. F/U studies and opposite examinations are required for the exact evaluation of peripheral nerve damage. PMID:23877148

  10. Effect of Enriched (Complex) Environment on Nerve Conduction Velocity: New Data and Review of Implications for the Speed of Information Processing.

    ERIC Educational Resources Information Center

    Reed, T. Edward

    1993-01-01

    Results with 54 mice confirm that increased stimulation or usage, as would be provided by environmental enrichment (EE), increases peripheral nerve conduction velocity. These results suggest a role at the physiological level for EE (or deprivation) in affecting measured intelligence. (SLD)

  11. Defects responsible for abnormal n-type conductivity in Ag-excess doped PbTe thermoelectrics

    SciTech Connect

    Ryu, Byungki Lee, Jae Ki; Lee, Ji Eun; Joo, Sung-Jae; Kim, Bong-Seo; Min, Bok-Ki; Lee, Hee-Woong; Park, Su-Dong; Oh, Min-Wook

    2015-07-07

    Density functional calculations have been performed to investigate the role of Ag defects in PbTe thermoelectric materials. Ag-defects can be either donor, acceptor, or isovalent neutral defect. When Ag is heavily doped in PbTe, the neutral (Ag-Ag) dimer defect at Pb-site is formed and the environment changes to the Pb-rich/Te-poor condition. Under Pb-rich condition, the ionized Ag-interstitial defect (Ag{sub I}{sup +}) becomes the major donor. The formation energy of Ag{sub I}{sup +} is smaller than other native and Ag-related defects. Also it is found that Ag{sub I}{sup +} is an effective dopant. There is no additional impurity state near the band gap and the conduction band minimum. The charge state of Ag{sub I}{sup +} defect is maintained even when the Fermi level is located above the conduction band minimum. The diffusion constant of Ag{sub I}{sup +} is calculated based on the temperature dependent Fermi level, formation energy, and migration energy. When T > 550 K, the diffusion length of Ag within a few minutes is comparable to the grain size of the polycrystalline PbTe, implying that Ag is dissolved into PbTe and this donor defect is distributed over the whole lattice in Ag-excess doped polycrystalline PbTe. The predicted solubility of Ag{sub I}{sup +} well explains the increased electron carrier concentration and electrical conductivity reported in Ag-excess doped polycrystalline PbTe at T = 450–750 K [Pei et al., Adv. Energy Mater. 1, 291 (2011)]. In addition, we suggest that this abnormal doping behavior is also found for Au-doped PbTe.

  12. Diagnostic Significance of Ultrasonographic Measurements and Median-Ulnar Ratio in Carpal Tunnel Syndrome: Correlation with Nerve Conduction Studies

    PubMed Central

    Mesci, Nilgün; Çetinkaya, Yilmaz; Geler Külcü, Duygu

    2016-01-01

    Background and Purpose We determined the reliability of ultrasonography (US) measurements for diagnosing carpal tunnel syndrome (CTS) and their correlation with symptom duration and electrophysiology findings. We determined whether the ratio of the median-to-ulnar cross-sectional areas (CSAs) can support CTS diagnoses. Methods The pisiform CSA (CSApisiform), swelling ratio (SR), palmar bowing, and CSApisiform/ulnar CSA (CSAulnar) measurements made in two subgroups of CTS patients (having sensory affection alone or having both sensory and motor affection) were compared with controls. CSAulnar was measured in Guyon's canal at the level of most-protuberant portion of the pisiform bone. Results The values of all of the measured US parameters were higher in patients with CTS (n=50) than in controls (n=62). CSApisiform could be used to diagnose CTS of mild severity. All of the parameters were positively correlated with the distal latency of the compound muscle action potential, and all of them except for SR were negatively correlated with the sensory nerve conduction velocity. A CSApisiform/CSAulnar ratio of ≥1.79 had a sensitivity of 70% and a specificity of 76% for diagnosing CTS. Conclusions Only CSApisiform measurements were reliable for diagnosing early stages of CTS, and CSApisiform/CSAulnar had a lower diagnostic value for diagnosing CTS. PMID:27095524

  13. A novel NF1 mutation in a Chinese patient with giant café-au-lait macule in neurofibromatosis type 1 associated with a malignant peripheral nerve sheath tumor and bone abnormality.

    PubMed

    Tong, H-X; Li, M; Zhang, Y; Zhu, J; Lu, W-Q

    2012-08-29

    Neurofibromatosis type 1 (NF1; OMIM#162200) is a common neurocutaneous disorder that is characterized by multiple café-au-lait, skinfold freckling, Lisch nodules, and neurofibromas. Mutations in the NF1 gene, which encodes the neurofibromin protein, have been identified as the pathogenic gene of NF1. In this study, we present a clinical and molecular study of a Chinese patient with giant café-au-lait in NF1. The patient showed >6 café-au-lait spots on the body, axillary freckling, and multiple subcutaneous neurofibromas. He also had a malignant peripheral nerve sheath tumor and bone abnormalities. The germline mutational analysis of the NF1 gene revealed a novel missense mutation in exon 13. It is a novel heterozygous nucleotide G>A transition at position 2241 of the NF1 gene. We found no mutation in malignant peripheral nerve sheath tumor DNA from this patient. This expands the database for NF1 gene mutations in NF1. Its absence in the normal chromosomes suggests that it is responsible for the NF1 phenotype. To our knowledge, this is the first case of giant café-au-lait macule in NF1 associated with a malignant peripheral nerve sheath tumor and bone abnormality.

  14. Heart rate, conduction and ultrasound abnormalities in adults with joint hypermobility syndrome/Ehlers-Danlos syndrome, hypermobility type.

    PubMed

    Camerota, Filippo; Castori, Marco; Celletti, Claudia; Colotto, Marco; Amato, Silvia; Colella, Alessandra; Curione, Mario; Danese, Chiara

    2014-07-01

    Joint hypermobility syndrome (JHS) and Ehlers-Danlos syndrome, hypermobility type (EDS-HT) are two clinically overlapping heritable connective tissue disorders strongly associating with pain, fatigue and other secondary aspects. Though not considered a diagnostic criterion for most EDS subtypes, cardiovascular involvement is a well-known complication in EDS. A case-control study was carried out on 28 adults with JHS/EDS-HT diagnosed according to current criteria, compared to 29 healthy subjects evaluating resting electrocardiographic (ECG), 24-h ECG and resting heart ultrasound data. Results obtained in the ECG studies showed a moderate excess in duration of the PR interval and P wave, an excess of heart conduction and rate abnormalities and an increased rate of mitral and tricuspid valve insufficiency often complicating with "true" mitral valve prolapse in the ecocardiographic study. These variable ECG subclinical anomalies reported in our sample may represent the resting surrogate of such a subnormal cardiovascular response to postural changes that are known to be present in patients with JHS/EDS-HT. Our findings indicate the usefulness of a full cardiologic evaluation of adults with JHS/EDS-HT for the correct management. PMID:24752348

  15. Peripheral nerve injuries in the athlete.

    PubMed

    Feinberg, J H; Nadler, S F; Krivickas, L S

    1997-12-01

    Peripheral nerves are susceptible to injury in the athlete because of the excessive physiological demands that are made on both the neurological structures and the soft tissues that protect them. The common mechanisms of injury are compression, traction, ischaemia and laceration. Seddon's original classification system for nerve injuries based on neurophysiological changes is the most widely used. Grade 1 nerve injury is a neuropraxic condition, grade 2 is axonal degeneration and grade 3 is nerve transection. Peripheral nerve injuries are more common in the upper extremities than the lower extremities, tend to be sport specific, and often have a biomechanical component. While the more acute and catastrophic neurological injuries are usually obvious, many remain subclinical and are not recognised before neurological damage is permanent. Early detection allows initiation of a proper rehabilitation programme and modification of biomechanics before the nerve injury becomes irreversible. Recognition of nerve injuries requires an understanding of peripheral neuroanatomy, knowledge of common sites of nerve injury and an awareness of the types of peripheral nerve injuries that are common and unique to each sport. The electrodiagnostic exam, usually referred to as the 'EMG', consists of nerve conduction studies and the needle electrode examination. It is used to determine the site and degree of neurological injury and to predict outcome. It should be performed by a neurologist or physiatrist (physician specialising in physical medicine and rehabilitation), trained and skilled in this procedure. Timing is essential if the study is to provide maximal information. Findings such as decreased recruitment after injury and conduction block at the site of injury may be apparent immediately after injury but other findings such as abnormal spontaneous activity may take several weeks to develop. The electrodiagnostic test assists with both diagnosis of the injury and in predicting

  16. Partial nerve injury induces electrophysiological changes in conducting (uninjured) nociceptive and nonnociceptive DRG neurons: Possible relationships to aspects of peripheral neuropathic pain and paresthesias

    PubMed Central

    Djouhri, Laiche; Fang, Xin; Koutsikou, Stella; Lawson, Sally N.

    2012-01-01

    Partial nerve injury leads to peripheral neuropathic pain. This injury results in conducting/uninterrupted (also called uninjured) sensory fibres, conducting through the damaged nerve alongside axotomised/degenerating fibres. In rats seven days after L5 spinal nerve axotomy (SNA) or modified-SNA (added loose-ligation of L4 spinal nerve with neuroinflammation-inducing chromic-gut), we investigated a) neuropathic pain behaviours and b) electrophysiological changes in conducting/uninterrupted L4 dorsal root ganglion (DRG) neurons with receptive fields (called: L4-receptive-field-neurons). Compared to pretreatment, modified-SNA rats showed highly significant increases in spontaneous-foot-lifting duration, mechanical-hypersensitivity/allodynia, and heat-hypersensitivity/hyperalgesia, that were significantly greater than after SNA, especially spontaneous-foot-lifting. We recorded intracellularly in vivo from normal L4/L5 DRG neurons and ipsilateral L4-receptive-field-neurons. After SNA or modified-SNA, L4-receptive-field-neurons showed the following: a) increased percentages of C-, Ad-, and Ab-nociceptors and cutaneous Aa/b-low-threshold mechanoreceptors with ongoing/spontaneous firing; b) spontaneous firing in C-nociceptors that originated peripherally; this was at a faster rate in modified-SNA than SNA; c) decreased electrical thresholds in A-nociceptors after SNA; d) hyperpolarised membrane potentials in A-nociceptors and Aa/b-low-threshold-mechanoreceptors after SNA, but not C-nociceptors; e) decreased somatic action potential rise times in C- and A-nociceptors, not Aa/b-low-threshold-mechanoreceptors. We suggest that these changes in subtypes of conducting/uninterrupted neurons after partial nerve injury contribute to the different aspects of neuropathic pain as follows: spontaneous firing in nociceptors to ongoing/spontaneous pain; spontaneous firing in Aa/b-low-threshold-mechanoreceptors to dysesthesias/paresthesias; and lowered A-nociceptor electrical thresholds

  17. Ventricular conduction abnormalities as predictors of long‐term survival in acute de novo and decompensated chronic heart failure

    PubMed Central

    Siirila‐Waris, Krista; Harjola, Veli‐Pekka; Marono, David; Parenica, Jiri; Kreutzinger, Philipp; Nieminen, Tuomo; Pavlusova, Marie; Tarvasmaki, Tuukka; Twerenbold, Raphael; Tolonen, Jukka; Miklik, Roman; Nieminen, Markku S.; Spinar, Jindrich; Mueller, Christian; Lassus, Johan

    2016-01-01

    Abstract Aims Data on the prognostic role of left and right bundle branch blocks (LBBB and RBBB), and nonspecific intraventricular conduction delay (IVCD; QRS ≥ 110 ms, no BBB) in acute heart failure (AHF) are controversial. Our aim was to investigate electrocardiographic predictors of long‐term survival in patients with de novo AHF and acutely decompensated chronic heart failure (ADCHF). Methods and Results We analysed the admission electrocardiogram of 982 patients from a multicenter European cohort of AHF with 3.9 years' mean follow‐up. Half (51.5%, n = 506) of the patients had de novo AHF. LBBB, and IVCD were more common in ADCHF than in de novo AHF: 17.2% vs. 8.7% (P < 0.001) and 20.6% vs. 13.2% (P = 0.001), respectively, and RBBB was almost equally common (6.9% and 8.1%; P = 0.5), respectively. Mortality during the follow‐up was higher in patients with RBBB (85.4%) and IVCD (73.7%) compared with patients with normal ventricular conduction (57.0%); P < 0.001 for both. The impact of RBBB on prognosis was prominent in de novo AHF (adjusted HR 1.93, 1.03–3.60; P = 0.04), and IVCD independently predicted death in ADCHF (adjusted HR 1.79, 1.28–2.52; P = 0.001). Both findings were pronounced in patients with reduced ejection fraction. LBBB showed no association with increased mortality in either of the subgroups. The main results were confirmed in a validation cohort of 1511 AHF patients with 5.9 years' mean follow‐up. Conclusions Conduction abnormalities predict long‐term survival differently in de novo AHF and ADCHF. RBBB predicts mortality in de novo AHF, and IVCD in ADCHF. LBBB has no additive predictive value in AHF requiring hospitalization.

  18. Altered Active Zones, Vesicle Pools, Nerve Terminal Conductivity, and Morphology during Experimental MuSK Myasthenia Gravis

    PubMed Central

    Patel, Vishwendra; Oh, Anne; Voit, Antanina; Sultatos, Lester G.; Babu, Gopal J.; Wilson, Brenda A.; Ho, Mengfei; McArdle, Joseph J.

    2014-01-01

    Recent studies demonstrate reduced motor-nerve function during autoimmune muscle-specific tyrosine kinase (MuSK) myasthenia gravis (MG). To further understand the basis of motor-nerve dysfunction during MuSK-MG, we immunized female C57/B6 mice with purified rat MuSK ectodomain. Nerve-muscle preparations were dissected and neuromuscular junctions (NMJs) studied electrophysiologically, morphologically, and biochemically. While all mice produced antibodies to MuSK, only 40% developed respiratory muscle weakness. In vitro study of respiratory nerve-muscle preparations isolated from these affected mice revealed that 78% of NMJs produced endplate currents (EPCs) with significantly reduced quantal content, although potentiation and depression at 50 Hz remained qualitatively normal. EPC and mEPC amplitude variability indicated significantly reduced number of vesicle-release sites (active zones) and reduced probability of vesicle release. The readily releasable vesicle pool size and the frequency of large amplitude mEPCs also declined. The remaining NMJs had intermittent (4%) or complete (18%) failure of neurotransmitter release in response to 50 Hz nerve stimulation, presumably due to blocked action potential entry into the nerve terminal, which may arise from nerve terminal swelling and thinning. Since MuSK-MG-affected muscles do not express the AChR γ subunit, the observed prolongation of EPC decay time was not due to inactivity-induced expression of embryonic acetylcholine receptor, but rather to reduced catalytic activity of acetylcholinesterase. Muscle protein levels of MuSK did not change. These findings provide novel insight into the pathophysiology of autoimmune MuSK-MG. PMID:25438154

  19. A transgenic zebrafish model of a human cardiac sodium channel mutation exhibits bradycardia, conduction-system abnormalities and early death.

    PubMed

    Huttner, Inken G; Trivedi, Gunjan; Jacoby, Arie; Mann, Stefan A; Vandenberg, Jamie I; Fatkin, Diane

    2013-08-01

    The recent exponential increase in human genetic studies due to the advances of next generation sequencing has generated unprecedented numbers of new gene variants. Determining which of these are causative of human disease is a major challenge. In-vitro studies and murine models have been used to study inherited cardiac arrhythmias but have several limitations. Zebrafish models provide an attractive alternative for modeling human heart disease due to similarities in cardiac electrophysiology and contraction, together with ease of genetic manipulation, external development and optical transparency. Although zebrafish cardiac mutants and morphants have been widely used to study loss and knockdown of zebrafish gene function, the phenotypic effects of human dominant-negative gene mutations expressed in transgenic zebrafish have not been evaluated. The aim of this study was to generate and characterize a transgenic zebrafish arrhythmia model harboring the pathogenic human cardiac sodium channel mutation SCN5A-D1275N, that has been robustly associated with a range of cardiac phenotypes, including conduction disease, sinus node dysfunction, atrial and ventricular arrhythmias, and dilated cardiomyopathy in humans and in mice. Stable transgenic fish with cardiac expression of human SCN5A were generated using Tol2-mediated transgenesis and cardiac phenotypes were analyzed using video microscopy and ECG. Here we show that transgenic zebrafish expressing the SCN5A-D1275N mutation, but not wild-type SCN5A, exhibit bradycardia, conduction-system abnormalities and premature death. We furthermore show that SCN5A-WT, and to a lesser degree SCN5A-D1275N, are able to compensate the loss of endogenous zebrafish cardiac sodium channels, indicating that the basic pathways, through which SCN5A acts, are conserved in teleosts. This proof-of-principle study suggests that zebrafish may be highly useful in vivo models to differentiate functional from benign human genetic variants in cardiac

  20. The Effect of the Silicone Ring Tourniquet and Standard Pneumatic Tourniquet on the Motor Nerve Conduction, Pain and Grip Strength in Healthy Volunteers

    PubMed Central

    Drosos, Georgios I.; Kiziridis, Georgios; Aggelopoulou, Cristina; Galiatsatos, Dimitrios; Anastassopoulos, George; Ververidis, Athanasios; Kazakos, Konstantinos

    2016-01-01

    Background: The pneumatic tourniquet (PT) is routinely used in upper and lower limb operations by most orthopaedic surgeons. The silicone ring tourniquet (SRT) was introduced in clinical practice over the last decade. Clinical as well as comparative studies have been published in volunteers concerning its safety and efficacy. The aim of this study was to investigate the postoperative effect of the silicone ring tourniquet (SRT), primarily on the motor nerve conduction, and secondarily on the pain and grip strength, in comparison to the effect of the pneumatic tourniquet (PT) in healthy volunteers. Methods: Both tourniquets were applied in the forearm of the dominant arm in 20 healthy volunteers and were kept on for 10 minutes. Pain was measured using the visual analogue scale and grip strength was measured with a hand dynamometer. We evaluated the following parameters of median nerve conduction: motor conduction velocity (MCV), latency (LAT) and amplitude (AMP). Results: Pain score at the time of tourniquet application was higher in SRT group but the alteration in pain scores in PT group was higher, with statistical significance (P<0.05). The grip strength was reduced by the application of both tourniquets; however there was a significantly higher reduction in the SRT group (P<0.05). The conduction impairment of the median nerve was worse in the PT group than in the SRT one, according to the changes in MCV (P<0.05). Conclusion: Median nerve conduction was affected more after PT application as compared to the SRT. Nevertheless, the reduction of grip strength was higher after the SRT application. PMID:26894213

  1. Amplitude of sensory nerve action potential in early stage diabetic peripheral neuropathy: an analysis of 500 cases.

    PubMed

    Zhang, Yunqian; Li, Jintao; Wang, Tingjuan; Wang, Jianlin

    2014-07-15

    Early diagnosis of diabetic peripheral neuropathy is important for the successful treatment of diabetes mellitus. In the present study, we recruited 500 diabetic patients from the Fourth Affiliated Hospital of Kunming Medical University in China from June 2008 to September 2013: 221 cases showed symptoms of peripheral neuropathy (symptomatic group) and 279 cases had no symptoms of peripheral impairment (asymptomatic group). One hundred healthy control subjects were also recruited. Nerve conduction studies revealed that distal motor latency was longer, sensory nerve conduction velocity was slower, and sensory nerve action potential and amplitude of compound muscle action potential were significantly lower in the median, ulnar, posterior tibial and common peroneal nerve in the diabetic groups compared with control subjects. Moreover, the alterations were more obvious in patients with symptoms of peripheral neuropathy. Of the 500 diabetic patients, neural conduction abnormalities were detected in 358 cases (71.6%), among which impairment of the common peroneal nerve was most prominent. Sensory nerve abnormality was more obvious than motor nerve abnormality in the diabetic groups. The amplitude of sensory nerve action potential was the most sensitive measure of peripheral neuropathy. Our results reveal that varying degrees of nerve conduction changes are present in the early, asymptomatic stage of diabetic peripheral neuropathy.

  2. Role of cardiotoxin and phospholipase A in the blockade of nerve conduction and depolarization of skeletal muscle induced by cobra venom

    PubMed Central

    Chang, C. C.; Chuang, Sing-Tai; Lee, C. Y.; Wei, J. W.

    1972-01-01

    1. The effects of phospholipase A (PhA), cardiotoxin (CTX) and neurotoxin (cobrotoxin) isolated from Formosan cobra (Naja naja atra) venom on conduction of the rat phrenic nerve and membrane potential of the rat diaphragm were studied. 2. Phospholipase A, lysolecithin and cobrotoxin were without effect on the axonal conduction. Cardiotoxin was the only active agent in cobra venom, but it was less potent than the crude venom. 3. The blocking action of cardiotoxin was markedly accelerated by the simultaneous administration of phospholipase A. However, the minimum effective concentration of cardiotoxin (100 μg/ml), was not decreased by phospholipase A. Pretreatment of the nerve with phospholipase A, followed by washout, did not alter the activity of cardiotoxin. 4. Cardiotoxin (3 μg/ml) completely depolarized the membrane of superficial muscle fibres within 60 min, being 3 times more potent than the crude venom. Phospholipase A, on the other hand, needed a dose 30 times higher and a prolonged period of incubation to induce depolarization of similar extent. Cobrotoxin was without effect on membrane potentials. 5. CaCl2 (10 mM) effectively antagonized the nerve blocking as well as the depolarizing effect of the crude venom, cardiotoxin or cardiotoxin plus phospholipase A. By contrast, the slow depolarizing effect of phospholipase A was enhanced by high concentrations of calcium. 6. Cardiotoxic fractions of Indian cobra venom affected both nerve conduction and diaphragm membrane potential in exactly the same way as cardiotoxin. Toxin A of the same venom was without effect. 7. It is concluded that the active agent in cobra venoms either on axonal conduction or on muscle membrane is cardiotoxin. The synergistic effect of phospholipase A on cardiotoxin appears to be due to acceleration rather than potentiation of its action. The mechanism of action of cardiotoxin and its synergism by phospholipase A are discussed. PMID:5041453

  3. Effects of Acute Organophosphorus Poisoning on Function of Peripheral Nerves: A Cohort Study

    PubMed Central

    Jayasinghe, Sudheera S.; Pathirana, Kithsiri D.; Buckley, Nick A.

    2012-01-01

    Background Following acute organophosphorus (OP) poisoning patients complain of numbness without objective sensory abnormalities or other features of OP induced delayed polyneuropathy. The aim of this study was to measure peripheral nerve function after acute exposure to OP. Methods A cohort study was conducted with age, gender and occupation matched controls. Motor nerve conduction velocity (MNCV), amplitude and area of compound muscle action potential (CMAP), sensory nerve conduction velocity (SNCV), F- waves and electromyography (EMG) on the deltoid and the first dorsal interosseous muscles on the dominant side were performed, following acute OP poisoning. All neurophysiological assessments except EMG were performed on the controls. Assessments were performed on the day of discharge from the hospital (the first assessment) and six weeks (the second assessment) after the exposure. The controls were assessed only once. Results There were 70 patients (50 males) and 70 controls. Fifty-three patients attended for the second assessment. In the first assessment MNCV of all the motor nerves examined, CMAP amplitude and SNCV of ulnar nerve, median and ulnar F-wave occurrence in the patients were significantly reduced compared to the controls. In the second assessment significant reduction was found in SNCV of both sensory nerves examined, MNCV of ulnar nerve, CMAP amplitude of common peroneal nerve, F-wave occurrence of median and ulnar nerves. No abnormalities were detected in the patients when compared to the standard cut-off values of nerve conduction studies except F-wave occurrence. EMG studies did not show any abnormality. Conclusion There was no strong evidence of irreversible peripheral nerve damage following acute OP poisoning, however further studies are required. PMID:23185328

  4. Normalization of sonographical multifocal nerve enlargements in a MADSAM patient following a good clinical response to intravenous immunoglobulin.

    PubMed

    Tanaka, Kanta; Ota, Natsuko; Harada, Yuzuru; Wada, Ikko; Suenaga, Toshihiko

    2016-09-01

    Focal nerve enlargements at sites of conduction blocks can be visualized sonographically in patients with multifocal acquired demyelinating sensory and motor neuropathy (MADSAM). However, little is known about association between nerve morphological changes and treatment responses. Here we present a 73-year-old female MADSAM patient whose sonographical multifocal nerve enlargements normalized following a good treatment response. She was admitted to our department with progressive asymmetrical muscle weakness and sensory disturbances for 6 months. Ultrasonography revealed multifocal nerve enlargements at sites of electrophysiological demyelination. Intravenous immunoglobulin improved her symptoms and electrophysiological abnormalities. Six months later, ultrasonography revealed normalization of multifocal nerve enlargements. Contrary to our observations, one previous report described a MADSAM patient with persistent nerve enlargements at the sites of resolved conduction blocks. In this earlier patient, however, the time from onset to remission was approximately 30 months. Morphological changes of nerve enlargements in MADSAM may vary with treatment response. PMID:27460345

  5. Effects of pyrethroid molecules on rat nerves in vitro: potential to reverse temperature-sensitive conduction block of demyelinated peripheral axons

    PubMed Central

    Lees, George

    1998-01-01

    Prolongation of action potentials by cooling or pharmacological treatment can restore conduction in demyelinated axons. We have assessed the ability of pyrethroids (in vitro) to modify action potential kinetics and to reverse conduction block in lesioned peripheral nerve. Fast Na+ currents were isolated in mammalian neuroblastoma (NIE115). Pyrethroids (4 μM) concurrently slowed inactivation and produced a spectrum of pronounced tail currents: s-bioallethrin (duration 12.2±7 ms), permethrin (24.2±3 ms) and deltamethrin (2230±100 ms). Deltamethrin (5 μM) effected a slowly developing depression of compound action potential (CAP) amplitude in peroneal nerve trunks (P<0.05). Permethrin produced no net effect on CAP amplitude, area or repolarization time. s-Bioallethrin (5 μM) enhanced CAP area, time for 90% repolarization and induced regenerative activity in a subpopulation of axons. Tibial nerve trunks were demyelinated by lysolecithin (2 μl) injection: 6–14 days later, slowly-conducting axons in the CAP (and peri-axonal microelectrode recordings) were selectively blocked by warming to 37°C. At 37°C, s-bioallethrin (45 min, 5 μM) produced much greater after-potentials in lesioned nerves than in uninjected controls: area (P<0.05) and relative amplitude ratios (P<0.0001) were significantly altered. In 3 of 4 cells (single-unit recording), s-bioallethrin restored conduction through axons exhibiting temperature-dependent block by raising blocking temperature (by 1.5 to >3°C) and reducing refractory period. s-Bioallethrin induced temperature-dependent regenerative activity only in a sub-population of axons even after prolonged superfusion (>1 h). It was concluded that pyrethroids differentially alter Na+ current kinetics and action potential kinetics. The effects of s-bioallethrin are consistent with reversal of conduction block by demyelinated axons but regenerative/ectopic firing even in normal cells is likely to underpin its acknowledged

  6. Lower cranial nerves.

    PubMed

    Soldatos, Theodoros; Batra, Kiran; Blitz, Ari M; Chhabra, Avneesh

    2014-02-01

    Imaging evaluation of cranial neuropathies requires thorough knowledge of the anatomic, physiologic, and pathologic features of the cranial nerves, as well as detailed clinical information, which is necessary for tailoring the examinations, locating the abnormalities, and interpreting the imaging findings. This article provides clinical, anatomic, and radiological information on lower (7th to 12th) cranial nerves, along with high-resolution magnetic resonance images as a guide for optimal imaging technique, so as to improve the diagnosis of cranial neuropathy.

  7. Impaired sensory conduction in a mixed nerve induced by high frequency stimulation of the muscle fibres. An experimental study in cats.

    PubMed

    Miyauchi, A; Matsuda, H; Shimazu, A; Nakata, N; Seki, M

    1993-12-01

    To see if symptoms such as sensory disturbance or numbness worsen during exercise as is thought to occur in entrapment neuropathy, we studied the interaction between sensory and muscle nerve fibres in a mixed nerve in cats. Stimulation electrodes were placed on both the deep (muscle) and superficial (sensory) branch of the radial nerve at the elbow. High frequency stimulation at 100 Hz was applied to one branch for five minutes and the nerve action potential of the other branch was recorded at the axilla where the radial nerve is mixed. The stimulation decreased the amplitude of the nerve action potential and prolonged its latency. Recovery from these changes was gradual, and changes were the same whichever branch was stimulated. When a cat's leg was made ischaemic, the changes were more pronounced. The changes in the nerve action potential may have arisen from ischaemia in the nerve, possibly caused by high frequency stimulation. PMID:8159937

  8. Longitudinal changes of nerve conduction velocity, distal motor latency, compound motor action potential duration, and skin temperature during prolonged exposure to cold in a climate chamber.

    PubMed

    Maetzler, Walter; Klenk, Jochen; Becker, Clemens; Zscheile, Julia; Gabor, Kai-Steffen; Lindemann, Ulrich

    2012-09-01

    Changes of nerve conduction velocity (NCV), distal motor latency (DML), compound motor action potential (CMAP) duration, and skin temperature with regard to cold have been investigated by use of ice packs or cold water baths, but not after cooling of environmental temperature which has higher ecological validity. The aim of this study was to investigate these parameters during cooled room temperature. NCV, DML, and CMAP duration of the common fibular nerve, and skin temperature were measured in 20 healthy young females during exposure to 15°C room temperature, coming from 25°C room. We found that NCV decreased and DML increased linearly during 45 min observation time, in contrast to CMAP duration and skin temperature which changes followed an exponential curve. To the best of our knowledge, this is the first study investigating changes of these parameters during exposure to environmental cold. The results may pilot some new hypotheses and studies on physiological and pathological changes of the peripheral nervous system and skin to environmental cold, e.g., in elderly with peripheral neuropathies. PMID:22510085

  9. Autonomic nervous system dysfunction in workers exposed to lead, zinc, and copper in relation to peripheral nerve conduction: a study of R-R interval variability

    SciTech Connect

    Murata, K.; Araki, S. )

    1991-01-01

    Quantitative assessment of the autonomic neurotoxicity due to lead was undertaken by measuring variability in the electrocardiographic R-R interval (CVRR) in 16 male workers exposed to lead, zinc, copper, and tin and in 16 unexposed control subjects. Two component coefficients of variation in the R-R interval, the C-CVRSA (respiratory sinus arrhythmia) and C-CVMWSA (Mayer wave related sinus arrhythmia), were examined; these indices are considered to reflect parasympathetic and sympathetic activities, respectively. Maximal motor and sensory conduction velocities (MCV and SCV) in the median nerve were also measured. In the 16 exposed workers, blood lead concentrations ranged from 16 to 60 (mean 34) micrograms/dl. The CVRR and C-CVRSA were found to be significantly reduced in the workers with elevated lead, zinc, and copper absorption as compared to unexposed control subjects; also, the MCV and SCV were significantly slowed. The C-CVMWSA was not significantly reduced, and was positively related to plasma zinc concentrations. No significant relationships were found between indicators of lead and copper absorption and these electrophysiological measurements. These data suggest that subclinical toxicity of lead occurs in the parasympathetic component of the autonomic nervous system as well as in the peripheral nerves. Zinc may antagonize the autonomic nervous dysfunction caused by lead.

  10. Functional end-plate recovery in long-term botulinum toxin therapy of hemifacial spasm: a nerve conduction study.

    PubMed

    Butera, C; Guerriero, R; Amadio, S; Ungaro, D; Tesfaghebriel, H; Bianchi, F; Comi, G; Del Carro, U

    2013-02-01

    Botulinum toxin type-A is currently thought to be effective and safe for hemifacial spasm (HFS). The pre-synaptic block of acetylcholine release at the neuromuscular junction induces depression of orbicularis oculi muscle compound motor action potential (CMAP). The aim of our study was to evaluate at what extent end-plate functional recovery is possible even in botulinum toxin treatments lasting up to 15 years. We examined 81 outpatients with primary HFS (mean treatment duration = 7.2 ± 4.2 years) who underwent neurophysiologic study, once clinical effect of the previous treatment had vanished. The mean CMAP amplitude, mean rectified amplitude of response 1 (R1) of the blink reflex and area of response 2 (R2) of treated orbicularis oculi muscle were measured in comparison to the controlateral side. Mean amplitude of the above mentioned parameters was slightly lower (about 20%; p < 0.001) in the treated side at the end of the follow-up period (4.7 ± 1.7 months). The CMAP amplitude reduction weakly correlated with the interval from last treatment, while other neurophysiologic parameters did not change due to treatment duration or total toxin amount. Our study demonstrates that botulinum toxin affects compound motor action potential and blink-reflex responses for at least 4-5 months in HFS patients. The residual block is slight and does not increase with repeated injections after several years of treatment. Our study, beside confirming the long-term efficacy of botulinum toxin treatment for HFS, provides neurophysiologic evidence that therapeutic effect may be obtained without hindering the regenerative potential of the nerve-muscle complex.

  11. Cellular mechanism of the conduction abnormalities induced by serum from anti-Ro/SSA-positive patients in rabbit hearts.

    PubMed Central

    Garcia, S; Nascimento, J H; Bonfa, E; Levy, R; Oliveira, S F; Tavares, A V; de Carvalho, A C

    1994-01-01

    In this study, IgG fractions from sera of SLE patients with anti-Ro/SSA or anti-Ro/SSA and anti-La/SSB activity were tested in Langendorff preparations of adult rabbit hearts, aiming to reproduce the cardiac manifestations observed in neonatal lupus in an experimental model. The hearts were perfused with normal Tyrode's solution for 30 min, followed by perfusion with Tyrode's containing 0.3 mg/ml of anti-Ro/SSA- (or anti-Ro/La-) positive IgG (nine sera), anti-ribonucleoprotein (RNP)-positive IgG (five sera), or IgG fractions from normal donors (five sera). In one third of the experiments done with anti-Ro/La-positive IgG, heart block was observed. With the remaining fractions, a decrease in heart rate of 17.1% was observed, but normal sinus rhythm was maintained. The IgG fractions with anti-RNP activity (five experiments) and from normal sera (six experiments) reduced heart rates by 12.9 and 3.3%, respectively, but heart block was not observed. To further characterize the cellular mechanisms involved in the conduction disturbances observed in the whole rabbit hearts, we conducted experiments with ventricular myocytes isolated from young rabbit hearts, studied by whole cell patch-clamp technique. In these experiments, the slow inward currents were analyzed during the superfusion of the cell with normal Tyrode's solution and 5 min after superfusion with Tyrode's solution containing 0.3 mg/ml of anti-Ro/SSA- (or anti-Ro/La-) positive IgG (five sera), anti-RNP-positive IgG (three sera), or IgG from normal donors (four sera). Resting and action potential amplitudes were not affected by any of the sera used. The anti-Ro/SSA IgG fraction induced a mean reduction in the peak slow inward current of 31.6%. IgG fractions with anti-RNP activity reduced slow inward current by 4.4%, whereas IgG fractions from normal donors increased this current by 3.3%. IgG-free fractions from sera of patients with anti-Ro/SSA activity did not alter the peak slow inward current. These results

  12. Evaluation of left atrial mechanical function and atrial conduction abnormalities in Maras powder (smokeless tobacco) users and smokers

    PubMed Central

    Akcay, Ahmet; Naci Aydin, M; Acar, Gurkan; Akgungor, Mehmet; Cabioglu, Eren; Ardic, İdris; Mese, Bulent; Bozoglan, Orhan; Çetin, Mustafa; Çakıcı, Musa

    2015-01-01

    Summary Objective In Turkey, a type of smokeless tobacco called Maras powder (MP) is widely used in the south-eastern region. Smokeless tobacco is found in preparations for chewing and for absorption by the nasal and oral mucosae. The purpose of this study was to investigate whether MP damages intra- and inter-atrial conduction delay and left atrial (LA) mechanical function as much as cigarette smoking. Method A total of 150 chronic MP users (50 males, 32.5 ± 5.4 years), smokers (50 males, 32.1 ± 6.0 years) and controls (50 males, 30.1 ± 5.8 years) were included in the study. LA volumes were measured echocardiographically according to the biplane area–length method. Atrial electromechanical coupling was measured with tissue Doppler imaging and LA mechanical function parameters were calculated. Results The LA passive emptying fraction was significantly decreased and LA active emptying volume (LAAEV) was significantly increased in the MP group (p = 0.012 and p = 0.024, respectively), and the LA active emptying fraction (LAAEF) was significantly increased in the smokers (p = 0.003). There was a positive correlation between the amount of MP used and smoking (pack years) with LAAEV and LAAEF (r = 0.26, p = 0.009 and r = 0.25, p = 0.013, respectively). Lateral atrial electromechanical intervals (PA) were significantly higher in MP users, and the septal mitral PA was statistically higher in the smokers (p = 0.05 and p = 0.04, respectively). Conclusion We suggest that atrial electromechanical coupling intervals were prolonged and LA mechanical function was impaired in MP users and smokers, but there was no significant difference between the MP users and smokers. These findings may be markers of subclinical cardiac involvement and tendency for atrial fibrillation. PMID:26592906

  13. Facial nerve dysfunction in hereditary motor and sensory neuropathy type I and III.

    PubMed

    Glocker, F X; Rösler, K M; Linden, D; Heinen, F; Hess, C W; Lücking, C H

    1999-09-01

    Facial nerve function was studied in 19 patients with hereditary motor and sensory neuropathy type I (HMSN I) and 2 patients with hereditary motor and sensory neuropathy type III (HMSN III, Déjérine-Sottas), and compared to that in 24 patients with Guillain-Barré syndrome (GBS). The facial nerve was stimulated electrically at the stylomastoid fossa, and magnetically in its proximal intracanalicular segment. Additionally, the face-associated motor cortex was stimulated magnetically. The facial nerve motor neurography was abnormal in 17 of 19 HMSN I patients and in both HMSN III patients, revealing moderate to marked conduction slowing in both the extracranial and intracranial nerve segments, along with variable reductions of compound muscle action potential (CMAP) amplitudes. The facial nerve conduction slowing paralleled that of limb nerves, but was not associated with clinical dysfunction of facial muscles, because none of the HMSN I patients had facial palsy. Conduction slowing was most severe in the HMSN III patients, but only slight facial weakness was present. In GBS, conduction slowing was less marked, but facial weakness exceeded that in HMSN patients in all cases. We conclude that involvement of the facial nerve is common in HMSN I and HMSN III. It affects the intra- and extracranial part of the facial nerve and is mostly subclinical. PMID:10454715

  14. Cystic fibrosis transmembrane conductance regulator (CFTR) gene abnormalities in Indian males with congenital bilateral absence of vas deferens & renal anomalies

    PubMed Central

    Gajbhiye, Rahul; Kadam, Kaushiki; Khole, Aalok; Gaikwad, Avinash; Kadam, Seema; Shah, Rupin; Kumaraswamy, Rangaswamy; Khole, Vrinda

    2016-01-01

    Background & objectives: The role of cystic fibrosis transmembrane conductance regulator (CFTR) gene mutations in congenital bilateral absence of vas deferens and unilateral renal agenesis (CBAVD-URA) has been controversial. Here, we report the cases of five Indian males with CBAVD-URA. The objective was to evaluate the presence or absence of CFTR gene mutations and variants in CBAVD-URA. The female partners of these males were also screened for cystic fibrosis (CF) carrier status. Methods: Direct DNA sequencing of CFTR gene was carried out in five Indian infertile males having CBAVD-URA. Female partners (n=5) and healthy controls (n=32) were also screened. Results: Three potential regulatory CFTR gene variants (c.1540A>G, c.2694T>G and c.4521G>A) were detected along with IVS8-5T mutation in three infertile males with CBAVD-URA. Five novel CFTR gene variants (c.621+91A>G, c.2752+106A>T, c.2751+85_88delTA, c.3120+529InsC and c.4375-69C>T), four potential regulatory CFTR gene variants (M470V, T854T, P1290P, Q1463Q) and seven previously reported CFTR gene variants (c.196+12T>C, c.875+40A>G, c.3041-71G>C, c.3271+42A>T, c.3272-93T>C, c.3500-140A>C and c.3601-65C>A) were detected in infertile men having CBAVD and renal anomalies Interpretation & conclusions: Based on our findings, we speculate that CBAVD-URA may also be attributed to CFTR gene mutations and can be considered as CFTR-related disorder (CFTR-RD). The CFTR gene mutation screening may be offered to CBAVD-URA men and their female partners undergoing ICSI. Further studies need to be done in a large sample to confirm the findings. PMID:27488005

  15. A composite SWNT-collagen matrix: characterization and preliminary assessment as a conductive peripheral nerve regeneration matrix

    NASA Astrophysics Data System (ADS)

    Tosun, Z.; McFetridge, P. S.

    2010-12-01

    Unique in their structure and function, single-walled carbon nanotubes (SWNTs) have received significant attention due to their potential to create unique conductive materials. For neural applications, these conductive materials hold promise as they may enhance regenerative processes. However, like other nano-scaled biomaterials it is important to have a comprehensive understanding how these materials interact with cell systems and how the biological system responds to their presence. These investigations aim to further our understanding of SWNT-cell interactions by assessing the effect SWNT/collagen hydrogels have on PC12 neuronal-like cells seeded within and (independently) on top of the composite material. Two types of collagen hydrogels were prepared: (1) SWNTs dispersed directly within the collagen (SWNT/COL) and (2) albumin-coated SWNTs prepared using the surfactant 'sodium cholate' to improve dispersion (AL-SWNT/COL) and collagen alone serving as a control (COL). SWNT dispersion was significantly improved when using surfactant-assisted dispersion. The enhanced dispersion resulted in a stiffer, more conductive material with an increased collagen fiber diameter. Short-term cell interactions with PC12 cells and SWNT composites have shown a stimulatory effect on cell proliferation relative to plain collagen controls. In parallel to these results, p53 gene displayed normal expression levels, which indicates the absence of nanoparticle-induced DNA damage. In summary, these mechanically tunable SWNT-collagen scaffolds show the potential for enhanced electrical activity and have shown positive in vitro biocompatibility results offering further evidence that SWNT-based materials have an important role in promoting neuronal regeneration.

  16. Effect of high-frequency repetitive transcranial magnetic stimulation on motor cortical excitability and sensory nerve conduction velocity in subacute-stage incomplete spinal cord injury patients.

    PubMed

    Cha, Hyun Gyu; Ji, Sang-Goo; Kim, Myoung-Kwon

    2016-07-01

    [Purpose] The aim of the present study was to determine whether repetitive transcranial magnetic stimulation can improve sensory recovery of the lower extremities in subacute-stage spinal cord injury patients. [Subjects and Methods] This study was conducted on 20 subjects with diagnosed paraplegia due to spinal cord injury. These 20 subjects were allocated to an experimental group of 10 subjects that underwent active repetitive transcranial magnetic stimulation or to a control group of 10 subjects that underwent sham repetitive transcranial magnetic stimulation. The SCI patients in the experimental group underwent active repetitive transcranial magnetic stimulation and conventional rehabilitation therapy, whereas the spinal cord injury patients in the control group underwent sham repetitive transcranial magnetic stimulation and conventional rehabilitation therapy. Participants in both groups received therapy five days per week for six-weeks. Latency, amplitude, and sensory nerve conduction velocity were assessed before and after the six week therapy period. [Results] A significant intergroup difference was observed for posttreatment velocity gains, but no significant intergroup difference was observed for amplitude or latency. [Conclusion] repetitive transcranial magnetic stimulation may be improve sensory recovery of the lower extremities in subacute-stage spinal cord injury patients. PMID:27512251

  17. An association between phantom limb sensations and stump skin conductance during transcutaneous electrical nerve stimulation (TENS) applied to the contralateral leg: a case study.

    PubMed

    Katz, J; France, C; Melzack, R

    1989-03-01

    This report describes a placebo-controlled study of transcutaneous electrical nerve stimulation (TENS) applied to the contralateral lower leg and outer ears of an amputee with non-painful phantom sensations. The subject received TENS or placebo stimulation on separate sessions in which baseline periods of no stimulation alternated with periods of TENS (or placebo). Throughout the two sessions, continuous measures of stump skin conductance, surface skin temperature and phantom intensity were obtained. The results showed that TENS applied to the contralateral leg was significantly more effective than a placebo in decreasing the intensity of phantom sensations, whereas stimulation of the outer ears led to a non-significant increase. The pattern of electrodermal activity on the TENS session was consistently linear during baseline periods, indicating a progressive increase in sympathetic sudomotor activity. In contrast, during periods of electrical stimulation the pattern of electrodermal activity was consistently curvilinear indicating an initial decrease followed by an increase in sudomotor responses. Changes in stump skin conductance correlated significantly with changes in phantom sensations both in TENS and placebo sessions suggesting a relationship between sympathetic activity at the stump and paresthesias referred to the phantom. Two hypotheses are presented to account for these findings. PMID:2785260

  18. Effect of high-frequency repetitive transcranial magnetic stimulation on motor cortical excitability and sensory nerve conduction velocity in subacute-stage incomplete spinal cord injury patients

    PubMed Central

    Cha, Hyun Gyu; Ji, Sang-Goo; Kim, Myoung-Kwon

    2016-01-01

    [Purpose] The aim of the present study was to determine whether repetitive transcranial magnetic stimulation can improve sensory recovery of the lower extremities in subacute-stage spinal cord injury patients. [Subjects and Methods] This study was conducted on 20 subjects with diagnosed paraplegia due to spinal cord injury. These 20 subjects were allocated to an experimental group of 10 subjects that underwent active repetitive transcranial magnetic stimulation or to a control group of 10 subjects that underwent sham repetitive transcranial magnetic stimulation. The SCI patients in the experimental group underwent active repetitive transcranial magnetic stimulation and conventional rehabilitation therapy, whereas the spinal cord injury patients in the control group underwent sham repetitive transcranial magnetic stimulation and conventional rehabilitation therapy. Participants in both groups received therapy five days per week for six-weeks. Latency, amplitude, and sensory nerve conduction velocity were assessed before and after the six week therapy period. [Results] A significant intergroup difference was observed for posttreatment velocity gains, but no significant intergroup difference was observed for amplitude or latency. [Conclusion] repetitive transcranial magnetic stimulation may be improve sensory recovery of the lower extremities in subacute-stage spinal cord injury patients. PMID:27512251

  19. Optic nerve hypoplasia

    PubMed Central

    Kaur, Savleen; Jain, Sparshi; Sodhi, Harsimrat B. S.; Rastogi, Anju; Kamlesh

    2013-01-01

    Optic nerve hypoplasia (ONH) is a congenital anomaly of the optic disc that might result in moderate to severe vision loss in children. With a vast number of cases now being reported, the rarity of ONH is obviously now refuted. The major aspects of ophthalmic evaluation of an infant with possible ONH are visual assessment, fundus examination, and visual electrophysiology. Characteristically, the disc is small, there is a peripapillary double-ring sign, vascular tortuosity, and thinning of the nerve fiber layer. A patient with ONH should be assessed for presence of neurologic, radiologic, and endocrine associations. There may be maternal associations like premature births, fetal alcohol syndrome, maternal diabetes. Systemic associations in the child include endocrine abnormalities, developmental delay, cerebral palsy, and seizures. Besides the hypoplastic optic nerve and chiasm, neuroimaging shows abnormalities in ventricles or white- or gray-matter development, septo-optic dysplasia, hydrocephalus, and corpus callosum abnormalities. There is a greater incidence of clinical neurologic abnormalities in patients with bilateral ONH (65%) than patients with unilateral ONH. We present a review on the available literature on the same to urge caution in our clinical practice when dealing with patients with ONH. Fundus photography, ocular coherence tomography, visual field testing, color vision evaluation, neuroimaging, endocrinology consultation with or without genetic testing are helpful in the diagnosis and management of ONH. (Method of search: MEDLINE, PUBMED). PMID:24082663

  20. Nerve biopsy

    MedlinePlus

    ... Loss of axon tissue Metabolic neuropathies Necrotizing vasculitis Sarcoidosis Risks Allergic reaction to the local anesthetic Discomfort ... Neurosarcoidosis Peripheral neuropathy Primary amyloidosis Radial nerve dysfunction Sarcoidosis Tibial nerve dysfunction Update Date 6/1/2015 ...

  1. Large conductance calcium-activated potassium channels: their expression and modulation of glutamate release from nerve terminals isolated from rat trigeminal caudal nucleus and cerebral cortex.

    PubMed

    Samengo, Irene; Currò, Diego; Barrese, Vincenzo; Taglialatela, Maurizio; Martire, Maria

    2014-05-01

    Large conductance, calcium-activated potassium channels [big potassium (BK) channel] consist of a tetramer of pore-forming α-subunit and distinct accessory β-subunits (β1-4) that modify the channel's properties. In this study, we analyzed the effects of BK channel activators and blockers on glutamate and γ-aminobutyric acid (GABA) release from synaptosomes isolated from the cerebral cortices or trigeminal caudal nuclei (TCN) of rats. Real-time polymerase chain reaction was used to characterize BK channel α and β(1-4) subunit expression in the cortex and in the trigeminal ganglia (TG), whose neurons project primary terminal afferents into the TCN. Immunocytochemistry was used to localize these subunits on cortical and TCN synaptosomes. The BK channels regulating [(3)H]D-aspartate release from primary afferent nerve terminals projecting into the TCN displayed limited sensitivity to iberiotoxin, whereas those expressed on cortical synaptosomes were highly sensitive to this toxin. BK channels did not appear to be present on GABAergic nerve terminals from the TCN since [(3)H]-γ-aminobutyric acid release in this model was unaffected by BK channel activators or blockers. Gene expression studies revealed expression levels of the α subunit in the TG that were only 31.2 ± 2.1% of those found in cortical tissues. The β4 subunit was the accessory subunit expressed most abundantly in both the cortex and TG. Levels of β1 and β2 were low in both these areas although β2 expression in the TG was higher than that found in the cortex. Immunocytochemistry experiments showed that co-localization of α and β4 subunits (the accessory subunit most abundantly expressed in both brain areas) was more common in TCN synaptosomes than in cortical synaptosomes. On the basis of these findings, it is reasonable to hypothesize that BK channels expressed on glutamatergic terminals in the TCN and cortex have distinct pharmacological profiles, which probably reflect different α and

  2. Nerve and muscle involvement in mitochondrial disorders: an electrophysiological study.

    PubMed

    Mancuso, Michelangelo; Piazza, Selina; Volpi, Leda; Orsucci, Daniele; Calsolaro, Valeria; Caldarazzo Ienco, Elena; Carlesi, Cecilia; Rocchi, Anna; Petrozzi, Lucia; Calabrese, Rosanna; Siciliano, Gabriele

    2012-04-01

    Involvement of the peripheral nervous system in mitochondrial disorders (MD) has been previously reported. However, the exact prevalence of peripheral neuropathy and/or myopathy in MD is still unclear. In order to evaluate the prevalence of neuropathy and myopathy in MD, we performed sensory and motor nerve conduction studies (NCS) and concentric needle electromyography (EMG) in 44 unselected MD patients. NCS were abnormal in 36.4% of cases, and were consistent with a sensori-motor axonal multineuropathy (multifocal neuropathy), mainly affecting the lower limbs. EMG evidence of myopathy was present in 54.5% of patients, again mainly affecting the lower limbs. Nerve and muscle involvement was frequently subclinical. Peripheral nerve and muscle involvement is common in MD patients. Our study supports the variability of the clinical expression of MD. Further studies are needed to better understand the molecular basis underlying the phenotypic variability among MD patients. PMID:21751099

  3. On the number and nature of regenerating myelinated axons after lesions of cutaneous nerves in the cat.

    PubMed Central

    Horch, K W; Lisney, S J

    1981-01-01

    1. Electrophysiological and anatomical techniques were used to investigate normal and regenerating sural and posterior femoral cutaneous nerve fibres in the cat. 2. One and a half years after transection of these nerves it was found that the regenerating neurones supported multiple sprouts in the distal stump of the nerve. The branching occurred at or beyond the level of the neuroma and some of the branched fibres innervated split receptive fields on the skin. 3. Counts of the number of axons in the proximal stumps of transected nerves showed that the whole original population of myelinated fibres persisted for at least 18 months. About 75% of these fibres successfully crossed the unrepaired transection site and regenerated into the distal stump of the nerve to re-form functional connexions in the skin. 4. After nerve crush all the myelinated axons regenerated. None showed signs of abnormal branching. 5. After crush the conduction velocities of the regenerated axons in the distal stump of the nerve reached nearly normal values by 6 months. After nerve transection the distal conduction velocities were reduced to 50% of normal even 18 months after the injury. 6. The implications of these findings for the recovery of function after nerve injury in man are discussed. PMID:7277219

  4. The small conductance Ca2+-activated K+ channel SK3 is localized in nerve terminals of excitatory synapses of cultured mouse hippocampal neurons.

    PubMed

    Obermair, Gerald J; Kaufmann, Walter A; Knaus, Hans-Günther; Flucher, Bernhard E

    2003-02-01

    In the central nervous system small conductance Ca2+-activated K+ (SK) channels are important for generating the medium/slow afterhyperpolarization seen after single or trains of action potentials. Three SK channel isoforms (SK1,-2,-3) are differentially distributed throughout the brain, but little is known about their specific expression in particular neuronal compartments. In the hippocampus SK3 was found in the neuropil, predominantly in the terminal field of the mossy fibres and in fine varicose fibres, but excluded from the pyramidal and granule cell layers. Because this expression pattern suggested a presynaptic localization, we examined the subcellular distribution of SK3 in cultured hippocampal neurons using high-resolution immunofluorescence analysis. SK3 was localized in a punctate, synaptic pattern. The SK3 clusters were precisely colocalized with the presynaptic marker synapsin and at close range (0.4-0.5 microm) from NMDA-receptors and PSD-95. This arrangement is consistent with a localization of SK3 in the presynaptic nerve terminal, but not restricted to the synaptic membrane proper. In agreement with the increasing expression of SK3 during early postnatal development in vivo, the fraction of synapses containing SK3 increased from 14% to 57% over a six-week culture period. SK3-containing synapses were equally observed on spiny, glutamatergic and smooth GABAergic neurons. In contrast to its close association with NMDA-receptors and PSD-95, SK3 was rarely associated with GABAA-receptor clusters. Thus, SK3 is a presynaptic channel in excitatory hippocampal synapses, with no preference for glutamatergic or GABAergic postsynaptic neurons, and is probably involved in regulating neurotransmitter release.

  5. Acrylamide inhibits nerve sprouting induced by botulinum toxin type A

    PubMed Central

    Jiang, Hong; Xiang, Yi; Hu, Xingyue; Cai, Huaying

    2014-01-01

    Botulinum toxin type A is a potent muscle relaxant that blocks the transmission and release of acetylcholine at the neuromuscular junction. Intramuscular injection of botulinum toxin type A has served as an effective and safe therapy for strabismus and focal dystonia. However, muscular weakness is temporary and after 3–4 months, muscle strength usually recovers because functional recovery is mediated by nerve sprouting and reconstruction of the neuromuscular junction. Acrylamide may produce neurotoxic substances that cause retrograde necrotizing neuropathy and inhibit nerve sprouting caused by botulinum toxin type A. This study investigated whether acrylamide inhibits nerve sprouting after intramuscular injection of botulinum toxin type A. A tibial nerve sprouting model was established through local injection of botulinum toxin type A into the right gastrocnemius muscle of Sprague-Dawley rats. Following intramuscular injection, rats were given intraperitoneal injection of 3% acrylamide every 3 days for 21 days. Nerve sprouting appeared 2 weeks after intramuscular injection of botulinum toxin type A and single-fiber electromyography revealed abnormal conduction at the neuromuscular junction 1 week after intramuscular injection of botulinum toxin type A. Following intraperitoneal injection of acrylamide, the peak muscle fiber density decreased. Electromyography jitter value were restored to normal levels 6 weeks after injection. This indicates that the maximal decrease in fiber density and the time at which functional conduction of neuromuscular junction was restored were delayed. Additionally, the increase in tibial nerve fibers was reduced. Acrylamide inhibits nerve sprouting caused by botulinum toxin type A and may be used to prolong the clinical dosage of botulinum toxin type A. PMID:25317170

  6. Transcranial magnetic stimulation studies in the Miller Fisher syndrome: evidence of corticospinal tract abnormality

    PubMed Central

    Lo, Y; Ratnagopal, P

    2001-01-01

    OBJECTIVES—To evaluate serial central motor conduction time in the Miller Fisher syndrome.
METHOD—Three patients with classic Miller Fisher syndrome were evaluated clinically. They had serial central motor conduction times measured with transcranial magnetic stimulation and nerve conduction studies. Motor evoked potentials were recorded from the first dorsal interossei and abductor hallucis muscles.
RESULTS—All three patients showed reduction in central motor conduction times in tandem with gradual clinical improvement at each review.
CONCLUSIONS—There is electrophysiological evidence of a central reversible corticospinal tract conduction abnormality in the Miller Fisher syndrome.

 PMID:11459894

  7. Meiotic abnormalities

    SciTech Connect

    1993-12-31

    Chapter 19, describes meiotic abnormalities. These include nondisjunction of autosomes and sex chromosomes, genetic and environmental causes of nondisjunction, misdivision of the centromere, chromosomally abnormal human sperm, male infertility, parental age, and origin of diploid gametes. 57 refs., 2 figs., 1 tab.

  8. Aminoguanidine effects on nerve blood flow, vascular permeability, electrophysiology, and oxygen free radicals.

    PubMed Central

    Kihara, M; Schmelzer, J D; Poduslo, J F; Curran, G L; Nickander, K K; Low, P A

    1991-01-01

    Since advanced glycosylation end products have been suggested to mediate hyperglycemia-induced microvascular atherogenesis and because aminoguanidine (AG) prevents their generation, we examined whether AG could prevent or ameliorate the physiologic and biochemical indices of streptozotocin (STZ)-induced experimental diabetic neuropathy. Four groups of adult Sprague-Dawley rats were studied: group I received STZ plus AG (25 mg.kg-1.day-1), group II received STZ plus AG (50 mg.kg-1.day-1), group III received STZ alone, and group IV was a control. We monitored conduction and action potential amplitudes serially in sciatic-tibial and caudal nerves, nerve blood flow, oxygen free radical activity (conjugated dienes and hydroperoxides), and the product of the permeability coefficient and surface area to 125I-labeled albumin. STZ-induced diabetes (group III) caused a 57% reduction in nerve blood flow and in abnormal nerve conduction and amplitudes and a 60% increase in conjugated dienes. Nerve blood flow was normalized by 8 weeks with AG (groups I and II) and conduction was significantly improved, in a dose-dependent manner, by 16 and 24 weeks in sciatic-tibial and caudal nerves, respectively. The permeability coefficient was not impaired, suggesting a normal blood-nerve barrier function for albumin, and the oxygen free-radical indices were not ameliorated by AG. We suggest that AG reverses nerve ischemia and more gradually improves their electrophysiology by an action on nerve microvessels. AG may have potential in the treatment of diabetic neuropathy. PMID:2068089

  9. Craniofacial Abnormalities

    MedlinePlus

    ... of the skull and face. Craniofacial abnormalities are birth defects of the face or head. Some, like cleft ... palate, are among the most common of all birth defects. Others are very rare. Most of them affect ...

  10. Chromosome Abnormalities

    MedlinePlus

    ... decade, newer techniques have been developed that allow scientists and doctors to screen for chromosomal abnormalities without using a microscope. These newer methods compare the patient's DNA to a normal DNA ...

  11. Walking abnormalities

    MedlinePlus

    ... include: Arthritis of the leg or foot joints Conversion disorder (a psychological disorder) Foot problems (such as a ... injuries. For an abnormal gait that occurs with conversion disorder, counseling and support from family members are strongly ...

  12. Nail abnormalities

    MedlinePlus

    Beau's lines; Fingernail abnormalities; Spoon nails; Onycholysis; Leukonychia; Koilonychia; Brittle nails ... Just like the skin, the fingernails tell a lot about your health: ... the fingernail. These lines can occur after illness, injury to ...

  13. Ephaptic coupling of myelinated nerve fibers

    NASA Astrophysics Data System (ADS)

    Binczak, S.; Eilbeck, J. C.; Scott, A. C.

    2001-01-01

    Numerical predictions of a simple myelinated nerve fiber model are compared with theoretical results in the continuum and discrete limits, clarifying the nature of the conduction process on an isolated nerve axon. Since myelinated nerve fibers are often arranged in bundles, this model is used to study ephaptic (nonsynaptic) interactions between impulses on parallel fibers, which may play a functional role in neural processing.

  14. Electrophysiological evaluation of nerve function in inferior alveolar nerve injury: relationship between nerve action potentials and histomorphometric observations.

    PubMed

    Murayama, M; Sasaki, K; Shibahara, T

    2015-12-01

    The objective of this study was to improve the accuracy of diagnosis of inferior alveolar nerve (IAN) injury by determining degrees of nerve disturbance using the sensory nerve action potential (SNAP) and sensory nerve conduction velocity (SCV). Crush and partial and complete nerve amputation injuries were applied to the IAN of rabbits, then SNAPs and histomorphometric observations were recorded at 1, 5, and 10 weeks. For crush injury, most nerves were smaller in diameter at 5 weeks than at 1 week, however after 10 weeks, extensive nerve regeneration was observed. The SNAP showed a decrease in SCV at weeks 1 and 5, followed by an increase at week 10. For partial nerve amputation, small to medium-sized nerve fibres were observed at weeks 1 and 5, then larger nerves were seen at week 10. Minimal changes in SCV were observed at weeks 1 and 5, however SCV increased at week 10. For complete nerve amputation, nerve fibres were sparse at week 1, but gradual nerve regeneration was observed at weeks 5 and 10. SNAPs were detectable from week 10, however the SCV was extremely low. This study showed SCV to be an effective factor in the evaluation of nerve injury and regeneration. PMID:26433750

  15. Ion Channels in Nerve Membranes

    ERIC Educational Resources Information Center

    Ehrenstein, Gerald

    1976-01-01

    Discusses research that indicates that nerve membranes, which play a key role in the conduction of impulses, are traversed by protein channels with ion pathways opened and closed by the membrane electric field. (Author/MLH)

  16. Radiation-induced malignant and atypical peripheral nerve sheath tumors

    SciTech Connect

    Foley, K.M.; Woodruff, J.M.; Ellis, F.T.; Posner, J.B.

    1980-04-01

    The reported peripheral nerve complications of therapeutic irradiation in humans include brachial and lumbar plexus fibrosis and cranial and peripheral nerve atrophy. We have encountered 9 patients with malignant (7) and atypical (2) peripheral nerve tumors occurring in an irradiated site suggesting that such tumors represent another delayed effect of radiation treatment on peripheral nerve. In all instances the radio-theray was within an acceptable radiation dosage, yet 3 patients developed local radiation-induced skin and bony abnormalities. The malignant peripheral nerve sheath tumors developed only in the radiation port. Animal studies support the clinical observation that malignant peripheral nerve sheath tumors can occur as a delayed effect of irradiation.

  17. Changes in nerve function and nerve fibre structure induced by acute, graded compression.

    PubMed Central

    Rydevik, B; Nordborg, C

    1980-01-01

    Rabbit tibial nerves were subjected to direct, acute graded compression by means of an inflatable compression chamber. The acute and long term effects of 50, 200 and 400 mmHg applied for two hours on nerve function and nerve fibre structure were investigated. A pressure of 50 mmHg applied for two hours induced only minimal or no acute deterioration of maximal conduction velocity and nerve fibre structure. Conduction velocity was gradually reduced during compression at 200-400 mmHg pressure for two hours and in those cases the recovery of nerve conduction after pressure release was incomplete. Ultrastructural analysis revealed pronounced, early nerve fibre damage in these nerves. Three weeks after compression, nerves compressed at 50 mmHg for two hours had normal afferent and motor conduction velocity, although there were morphological signs of slight nerve fibre damage. Nerves compressed at 200 mmHg for two hours exhibited reduction of conduction velocity only at the level of compression, in contrast to the nerves compressed at 400 mmHg for two hours in which conduction velocity was reduced both at the level of compression and distal to the compressed segment. Morphologically, the nerves compressed at 200-400 mmHg for two hours showed varying degrees of demyelination and axonal degeneration three weeks after compression. Images PMID:7217952

  18. Imaging the Facial Nerve: A Contemporary Review

    PubMed Central

    Gupta, Sachin; Mends, Francine; Hagiwara, Mari; Fatterpekar, Girish; Roehm, Pamela C.

    2013-01-01

    Imaging plays a critical role in the evaluation of a number of facial nerve disorders. The facial nerve has a complex anatomical course; thus, a thorough understanding of the course of the facial nerve is essential to localize the sites of pathology. Facial nerve dysfunction can occur from a variety of causes, which can often be identified on imaging. Computed tomography and magnetic resonance imaging are helpful for identifying bony facial canal and soft tissue abnormalities, respectively. Ultrasound of the facial nerve has been used to predict functional outcomes in patients with Bell's palsy. More recently, diffusion tensor tractography has appeared as a new modality which allows three-dimensional display of facial nerve fibers. PMID:23766904

  19. Neural autoantibodies and neurophysiologic abnormalities in patients exposed to molds in water-damaged buildings.

    PubMed

    Campbell, Andrew W; Thrasher, Jack D; Madison, Roberta A; Vojdani, Aristo; Gray, Michael R; Johnson, Al

    2003-08-01

    Adverse health effects of fungal bioaerosols on occupants of water-damaged homes and other buildings have been reported. Recently, it has been suggested that mold exposure causes neurological injury. The authors investigated neurological antibodies and neurophysiological abnormalities in patients exposed to molds at home who developed symptoms of peripheral neuropathy (i.e., numbness, tingling, tremors, and muscle weakness in the extremities). Serum samples were collected and analyzed with the enzyme-linked immunosorbent assay (ELISA) technique for antibodies to myelin basic protein, myelin-associated glycoprotein, ganglioside GM1, sulfatide, myelin oligodendrocyte glycoprotein, alpha-B-crystallin, chondroitin sulfate, tubulin, and neurofilament. Antibodies to molds and mycotoxins were also determined with ELISA, as reported previously. Neurophysiologic evaluations for latency, amplitude, and velocity were performed on 4 motor nerves (median, ulnar, peroneal, and tibial), and for latency and amplitude on 3 sensory nerves (median, ulnar, and sural). Patients with documented, measured exposure to molds had elevated titers of antibodies (immunoglobulin [Ig]A, IgM, and IgG) to neural-specific antigens. Nerve conduction studies revealed 4 patient groupings: (1) mixed sensory-motor polyneuropathy (n = 55, abnormal), (2) motor neuropathy (n = 17, abnormal), (3) sensory neuropathy (n = 27, abnormal), and (4) those with symptoms but no neurophysiological abnormalities (n = 20, normal controls). All groups showed significantly increased autoantibody titers for all isotypes (IgA, IgM, and IgG) of antibodies to neural antigens when compared with 500 healthy controls. Groups 1 through 3 also exhibited abnormal neurophysiologic findings. The authors concluded that exposure to molds in water-damaged buildings increased the risk for development of neural autoantibodies, peripheral neuropathy, and neurophysiologic abnormalities in exposed individuals. PMID:15259425

  20. Multifocal motor neuropathy: pathologic alterations at the site of conduction block.

    PubMed

    Taylor, Bruce V; Dyck, P James B; Engelstad, JaNean; Gruener, Gregory; Grant, Ian; Dyck, Peter J

    2004-02-01

    The pathologic changes of nerves in multifocal motor neuropathy (MMN), a rare neuropathy with selective focal conduction block of motor fibers in mixed nerves, remain essentially unstudied. Fascicular nerve biopsy of 8 forearm or arm nerves in 7 patients with typical MMN was undertaken for diagnostic reasons at the site of the conduction block. Abnormalities were seen in 7 of 8 nerves, including a varying degree of multifocal fiber degeneration and loss, an altered fiber size distribution with fewer large fibers, an increased frequency of remyelinated fiber profiles, and frequent and prominent regenerating fiber clusters. Small epineurial perivascular inflammatory infiltrates were observed in 2 nerves. We did not observe overt segmental demyelination or onion bulb formation. We hypothesize that an antibody-mediated attack directed against components of axolemma at nodes of Ranvier could cause conduction block, transitory paranodal demyelination and remyelination, and axonal degeneration and regeneration. Alternatively, the antibody attack could be directed at components of paranodal myelin. We favor the first hypothesis because in nerves studied by us, axonal pathological alteration predominated over myelin pathology. Irrespective of which mechanism is involved, we conclude that the unequivocal multifocal fiber degeneration and loss and regenerative clusters at sites of conduction block explains the observed clinical muscle weakness and atrophy and alterations of motor unit potentials. The occurrence of conduction block and multifocal fiber degeneration and regeneration at the same sites suggests that the processes of conduction block and fiber degeneration and regeneration are linked. Finding discrete multifocal fiber degeneration may also provide an explanation for why the functional abnormalities remain unchanged over long periods of time at discrete proximal to distal levels of nerve and may emphasize a need for early intervention (assuming that efficacious

  1. Peripheral nerve hyperexcitability syndromes.

    PubMed

    Küçükali, Cem Ismail; Kürtüncü, Murat; Akçay, Halil İbrahim; Tüzün, Erdem; Öge, Ali Emre

    2015-01-01

    Peripheral nerve hyperexcitability (PNH) syndromes can be subclassified as primary and secondary. The main primary PNH syndromes are neuromyotonia, cramp-fasciculation syndrome (CFS), and Morvan's syndrome, which cause widespread symptoms and signs without the association of an evident peripheral nerve disease. Their major symptoms are muscle twitching and stiffness, which differ only in severity between neuromyotonia and CFS. Cramps, pseudomyotonia, hyperhidrosis, and some other autonomic abnormalities, as well as mild positive sensory phenomena, can be seen in several patients. Symptoms reflecting the involvement of the central nervous system occur in Morvan's syndrome. Secondary PNH syndromes are generally seen in patients with focal or diffuse diseases affecting the peripheral nervous system. The PNH-related symptoms and signs are generally found incidentally during clinical or electrodiagnostic examinations. The electrophysiological findings that are very useful in the diagnosis of PNH are myokymic and neuromyotonic discharges in needle electromyography along with some additional indicators of increased nerve fiber excitability. Based on clinicopathological and etiological associations, PNH syndromes can also be classified as immune mediated, genetic, and those caused by other miscellaneous factors. There has been an increasing awareness on the role of voltage-gated potassium channel complex autoimmunity in primary PNH pathogenesis. Then again, a long list of toxic compounds and genetic factors has also been implicated in development of PNH. The management of primary PNH syndromes comprises symptomatic treatment with anticonvulsant drugs, immune modulation if necessary, and treatment of possible associated dysimmune and/or malignant conditions. PMID:25719304

  2. Peripheral Nerve Disorders

    MedlinePlus

    ... spinal cord. Like static on a telephone line, peripheral nerve disorders distort or interrupt the messages between the brain ... body. There are more than 100 kinds of peripheral nerve disorders. They can affect one nerve or many nerves. ...

  3. Nerve biopsy (image)

    MedlinePlus

    Nerve biopsy is the removal of a small piece of nerve for examination. Through a small incision, a sample ... is removed and examined under a microscope. Nerve biopsy may be performed to identify nerve degeneration, identify ...

  4. Nerve injuries due to obstetric trauma.

    PubMed

    Bhat, V; Ravikumara; Oumachigui, A

    1995-01-01

    The incidence of nerve injuries among 32,637 deliveries over a period of ten years was 1.81/1000. Brachial plexus injury (1/1000) and facial nerve injury (0.74/1000) accounted for 98% of nerve injuries. Both the right and left side were involved equally. Bilateral nerve injury was not seen. Lack of antenatal care, macrosomia, abnormal presentations, and operative vaginal deliveries significantly increased the risk of nerve injuries. These babies had significantly higher incidence of meconium stained liquor and intrapartum asphyxia. Parity of the mother, gestational age and sex of the baby did not have significant role in the causation of nerve injuries. Injuries to brachial plexus and facial nerve were seen even in babies born by caesarean section, when it was performed for obstructed labour caused by cephalo-pelvic disproportion and abnormal presentations. Three babies with injuries expired and forty-three could be followed up for varying periods. None of the babies had residual defects. Detection of cephalopelvic disproportion and abnormal lie in the third trimester and their appropriate management would decrease the incidence of obstetric palsies to a significant extent. PMID:10829869

  5. Application of implantable wireless biomicrosystem for monitoring nerve impedance of rat after sciatic nerve injury.

    PubMed

    Li, Yu-Ting; Peng, Chih-Wei; Chen, Lung-Tai; Lin, Wen-Shan; Chu, Chun-Hsun; Chen, Jia-Jin Jason

    2013-01-01

    Electrical stimulation is usually applied percutaneously for facilitating peripheral nerve regeneration. However, few studies have conducted long-term monitoring of the condition of nerve regeneration. This study implements an implantable biomicrosystem for inducing pulse current for aiding nerve repair and monitoring the time-course changes of nerve impedance for assessing nerve regeneration in sciatic nerve injury rat model. For long-term implantation, a transcutaneous magnetic coupling technique is adopted for power and data transmission. For in vivo study, the implanted module was placed in the rat's abdomen and the cuff electrode was wrapped around an 8-mm sciatic nerve gap of the rat for nerve impedance measurement for 42 days. One group of animals received monophasic constant current via the cuff electrode and a second group had no stimulation between days 8-21. The nerve impedance increased to above 150% of the initial value in the nerve regeneration groups with and without stimulation whereas the group with no nerve regeneration increased to only 113% at day 42. The impedance increase in nerve regeneration groups can be observed before evident functional recovery. Also, the nerve regeneration group that received electrical stimulation had relatively higher myelinated fiber density than that of no stimulation group, 20686 versus 11417 fiber/mm (2). The developed implantable biomicrosystem is proven to be a useful experimental tool for long-term stimulation in aiding nerve fiber growth as well as impedance assessment for understanding the time-course changes of nerve regeneration. PMID:23060343

  6. Congenital optic nerve anomalies and hereditary optic neuropathies

    PubMed Central

    Heidary, Gena

    2014-01-01

    Congenital and hereditary optic nerve anomalies represent a significant cause of visual dysfunction. While some optic nerve abnormalities affect the visual system alone, others may be associated with neurologic and systemic findings. Correct identification of the optic nerve disease therefore is crucial both for developing a treatment plan with respect to visual rehabilitation, but also for initiating the appropriate multidisciplinary evaluation. The purpose of this review is to highlight common examples of congenital and inherited optic nerve abnormalities in an effort to familiarize the clinician with salient clinical features of these diseases and to review important systemic testing when relevant. PMID:27625883

  7. Restoration of auditory nerve synapses in cats by cochlear implants.

    PubMed

    Ryugo, D K; Kretzmer, E A; Niparko, J K

    2005-12-01

    Congenital deafness results in abnormal synaptic structure in endings of the auditory nerve. If these abnormalities persist after restoration of auditory nerve activity by a cochlear implant, the processing of time-varying signals such as speech would likely be impaired. We stimulated congenitally deaf cats for 3 months with a six-channel cochlear implant. The device used human speech-processing programs, and cats responded to environmental sounds. Auditory nerve fibers exhibited a recovery of normal synaptic structure in these cats. This rescue of synapses is attributed to a return of spike activity in the auditory nerve and may help explain cochlear implant benefits in childhood deafness. PMID:16322457

  8. Congenital optic nerve anomalies and hereditary optic neuropathies.

    PubMed

    Heidary, Gena

    2014-12-01

    Congenital and hereditary optic nerve anomalies represent a significant cause of visual dysfunction. While some optic nerve abnormalities affect the visual system alone, others may be associated with neurologic and systemic findings. Correct identification of the optic nerve disease therefore is crucial both for developing a treatment plan with respect to visual rehabilitation, but also for initiating the appropriate multidisciplinary evaluation. The purpose of this review is to highlight common examples of congenital and inherited optic nerve abnormalities in an effort to familiarize the clinician with salient clinical features of these diseases and to review important systemic testing when relevant. PMID:27625883

  9. Tuning PAK Activity to Rescue Abnormal Myelin Permeability in HNPP.

    PubMed

    Hu, Bo; Arpag, Sezgi; Zhang, Xuebao; Möbius, Wiebke; Werner, Hauke; Sosinsky, Gina; Ellisman, Mark; Zhang, Yang; Hamilton, Audra; Chernoff, Jonathan; Li, Jun

    2016-09-01

    Schwann cells in the peripheral nervous systems extend their membranes to wrap axons concentrically and form the insulating sheath, called myelin. The spaces between layers of myelin are sealed by myelin junctions. This tight insulation enables rapid conduction of electric impulses (action potentials) through axons. Demyelination (stripping off the insulating sheath) has been widely regarded as one of the most important mechanisms altering the action potential propagation in many neurological diseases. However, the effective nerve conduction is also thought to require a proper myelin seal through myelin junctions such as tight junctions and adherens junctions. In the present study, we have demonstrated the disruption of myelin junctions in a mouse model (Pmp22+/-) of hereditary neuropathy with liability to pressure palsies (HNPP) with heterozygous deletion of Pmp22 gene. We observed a robust increase of F-actin in Pmp22+/- nerve regions where myelin junctions were disrupted, leading to increased myelin permeability. These abnormalities were present long before segmental demyelination at the late phase of Pmp22+/- mice. Moreover, the increase of F-actin levels correlated with an enhanced activity of p21-activated kinase (PAK1), a molecule known to regulate actin polymerization. Pharmacological inhibition of PAK normalized levels of F-actin, and completely prevented the progression of the myelin junction disruption and nerve conduction failure in Pmp22+/- mice. Our findings explain how abnormal myelin permeability is caused in HNPP, leading to impaired action potential propagation in the absence of demyelination. We call it "functional demyelination", a novel mechanism upstream to the actual stripping of myelin that is relevant to many demyelinating diseases. This observation also provides a potential therapeutic approach for HNPP.

  10. Tuning PAK Activity to Rescue Abnormal Myelin Permeability in HNPP

    PubMed Central

    Hu, Bo; Zhang, Xuebao; Möbius, Wiebke; Werner, Hauke; Sosinsky, Gina; Ellisman, Mark; Zhang, Yang; Hamilton, Audra; Chernoff, Jonathan; Li, Jun

    2016-01-01

    Schwann cells in the peripheral nervous systems extend their membranes to wrap axons concentrically and form the insulating sheath, called myelin. The spaces between layers of myelin are sealed by myelin junctions. This tight insulation enables rapid conduction of electric impulses (action potentials) through axons. Demyelination (stripping off the insulating sheath) has been widely regarded as one of the most important mechanisms altering the action potential propagation in many neurological diseases. However, the effective nerve conduction is also thought to require a proper myelin seal through myelin junctions such as tight junctions and adherens junctions. In the present study, we have demonstrated the disruption of myelin junctions in a mouse model (Pmp22+/-) of hereditary neuropathy with liability to pressure palsies (HNPP) with heterozygous deletion of Pmp22 gene. We observed a robust increase of F-actin in Pmp22+/- nerve regions where myelin junctions were disrupted, leading to increased myelin permeability. These abnormalities were present long before segmental demyelination at the late phase of Pmp22+/- mice. Moreover, the increase of F-actin levels correlated with an enhanced activity of p21-activated kinase (PAK1), a molecule known to regulate actin polymerization. Pharmacological inhibition of PAK normalized levels of F-actin, and completely prevented the progression of the myelin junction disruption and nerve conduction failure in Pmp22+/- mice. Our findings explain how abnormal myelin permeability is caused in HNPP, leading to impaired action potential propagation in the absence of demyelination. We call it “functional demyelination”, a novel mechanism upstream to the actual stripping of myelin that is relevant to many demyelinating diseases. This observation also provides a potential therapeutic approach for HNPP. PMID:27583434

  11. Tuning PAK Activity to Rescue Abnormal Myelin Permeability in HNPP.

    PubMed

    Hu, Bo; Arpag, Sezgi; Zhang, Xuebao; Möbius, Wiebke; Werner, Hauke; Sosinsky, Gina; Ellisman, Mark; Zhang, Yang; Hamilton, Audra; Chernoff, Jonathan; Li, Jun

    2016-09-01

    Schwann cells in the peripheral nervous systems extend their membranes to wrap axons concentrically and form the insulating sheath, called myelin. The spaces between layers of myelin are sealed by myelin junctions. This tight insulation enables rapid conduction of electric impulses (action potentials) through axons. Demyelination (stripping off the insulating sheath) has been widely regarded as one of the most important mechanisms altering the action potential propagation in many neurological diseases. However, the effective nerve conduction is also thought to require a proper myelin seal through myelin junctions such as tight junctions and adherens junctions. In the present study, we have demonstrated the disruption of myelin junctions in a mouse model (Pmp22+/-) of hereditary neuropathy with liability to pressure palsies (HNPP) with heterozygous deletion of Pmp22 gene. We observed a robust increase of F-actin in Pmp22+/- nerve regions where myelin junctions were disrupted, leading to increased myelin permeability. These abnormalities were present long before segmental demyelination at the late phase of Pmp22+/- mice. Moreover, the increase of F-actin levels correlated with an enhanced activity of p21-activated kinase (PAK1), a molecule known to regulate actin polymerization. Pharmacological inhibition of PAK normalized levels of F-actin, and completely prevented the progression of the myelin junction disruption and nerve conduction failure in Pmp22+/- mice. Our findings explain how abnormal myelin permeability is caused in HNPP, leading to impaired action potential propagation in the absence of demyelination. We call it "functional demyelination", a novel mechanism upstream to the actual stripping of myelin that is relevant to many demyelinating diseases. This observation also provides a potential therapeutic approach for HNPP. PMID:27583434

  12. The longitudinal epineural incision and complete nerve transection method for modeling sciatic nerve injury

    PubMed Central

    Cheng, Xing-long; Wang, Pei; Sun, Bo; Liu, Shi-bo; Gao, Yun-feng; He, Xin-ze; Yu, Chang-yu

    2015-01-01

    Injury severity, operative technique and nerve regeneration are important factors to consider when constructing a model of peripheral nerve injury. Here, we present a novel peripheral nerve injury model and compare it with the complete sciatic nerve transection method. In the experimental group, under a microscope, a 3-mm longitudinal incision was made in the epineurium of the sciatic nerve to reveal the nerve fibers, which were then transected. The small, longitudinal incision in the epineurium was then sutured closed, requiring no stump anastomosis. In the control group, the sciatic nerve was completely transected, and the epineurium was repaired by anastomosis. At 2 and 4 weeks after surgery, Wallerian degeneration was observed in both groups. In the experimental group, at 8 and 12 weeks after surgery, distinct medullary nerve fibers and axons were observed in the injured sciatic nerve. Regular, dense myelin sheaths were visible, as well as some scarring. By 12 weeks, the myelin sheaths were normal and intact, and a tight lamellar structure was observed. Functionally, limb movement and nerve conduction recovered in the injured region between 4 and 12 weeks. The present results demonstrate that longitudinal epineural incision with nerve transection can stably replicate a model of Sunderland grade IV peripheral nerve injury. Compared with the complete sciatic nerve transection model, our method reduced the difficulties of micromanipulation and surgery time, and resulted in good stump restoration, nerve regeneration, and functional recovery. PMID:26692866

  13. Early detection of nerve fiber loss by corneal confocal microscopy and skin biopsy in recently diagnosed type 2 diabetes.

    PubMed

    Ziegler, Dan; Papanas, Nikolaos; Zhivov, Andrey; Allgeier, Stephan; Winter, Karsten; Ziegler, Iris; Brüggemann, Jutta; Strom, Alexander; Peschel, Sabine; Köhler, Bernd; Stachs, Oliver; Guthoff, Rudolf F; Roden, Michael

    2014-07-01

    We sought to determine whether early nerve damage may be detected by corneal confocal microscopy (CCM), skin biopsy, and neurophysiological tests in 86 recently diagnosed type 2 diabetic patients compared with 48 control subjects. CCM analysis using novel algorithms to reconstruct nerve fiber images was performed for all fibers and major nerve fibers (MNF) only. Intraepidermal nerve fiber density (IENFD) was assessed in skin specimens. Neurophysiological measures included nerve conduction studies (NCS), quantitative sensory testing (QST), and cardiovascular autonomic function tests (AFTs). Compared with control subjects, diabetic patients exhibited significantly reduced corneal nerve fiber length (CNFL-MNF), fiber density (CNFD-MNF), branch density (CNBD-MNF), connecting points (CNCP), IENFD, NCS, QST, and AFTs. CNFD-MNF and IENFD were reduced below the 2.5th percentile in 21% and 14% of the diabetic patients, respectively. However, the vast majority of patients with abnormal CNFD showed concomitantly normal IENFD and vice versa. In conclusion, CCM and skin biopsy both detect nerve fiber loss in recently diagnosed type 2 diabetes, but largely in different patients, suggesting a patchy manifestation pattern of small fiber neuropathy. Concomitant NCS impairment points to an early parallel involvement of small and large fibers, but the precise temporal sequence should be clarified in prospective studies. PMID:24574045

  14. Abnormal thermal conductivity in tetragonal tungsten bronze Ba{sub 6−x}Sr{sub x}Nb{sub 10}O{sub 30}

    SciTech Connect

    Kolodiazhnyi, T. Sakurai, H.; Vasylkiv, O.; Borodianska, H.; Mozharivskyj, Y.

    2014-03-17

    Ba{sub 6−x}Sr{sub x}Nb{sub 10}O{sub 30} solid solution with 0 ≤ x ≤ 6 crystallizes in centrosymmetric tetragonal “tungsten bronze” structure (space group P4/mbm). We report on the x dependence of thermal conductivity of polycrystalline samples measured in the 2–400 K temperature interval. Substitution of Sr for Ba brings about a significant decrease in thermal conductivity at x ≥ 3 accompanied by development of a low-temperature (T ≈ 10–30 K) “plateau” region reminiscent of a glass-like compounds. We explain this behaviour based on a size-driven site occupancy and atomic displacement parameters associated with an alkaline earth atomic positions in the title compounds.

  15. Promotion of peripheral nerve regeneration and prevention of neuroma formation by PRGD/PDLLA/β-TCP conduit: report of two cases.

    PubMed

    Yin, Yixia; Li, Binbin; Yan, Qiongjiao; Dai, Honglian; Wang, Xinyu; Huang, Jifeng; Li, Shipu

    2015-06-01

    In the field of nerve repair, one major challenge is the formation of neuroma. However, reports on both the promotion of nerve regeneration and prevention of traumatic neuroma in the clinical settings are rare in the field of nerve repair. One of the reasons could be the insufficiency in the follow-up system. We have conducted 33 cases of nerve repair using PRGD/PDLLA/β-TCP conduit without any sign of adverse reaction, especially no neuroma formation. Among them, we have selected two cases as representatives to report in this article. The first case was a patient with an upper limb nerve wound was bridged by PRGD/PDLLA/β-TCP conduit and a plate fixation was given. After nearly 3-years' follow-up, the examination results demonstrated that nerve regeneration effect was very good. When the reoperation was performed to remove the steel plate we observed a uniform structure of the regenerated nerve without the formation of neuroma, and to our delight, the implanted conduit was completely degraded 23 months after the implantation. The second case had an obsolete nerve injury with neuroma formation. After removal of the neuroma, the nerve was bridged by PRGD/PDLLA/β-TCP conduit. Follow-up examinations showed that the structure and functional recovery were improved gradually in the 10-month follow-up; no end-enlargement and any other abnormal reaction associated with the characteristic of neuroma were found. Based on our 33-case studies, we have concluded that PRGD/PDLLA/β-TCP nerve conduit could both promote nerve regeneration and prevent neuroma formation; therefore, it is a good alternative for peripheral nerve repair. PMID:26816636

  16. The Six Syndromes of the Sixth Cranial Nerve

    PubMed Central

    Azarmina, Mohsen; Azarmina, Hossein

    2013-01-01

    The sixth cranial nerve runs a long course from the brainstem to the lateral rectus muscle. Based on the location of an abnormality, other neurologic structures may be involved with the pathology related to this nerve. Sixth nerve palsy is frequently due to a benign process with full recovery within weeks, yet caution is warranted as it may portend a serious neurologic process. Hence, early diagnosis is often critical for some conditions that present with sixth nerve palsy. This article outlines a simple clinical approach to sixth nerve palsy based on its anatomy. PMID:23943691

  17. [The nerve agent sarin: history, clinical manifestations, and treatment].

    PubMed

    Yanagisawa, Nobuo

    2014-05-01

    Organic phosphate pesticides were used worldwide after World War II and experiences on poisoning and treatment have been accumulated. An organic phosphate "nerve agent" Sarin was used in two terrorist attacks in Japan in the 1990s. Sarin effects on humans were well documented in these two incidents. Sarin gas inhalation caused instantaneous death by respiratory arrest in several victims in Matsumoto. Severely injured victims presenting with coma and generalized convulsion were resuscitated and recovered rapidly without sequelae. Miosis and blurred-dark vision, ocular pain, copious secretions from respiratory and gastrointestinal tract (muscarinic effects), and headache were common in severely to slightly affected victims. Plasma cholinesterase (ChE) activity decreased in parallel with the severity of signs and symptoms in victims. Oximes, atropine sulphate, diazepam, and ample intravenous infusion were effective treatments. Follow-up examinations on victims were conducted up to 10 years in Matsumoto, and 5 years in Tokyo. No neurological sequelae or abnormalities were observed after 1 year, except for a few EEG abnormalities or delay in sensory nerve conduction velocity. Posttraumatic stress disorder (PTSD) was observed in several of the victims in the 5-year follow up, irrespective of the severity of poisoning at Matsumoto. Psychological symptoms continue in victims of both incidents.

  18. Transgenic mice with cardiac-specific expression of activating transcription factor 3, a stress-inducible gene, have conduction abnormalities and contractile dysfunction.

    PubMed

    Okamoto, Y; Chaves, A; Chen, J; Kelley, R; Jones, K; Weed, H G; Gardner, K L; Gangi, L; Yamaguchi, M; Klomkleaw, W; Nakayama, T; Hamlin, R L; Carnes, C; Altschuld, R; Bauer, J; Hai, T

    2001-08-01

    Activating transcription factor 3 (ATF3) is a member of the CREB/ATF family of transcription factors. Previously, we demonstrated that the expression of the ATF3 gene is induced by many stress signals. In this report, we demonstrate that expression of ATF3 is induced by cardiac ischemia coupled with reperfusion (ischemia-reperfusion) in both cultured cells and an animal model. Transgenic mice expressing ATF3 under the control of the alpha-myosin heavy chain promoter have atrial enlargement, and atrial and ventricular hypertrophy. Microscopic examination showed myocyte degeneration and fibrosis. Functionally, the transgenic heart has reduced contractility and aberrant conduction. Interestingly, expression of sorcin, a gene whose product inhibits the release of calcium from sarcoplasmic reticulum, is increased in these transgenic hearts. Taken together, our results indicate that expression of ATF3, a stress-inducible gene, in the heart leads to altered gene expression and impaired cardiac function. PMID:11485922

  19. BMI, HOMA-IR, and Fasting Blood Glucose Are Significant Predictors of Peripheral Nerve Dysfunction in Adult Overweight and Obese Nondiabetic Nepalese Individuals: A Study from Central Nepal.

    PubMed

    Thapa, Lekhjung; Rana, P V S

    2016-01-01

    Objective. Nondiabetic obese individuals have subclinical involvement of peripheral nerves. We report the factors predicting peripheral nerve function in overweight and obese nondiabetic Nepalese individuals. Methodology. In this cross-sectional study, we included 50 adult overweight and obese nondiabetic volunteers without features of peripheral neuropathy and 50 healthy volunteers to determine the normative nerve conduction data. In cases of abnormal function, the study population was classified on the basis of the number of nerves involved, namely, "<2" or "≥2." Multivariable logistic regression analysis was carried out to predict outcomes. Results. Fasting blood glucose (FBG) was the significant predictor of motor nerve dysfunction (P = 0.039, 95% confidence interval (CI) = 1.003-1.127). Homeostatic model assessment of insulin resistance (HOMA-IR) was the significant predictor (P = 0.019, 96% CI = 1.420-49.322) of sensory nerve dysfunction. Body mass index (BMI) was the significant predictor (P = 0.034, 95% CI = 1.018-1.577) in case of ≥2 mixed nerves' involvement. Conclusion. FBG, HOMA-IR, and BMI were significant predictors of peripheral nerve dysfunction in overweight and obese Nepalese individuals. PMID:27200189

  20. PHACE syndrome associated with congenital oculomotor nerve palsy.

    PubMed

    Murthy, Ramesh; Naik, Milind N; Desai, Savari; Honavar, Santosh G

    2009-01-01

    PHACE syndrome is a multisystem disorder presenting with facial hemangiomas, arterial anomalies, cardiac anomalies, posterior fossa malformations and eye abnormalities. The eye abnormalities include microphthalmos, cataracts, optic atrophy and iris hypoplasia. Amongst the neurological anomalies, posterior fossa malformations are common. Fourth nerve palsy has been reported with PHACE syndrome. We report a child presenting with a triad of congenital third nerve palsy, cerebellar hypoplasia and facial capillary hemangioma.

  1. Nerve Impulses in Plants

    ERIC Educational Resources Information Center

    Blatt, F. J.

    1974-01-01

    Summarizes research done on the resting and action potential of nerve impulses, electrical excitation of nerve cells, electrical properties of Nitella, and temperature effects on action potential. (GS)

  2. Upregulation of α1-adrenoceptors on cutaneous nerve fibres after partial sciatic nerve ligation and in complex regional pain syndrome type II.

    PubMed

    Drummond, Peter D; Drummond, Eleanor S; Dawson, Linda F; Mitchell, Vanessa; Finch, Philip M; Vaughan, Christopher W; Phillips, Jacqueline K

    2014-03-01

    After peripheral nerve injury, nociceptive afferents acquire an abnormal excitability to adrenergic agents, possibly due to an enhanced expression of α1-adrenoceptors (α1-ARs) on these nerve fibres. To investigate this in the present study, changes in α1-AR expression on nerve fibres in the skin and sciatic nerve trunk were assessed using immunohistochemistry in an animal model of neuropathic pain involving partial ligation of the sciatic nerve. In addition, α1-AR expression on nerve fibres was examined in painful and unaffected skin of patients who developed complex regional pain syndrome (CRPS) after a peripheral nerve injury (CRPS type II). Four days after partial ligation of the sciatic nerve, α1-AR expression was greater on dermal nerve fibres that survived the injury than on dermal nerve fibres after sham surgery. This heightened α1-AR expression was observed on nonpeptidergic nociceptive afferents in the injured sciatic nerve, dermal nerve bundles, and the papillary dermis. Heightened expression of α1-AR in dermal nerve bundles after peripheral nerve injury also colocalized with neurofilament 200, a marker of myelinated nerve fibres. In each patient examined, α1-AR expression was greater on nerve fibres in skin affected by CRPS than in unaffected skin from the same patient or from pain-free controls. Together, these findings provide compelling evidence for an upregulation of α1-ARs on cutaneous nociceptive afferents after peripheral nerve injury. Activation of these receptors by circulating or locally secreted catecholamines might contribute to chronic pain in CRPS type II.

  3. Luteolin improves the impaired nerve functions in diabetic neuropathy: behavioral and biochemical evidences.

    PubMed

    Li, Ming; Li, Qiang; Zhao, Qingsong; Zhang, Jinchao; Lin, Jiang

    2015-01-01

    Peripheral neuropathies are a major cause of morbidity in patients with diabetes mellitus. Up to now, drugs for improving the impaired nerve functions has been lacking for diabetic neuropathy. The antioxidant and neuroprotective effects of luteolin make it an attractive candidate for diabetic neuropathy. The present study was designed to investigate the putative beneficial effect of luteolin on diabetic neuropathy. Diabetic rats were intraperitoneally treated with daily luteolin (50 mg/kg, 100 mg/kg and 200 mg/kg) or vehicle for 3 weeks from the 28(th) day after streptozotocin injection. Behavioral, electrophysiological and biochemical studies were performed to evaluate the effect of luteolin on the impaired nerve functions in diabetic neuropathy. It was found that luteolin dose dependently alleviated abnormal sensation, improved nerve conduction velocities and nerve blood flow in diabetic rats. Biochanical analysis showed that luteolin significantly lowered the reactive oxygen species production and malondialdehyde level, as well as increased antioxidants activities in a dose dependent manner. In addition, luteolin significantly up-regulated the protein levels of nuclear factor-E2-related factor-2 (Nrf2) and heme oxygenase-1 (HO-1) in diabetic nerves. Taken together, luteolin is capable of improving diabetes-induced deficit in motor and sensory functions, which could be attributable, at least in part, to its Nrf2-dependent antioxidant capacity. The findings in the present study highlight the therapeutic value of luteolin for diabetic neuropathy.

  4. Luteolin improves the impaired nerve functions in diabetic neuropathy: behavioral and biochemical evidences

    PubMed Central

    Li, Ming; Li, Qiang; Zhao, Qingsong; Zhang, Jinchao; Lin, Jiang

    2015-01-01

    Peripheral neuropathies are a major cause of morbidity in patients with diabetes mellitus. Up to now, drugs for improving the impaired nerve functions has been lacking for diabetic neuropathy. The antioxidant and neuroprotective effects of luteolin make it an attractive candidate for diabetic neuropathy. The present study was designed to investigate the putative beneficial effect of luteolin on diabetic neuropathy. Diabetic rats were intraperitoneally treated with daily luteolin (50 mg/kg, 100 mg/kg and 200 mg/kg) or vehicle for 3 weeks from the 28th day after streptozotocin injection. Behavioral, electrophysiological and biochemical studies were performed to evaluate the effect of luteolin on the impaired nerve functions in diabetic neuropathy. It was found that luteolin dose dependently alleviated abnormal sensation, improved nerve conduction velocities and nerve blood flow in diabetic rats. Biochanical analysis showed that luteolin significantly lowered the reactive oxygen species production and malondialdehyde level, as well as increased antioxidants activities in a dose dependent manner. In addition, luteolin significantly up-regulated the protein levels of nuclear factor-E2-related factor-2 (Nrf2) and heme oxygenase-1 (HO-1) in diabetic nerves. Taken together, luteolin is capable of improving diabetes-induced deficit in motor and sensory functions, which could be attributable, at least in part, to its Nrf2-dependent antioxidant capacity. The findings in the present study highlight the therapeutic value of luteolin for diabetic neuropathy. PMID:26617718

  5. [Suprascapular nerve entrapment].

    PubMed

    Fansa, H; Schneider, W

    2003-03-01

    Isolated compression of the suprascapular nerve is a rare entity, that is seldom considered in differential diagnosis of shoulder pain. Usually atrophy of supraspinatus and infraspinatus muscles is present, resulting in weakened abduction and external rotation of the shoulder. Mostly the patients do not note the paresis, but complain about a dull and burning pain over the dorsal shoulder region. In a proximal lesion (at level of the superior transverse scapular ligament) electromyography reveals changes in both muscles, while in a distal lesion (spinoglenoidal notch) only the infraspinatus shows a pathology. From 1996 to 2001 we diagnosed an isolated suprascapular entrapment in nine patients. Seven patients were operated: The ligament was removed and the nerve was neurolysed. The average age was 36 years. All patients showed pathological findings in electrophysiological and clinical examination. Five patients had an atrophy of both scapula muscles, two showed only infraspinatus muscle atrophy (one with a ganglion in the distal course of the nerve). Six patients were followed up. All showed an improvement. Pain disappeared and all patients were able to return to work and sport activities. Electrophysiological examination one year after operation revealed normal nerve conduction velocity. The number of motor units, however, showed a reduction by half compared to the healthy side. Lesions without history of trauma are usually caused by repetitive motion or posture. Weight lifting, volley ball and tennis promote the entrapment. Rarely a lesion (either idiopathic or due to external compression) is described for patients who underwent surgery. Patients with a ganglion or a defined cause of compression should be operated, patients who present without a distinct reason for compression should firstly be treated conservatively. Physiotherapy, antiphlogistic medication and avoiding of the pain triggering motion can improve the symptoms. However, if muscle atrophy is evident

  6. Notalgia paresthetica with a significant increase in the number of intradermal nerves.

    PubMed

    Inaloz, H Serhat; Kirtak, Necmettin; Erguven, H Gulcin; Karakok, Metin; Inaloz, Serap S

    2002-11-01

    Notalgia paresthetica is an isolated mononeuropathy involving the skin over or near the scapula. The cause remains unknown. We histologically observed a significant increase in the number of dermal nerves in a case of notalgia paresthetica. Immunohistochemical examination using a neural marker, S-100, positively stained the nerves. Interestingly, a biopsy from perilesional skin also showed an abnormal nerve proliferation. PMID:12484438

  7. Inferior alveolar nerve block: Alternative technique

    PubMed Central

    Thangavelu, K.; Kannan, R.; Kumar, N. Senthil

    2012-01-01

    Background: Inferior alveolar nerve block (IANB) is a technique of dental anesthesia, used to produce anesthesia of the mandibular teeth, gingivae of the mandible and lower lip. The conventional IANB is the most commonly used the nerve block technique for achieving local anesthesia for mandibular surgical procedures. In certain cases, however, this nerve block fails, even when performed by the most experienced clinician. Therefore, it would be advantageous to find an alternative simple technique. Aim and Objective: The objective of this study is to find an alternative inferior alveolar nerve block that has a higher success rate than other routine techniques. To this purpose, a simple painless inferior alveolar nerve block was designed to anesthetize the inferior alveolar nerve. Materials and Methods: This study was conducted in Oral surgery department of Vinayaka Mission's dental college Salem from May 2009 to May 2011. Five hundred patients between the age of 20 years and 65 years who required extraction of teeth in mandible were included in the study. Out of 500 patients 270 were males and 230 were females. The effectiveness of the IANB was evaluated by using a sharp dental explorer in the regions innervated by the inferior alveolar, lingual, and buccal nerves after 3, 5, and 7 min, respectively. Conclusion: This study concludes that inferior alveolar nerve block is an appropriate alternative nerve block to anesthetize inferior alveolar nerve due to its several advantages. PMID:25885503

  8. Neurophysiological approach to disorders of peripheral nerve.

    PubMed

    Crone, Clarissa; Krarup, Christian

    2013-01-01

    Disorders of the peripheral nerve system (PNS) are heterogeneous and may involve motor fibers, sensory fibers, small myelinated and unmyelinated fibers and autonomic nerve fibers, with variable anatomical distribution (single nerves, several different nerves, symmetrical affection of all nerves, plexus, or root lesions). Furthermore pathological processes may result in either demyelination, axonal degeneration or both. In order to reach an exact diagnosis of any neuropathy electrophysiological studies are crucial to obtain information about these variables. Conventional electrophysiological methods including nerve conduction studies and electromyography used in the study of patients suspected of having a neuropathy and the significance of the findings are discussed in detail and more novel and experimental methods are mentioned. Diagnostic considerations are based on a flow chart classifying neuropathies into eight categories based on mode of onset, distribution, and electrophysiological findings, and the electrophysiological characteristics in each type of neuropathy are discussed. PMID:23931776

  9. Cardiovascular effects of afferent renal nerve stimulation.

    PubMed

    Stella, A; Weaver, L; Golin, R; Genovesi, S; Zanchetti, A

    1987-01-01

    Electrical stimulation of afferent renal nerves elicits an increase in arterial pressure and heart rate. The hypertensive response is presumably due to the widespread activation of the sympathetic nervous system leading to peripheral vasoconstriction. Interestingly, the kidney does not appear involved in this reflex excitatory response to afferent renal nerve stimulation since changes in vascular conductances and excretory functions are equal in both the innervated and denervated kidney, and secondary to changes in renal perfusion pressure. In addition, no changes in renin release from either kidneys are observed during afferent renal nerve stimulation. It is likely that the electrical stimulation of afferent renal nerves activates other reflexes exerting an inhibitory influence on efferent renal nerve activity. Indeed, neural renorenal reflexes which tonically inhibit renal functions have clearly been demonstrated. Furthermore, preferential inhibition of efferent renal nerve activity by cardiopulmonary and sinoaortic receptors has recently been shown during activation of other visceral afferents.

  10. Secondary optic nerve tumors.

    PubMed

    Christmas, N J; Mead, M D; Richardson, E P; Albert, D M

    1991-01-01

    Secondary tumors of the optic nerve are more common than primary optic nerve tumors. The involvement of the optic nerve may arise from direct invasion from intraocular malignancies, from hematopoietic malignancy, from meningeal carcinomatosis, or from distant primary tumors. Orbital tumors rarely invade the optic nerve, and brain tumors involve it only in their late stages.

  11. Peripheral nerve disease in pregnancy.

    PubMed

    Klein, Autumn

    2013-06-01

    Neuropathies during pregnancy and the postpartum period are common and are usually due to compression around pregnancy and childbirth. The most common peripheral neuropathies are Bell's palsy, carpal tunnel syndrome (CTS), and lower extremity neuropathies. Although most neuropathies are usually reversible, associated disabilities or morbidities can limit functioning and require therapy. Nerve conduction study tests and imaging should only be considered if symptoms are unusual or prolonged. Some neuropathies may be associated with preeclampsia or an inherent underlying neuropathy that increases the risk of nerve injury. All neuropathies in pregnancy should be followed as some may be persistent and require follow-up. PMID:23563878

  12. Nerve Injuries in Athletes.

    PubMed

    Collins, K; Storey, M; Peterson, K; Nutter, P

    1988-01-01

    In brief: Nerve injuries in athletes may be serious and may delay or prevent an athlete's return to his or her sport. Over a two-year period, the authors evaluated the condition of 65 patients who had entrapments of a nerve or nerve root, documented with electromyography. They describe four case histories: Two patients had radial nerve entrapments, one caused by baseball pitching and the other by kayaking; one football player had combined suprascapular neuropathy and upper trunk brachial plexopathy; and one patient had carpal tunnel syndrome of a median nerve secondary to rowing. Sports-related peripheral nerve lesions of the lower extremity were not seen during the study period. Based on a literature review, the nerve injuries discussed represent the spectrum of nerve entrapments likely to be seen in US clinics. The authors conclude that peripheral nerve lesions should be considered in the differential diagnosis of sports injuries, particularly at the shoulder, elbow, and wrist.

  13. Cranial Nerve Disorders in Children: MR Imaging Findings.

    PubMed

    Hwang, Jae-Yeon; Yoon, Hye-Kyung; Lee, Jeong Hyun; Yoon, Hee Mang; Jung, Ah Young; Cho, Young Ah; Lee, Jin Seong; Yoon, Chong Hyun

    2016-01-01

    Cranial nerve disorders are uncommon disease conditions encountered in pediatric patients, and can be categorized as congenital, inflammatory, traumatic, or tumorous conditions that involve the cranial nerve itself or propagation of the disorder from adjacent organs. However, determination of the normal course, as well as abnormalities, of cranial nerves in pediatric patients is challenging because of the small caliber of the cranial nerve, as well as the small intracranial and skull base structures. With the help of recently developed magnetic resonance (MR) imaging techniques that provide higher spatial resolution and fast imaging techniques including three-dimensional MR images with or without the use of gadolinium contrast agent, radiologists can more easily diagnose disease conditions that involve the small cranial nerves, such as the oculomotor, abducens, facial, and hypoglossal nerves, as well as normal radiologic anatomy, even in very young children. If cranial nerve involvement is suspected, careful evaluation of the cranial nerves should include specific MR imaging protocols. Localization is an important consideration in cranial nerve imaging, and should cover entire pathways and target organs as much as possible. Therefore, radiologists should be familiar not only with the various diseases that cause cranial nerve dysfunction, and the entire course of each cranial nerve including the intra-axial nuclei and fibers, but also the technical considerations for optimal imaging of pediatric cranial nerves. In this article, we briefly review normal cranial nerve anatomy and imaging findings of various pediatric cranial nerve dysfunctions, as well as the technical considerations of pediatric cranial nerve imaging. Online supplemental material is available for this article. (©)RSNA, 2016. PMID:27399242

  14. Cranial Nerve Disorders in Children: MR Imaging Findings.

    PubMed

    Hwang, Jae-Yeon; Yoon, Hye-Kyung; Lee, Jeong Hyun; Yoon, Hee Mang; Jung, Ah Young; Cho, Young Ah; Lee, Jin Seong; Yoon, Chong Hyun

    2016-01-01

    Cranial nerve disorders are uncommon disease conditions encountered in pediatric patients, and can be categorized as congenital, inflammatory, traumatic, or tumorous conditions that involve the cranial nerve itself or propagation of the disorder from adjacent organs. However, determination of the normal course, as well as abnormalities, of cranial nerves in pediatric patients is challenging because of the small caliber of the cranial nerve, as well as the small intracranial and skull base structures. With the help of recently developed magnetic resonance (MR) imaging techniques that provide higher spatial resolution and fast imaging techniques including three-dimensional MR images with or without the use of gadolinium contrast agent, radiologists can more easily diagnose disease conditions that involve the small cranial nerves, such as the oculomotor, abducens, facial, and hypoglossal nerves, as well as normal radiologic anatomy, even in very young children. If cranial nerve involvement is suspected, careful evaluation of the cranial nerves should include specific MR imaging protocols. Localization is an important consideration in cranial nerve imaging, and should cover entire pathways and target organs as much as possible. Therefore, radiologists should be familiar not only with the various diseases that cause cranial nerve dysfunction, and the entire course of each cranial nerve including the intra-axial nuclei and fibers, but also the technical considerations for optimal imaging of pediatric cranial nerves. In this article, we briefly review normal cranial nerve anatomy and imaging findings of various pediatric cranial nerve dysfunctions, as well as the technical considerations of pediatric cranial nerve imaging. Online supplemental material is available for this article. (©)RSNA, 2016.

  15. Inner Ear Conductive Hearing Loss and Unilateral Pulsatile Tinnitus Associated with a Dural Arteriovenous Fistula: Case Based Review and Analysis of Relationship between Intracranial Vascular Abnormalities and Inner Ear Fluids

    PubMed Central

    Cassandro, Ettore; Cassandro, Claudia; Sequino, Giuliano; Scarpa, Alfonso; Petrolo, Claudio; Chiarella, Giuseppe

    2015-01-01

    While pulsatile tinnitus (PT) and dural arteriovenous fistula (DAVF) are not rarely associated, the finding of a conductive hearing loss (CHL) in this clinical picture is unusual. Starting from a case of CHL and PT, diagnosed to be due to a DAVF, we analyzed relationship between intracranial vascular abnormalities and inner ear fluids. DAVF was treated with endovascular embolization. Following this, there was a dramatic recovery of PT and of CHL, confirming their cause-effect link with DAVF. We critically evaluated the papers reporting this association. This is the first case of CHL associated with PT and DAVF. We describe the most significant experiences and theories reported in literature, with a personal analysis about the possible relationship between vascular intracranial system and labyrinthine fluids. In conclusion, we believe that this association may be a challenge for otolaryngologists. So we suggest to consider the possibility of a DAVF or other AVMs when PT is associated with CHL, without alterations of tympanic membrane and middle ear tests. PMID:26693371

  16. A Rare Stapes Abnormality

    PubMed Central

    Kanona, Hala; Virk, Jagdeep Singh; Kumar, Gaurav; Chawda, Sanjiv; Khalil, Sherif

    2015-01-01

    The aim of this study is to increase awareness of rare presentations, diagnostic difficulties alongside management of conductive hearing loss and ossicular abnormalities. We report the case of a 13-year-old female reporting progressive left-sided hearing loss and high resolution computed tomography was initially reported as normal. Exploratory tympanotomy revealed an absent stapedius tendon and lack of connection between the stapes superstructure and footplate. The footplate was fixed. Stapedotomy and stapes prosthesis insertion resulted in closure of the air-bone gap by 50 dB. A review of world literature was performed using MedLine. Middle ear ossicular discontinuity can result in significant conductive hearing loss. This can be managed effectively with surgery to help restore hearing. However, some patients may not be suitable or decline surgical intervention and can be managed safely conservatively. PMID:25628909

  17. Using Eggshell Membrane as Nerve Guide Channels in Peripheral Nerve Regeneration

    PubMed Central

    Farjah, Gholam Hossein; Heshmatian, Behnam; Karimipour, Mojtaba; Saberi, Ali

    2013-01-01

    Objective(s): The aim of this study was to evaluate the final outcome of nerve regeneration across the eggsell membrane (ESM) tube conduit in comparison with autograft. Materials and Methods: Thirty adult male rats (250-300 g) were randomized into (1) ESM conduit, (2) autograft, and (3) sham surgery groups. The eggs submerged in 5% acetic acid. The decalcifying membranes were cut into four pieces, rotated over the teflon mandrel and dried at 37°C. The left sciatic nerve was surgically cut. A 10-mm nerve segment was cut and removed. In the ESM group, the proximal and distal cut ends of the sciatic nerve were telescoped into the nerve guides. In the autograft group, the 10 mm nerve segment was reversed and used as an autologous nerve graft. All animals were evaluated by sciatic functional index (SFI) and electrophysiology testing. Results: The improvement in SFI from the first to the last evalution in ESM and autograft groups were evaluated. On days 49 and 60 post-operation, the mean SFI of ESM group was significantly greater than the autograft group (P< 0.05). On day 90, the mean nerve conduction velocity (NCV) of ESM group was greater than autograft group, although the difference was not statistically significant (P> 0.05). Conclusion: These findings demonstrate that ESM effectively enhances nerve regeneration and promotes functional recovery in injured sciatic nerve of rat. PMID:24106593

  18. Common peroneal nerve dysfunction

    MedlinePlus

    ... toe-out movements Tests of nerve activity include: Electromyography (EMG, a test of electrical activity in muscles) Nerve ... Peroneal neuropathy. In: Preston DC, Shapiro BE, eds. Electromyography and Neuromuscular Disorders . 3rd ed. Philadelphia, PA: Elsevier; ...

  19. Electromechanical Nerve Stimulator

    NASA Technical Reports Server (NTRS)

    Tcheng, Ping; Supplee, Frank H., Jr.; Prass, Richard L.

    1993-01-01

    Nerve stimulator applies and/or measures precisely controlled force and/or displacement to nerve so response of nerve measured. Consists of three major components connected in tandem: miniature probe with spherical tip; transducer; and actuator. Probe applies force to nerve, transducer measures force and sends feedback signal to control circuitry, and actuator positions force transducer and probe. Separate box houses control circuits and panel. Operator uses panel to select operating mode and parameters. Stimulator used in research to characterize behavior of nerve under various conditions of temperature, anesthesia, ventilation, and prior damage to nerve. Also used clinically to assess damage to nerve from disease or accident and to monitor response of nerve during surgery.

  20. Nerve Injuries in Athletes.

    ERIC Educational Resources Information Center

    Collins, Kathryn; And Others

    1988-01-01

    Over a two-year period this study evaluated the condition of 65 athletes with nerve injuries. These injuries represent the spectrum of nerve injuries likely to be encountered in sports medicine clinics. (Author/MT)

  1. Comparison of nerve, vessel, and cartilage grafts in promoting peripheral nerve regeneration.

    PubMed

    Firat, Cemal; Geyik, Ylmaz; Aytekin, Ahmet Hamdi; Gül, Mehmet; Kamşl, Suat; Yiğitcan, Birgül; Ozcan, Cemal

    2014-07-01

    Peripheral nerve injury primarily occurs due to trauma as well as factors such as tumors, inflammatory diseases, congenital deformities, infections, and surgical interventions. The surgical procedure to be performed as treatment depends on the etiology, type of injury, and the anatomic region. The goal of treatment is to minimize loss of function due to motor and sensory nerve loss at the distal part of the injury. Regardless of the cause of the injury, the abnormal nerve regeneration due to incomplete nerve regeneration, optimal treatment of peripheral nerve injuries should provide adequate coaptation of proximal and distal sides without tension, preserving the neurotrophic factors within the repair line. The gold standard for the treatment of nerve defects is the autograft; however, due to denervation of the donor site, scarring, and neuroma formation, many studies have aimed to develop simpler methods, better functional results, and less morbidity. In this study, a defect 1 cm in length was created on the sciatic nerve of rats. The rats were treated with the following procedures: group 1, autograft; group 2, allogeneic aorta graft; group 3, diced cartilage graft in allogeneic aorta graft; and group 4, tubularized cartilage graft in allogeneic aorta graft. Group 5 was the control group. The effects of cartilage tissue in nerve regeneration were evaluated by functional and histomorphological methods.Group 1, for which the repair was performed with an autograft, was evaluated to be the most similar to the control group. There was not a statistically significant difference in myelination and Schwann cell rates between group 2, in which an allogeneic aorta graft was used, and group 3, in which diced cartilage in an allogeneic aorta graft was used. In group 4, myelination and Schwann cell formation were observed; however, they were scattered and irregular, likely due to increased fibrosis.In all of the groups, nerve regeneration at various rates was observed both

  2. Abnormal cold perception in the lower limbs: a sensitive indicator for detection of polyneuropathy in patients with type 1 diabetes mellitus.

    PubMed

    Hyllienmark, L; Jonsson, B; Ekberg, K; Lindström, P

    2009-09-01

    Diabetic peripheral neuropathy differs in type 1 and type 2 diabetes. The aim of this study was to evaluate how signs and symptoms of neuropathy correlated with defects in motor and sensory nerve conduction velocity (MCV and SCV) and sensory perception thresholds in patients with type 1 diabetes. MCV and SCV in peroneal and sural nerves and vibratory, warm and cold perception thresholds (VPT, WPT, CPT) were evaluated in the lower limbs of 127 patients (42+/-7.9 years old, duration of diabetes, 16+/-11 years and HbA1c, 7.7+/-1.4%). The results were compared with clinical findings (neuropathy impairment assessment, NIA) and sensory symptoms (neurological symptom assessment, NSA). Sensory symptoms were present in 24% of patients, 91% had at least one abnormal finding in the neurological examination and 84% had abnormal nerve conduction. The greatest deviation from normal was observed for CPT on the dorsum of the foot and peroneal MCV. NIA and NSA correlated with all electrophysiological measurements in the foot and big toe. It is concluded that clinical findings correlate well with electrophysiological abnormalities in patients with type 1 diabetic neuropathy. An elevated CPT for the foot was the most pronounced sensory defect.

  3. Facial nerve paralysis after cervical traction.

    PubMed

    So, Edmund Cheung

    2010-10-01

    Cervical traction is a frequently used treatment in rehabilitation clinics for cervical spine problems. This modality works, in principle, by decompressing the spinal cord or its nerve roots by applying traction on the cervical spine through a harness placed over the mandible (Olivero et al., Neurosurg Focus 2002;12:ECP1). Previous reports on treatment complications include lumbar radicular discomfort, muscle injury, neck soreness, and posttraction pain (LaBan et al., Arch Phys Med Rehabil 1992;73:295-6; Lee et al., J Biomech Eng 1996;118:597-600). Here, we report the first case of unilateral facial nerve paralysis developed after 4 wks of intermittent cervical traction therapy. Nerve conduction velocity examination revealed a peripheral-type facial nerve paralysis. Symptoms of facial nerve paralysis subsided after prednisolone treatment and suspension of traction therapy. It is suspected that a misplaced or an overstrained harness may have been the cause of facial nerve paralysis in this patient. Possible causes were (1) direct compression by the harness on the right facial nerve near its exit through the stylomastoid foramen; (2) compression of the right external carotid artery by the harness, causing transient ischemic injury at the geniculate ganglion; or (3) coincidental herpes zoster virus infection or idiopathic Bell's palsy involving the facial nerve.

  4. Distal nerve entrapment following nerve repair.

    PubMed

    Schoeller, T; Otto, A; Wechselberger, G; Pommer, B; Papp, C

    1998-04-01

    Failure of nerve repair or poor functional outcome after reconstruction can be influenced by various causes. Besides improper microsurgical technique, fascicular malalignment and unphysiologic tension, we found in our clinical series that a subclinical nerve compression distal to the repair site can seriously impair regeneration. We concluded that the injured nerve, whether from trauma or microsurgical intervention, could be more susceptible to distal entrapment in the regenerative stage because of its disturbed microcirculation, swelling and the increase of regenerating axons followed by increased nerve volume. In two cases we found the regenerating nerve entrapped at pre-existing anatomical sites of narrowing resulting in impaired functional recovery. In both cases the surgical therapy was decompression of the distal entrapped nerve and this was followed by continued regeneration. Thorough clinical and electrophysiologic follow-up is necessary to detect such adverse compression effects and to distinguish between the various causes of failed regeneration. Under certain circumstances primary preventive decompression may be beneficial if performed at the time of nerve coaptation.

  5. Clinical and electrophysiological assessment of inferior alveolar nerve function after lateral nerve transposition.

    PubMed

    Nocini, P F; De Santis, D; Fracasso, E; Zanette, G

    1999-04-01

    Inferior alveolar nerve (IAN) transposition surgery may cause some degree of sensory impairment. Accurate and reproducible tests are mandatory to assess IAN conduction capacity following nerve transposition. In this study subjective (heat, pain and tactile-discriminative tests) and objective (electrophysiological) assessments were performed in 10 patients receiving IAN transposition (bilaterally in 8 cases) in order to evaluate any impairment of the involved nerves one year post-operatively. All patients reported a tingling, well-tolerated sensation in the areas supplied by the mental nerve with no anaesthesia or burning paresthesia. Tactile discrimination was affected the most (all but 1 patient). No action potential was recorded in 4 patients' sides (23.5%); 12 sides showed a decreased nerve conduction velocity (NCV) (70.5%) and 1 side normal NCV values (6%). There was no significant difference in NCV decrease between partial and total transposition sides, if examined separately. Nerve conduction findings were related 2-point discrimination scores, but not to changes in pain and heat sensitivity. These findings show that lateral nerve transposition, though resulting in a high percentage of minor IAN injuries, as determined by electrophysiological testing, provides a viable surgical procedure to allow implant placement in the posterior mandible without causing severe sensory complaints. Considering ethical and forensic implications, patients should be fully informed that a certain degree of nerve injury might be expected to occur from the procedure. Electrophysiological evaluation is a reliable way to assess the degree of IAN dysfunction, especially if combined with a clinical examination. Intraoperative monitoring of IAN conduction might help identify the pathogenetic mechanisms of nerve injury and the surgical steps that are most likely to harm nerve integrity. PMID:10219131

  6. Cnidarian Nerve Nets and Neuromuscular Efficiency.

    PubMed

    Satterlie, Richard A

    2015-12-01

    Cnidarians are considered "nerve net animals" even though their nervous systems include various forms of condensation and centralization. Yet, their broad, two-dimensional muscle sheets are innervated by diffuse nerve nets. Do the motor nerve nets represent a primitive organization of multicellular nervous systems, do they represent a consequence of radial symmetry, or do they offer an efficient way to innervate a broad, two-dimensional muscle sheet, in which excitation of the muscle sheet can come from multiple sites of initiation? Regarding the primitive nature of cnidarian nervous systems, distinct neuronal systems exhibit some adaptations that are well known in higher animals, such as the use of oversized neurons with increased speed of conduction, and condensation of neurites into nerve-like tracts. A comparison of neural control of two-dimensional muscle sheets in a mollusc and jellyfish suggests that a possible primitive feature of cnidarian neurons may be a lack of regional specialization into conducting and transmitting regions.

  7. Effects of Laser Irradiation on Peripheral Nerve

    NASA Astrophysics Data System (ADS)

    Baxter, G. D.; Chow, R.; Armati, P.; Bjordal, J. M.; Laakso, L.

    2009-06-01

    A literature review was undertaken to determine the electrophysiological effects of Laser Irradiation (LI) on peripheral mammalian nerves, as a means of elucidating the potential mechanisms underlying pain relief associated with laser therapy. Relevant computerized databases and reference lists were searched, and experts consulted for further articles. A total of 38 studies, comprising 82 separate experiments were identified. In human studies, all types of LI (red and infrared, pulsed and cw) slowed nerve conduction velocity, and reduced compound action potential of irradiated nerves. In animal studies, infrared LI suppressed conduction velocity, as well as noxious stimulation evoked potential. This review thus indicates the potential of laser irradiation to inhibit activity in peripheral nerves, and highlights one potential mechanism of action for laser-mediated pain relief.

  8. [A case of Moebius syndrome--electrophysiological studies of facial nerve and brainstem].

    PubMed

    Noro, H; Wakai, S; Ishikawa, Y; Okabe, M; Minami, R

    1991-11-01

    A five-year old boy was the product of a 40 week pregnancy by vertex presentation complicated only by threatened abortion at approximately 8 weeks gestation. Apgar score was 5 after one minute. At birth he was noted to have a generalized hypotonia associated with facial diplegia, small mandible, weak suck and swallow reflexes. Admission examination revealed small mandible, mask-like facial expression and mild mental retardation. Cranial nerve examination showed bilateral blepharoptosis and facial nerve palsies. Pupil reflexes were normal, but corneal reflexes were impaired bilaterally. Diplopia due to the left abducens nerve palsy was suggested. There was no atrophy of the tongue. Motor tone, strength, and deep tendon reflexes were normal. A normal 46 XY karyotype was present. The other clinical and laboratory findings were normal. MRI of the brain was unremarkable. The characteristics of electrophysiological studies were summarized as follows: 1) Auditory brainstem evoked responses demonstrated waveforms IV-V were abnormal because their amplitudes were less than 30% of wave I bilaterally. 2) Somatosensory evoked potentials documented by central conduction times from cervical region to sensory cortex were prolonged on both sides. 3) Facial nerve conduction velocity was calculated by evoked EMGs of the mentalis muscle electrically stimulated at two distal points over the marginal mandibular branch. MCV of the left side was reduced (34.2 m/sec). 4) The amplitude of the facial muscle potentials evoked by facial nerve stimulation was reduced on both sides. 5) Blink reflex responses documented by the latency difference of R1 responses between the two sides were prolonged.(ABSTRACT TRUNCATED AT 250 WORDS)

  9. Echocardiographic abnormalities in the mucopolysaccharide storage diseases.

    PubMed

    Gross, D M; Williams, J C; Caprioli, C; Dominguez, B; Howell, R R

    1988-01-01

    The mucopolysaccharide storage diseases express themselves clinically with a wide variety of abnormalities, including growth and mental retardation, skeletal abnormalities, clouded corneas, nerve compression syndromes, upper airway obstruction and cardiovascular involvement, to name the most common. In most cases the cause of early death is cardiorespiratory failure secondary to cardiovascular involvement and upper airway obstruction. The findings of cardiac ultrasound examination in 29 children, adolescents and young adults are presented. In addition to the previously well-described abnormalities of the mitral and aortic valves in several types of mucopolysaccharide storage disease, we report patchy involvement in some cases, 3 instances of asymmetric septal hypertrophy not previously reported in mucopolysaccharide storage diseases, cardiac involvement in half of our patients with Sanfilippo syndrome and a lack of age-related severity of cardiac involvement even within the specific syndromes. PMID:3122547

  10. Behavioral and electrophysiological recovery following cryogenic nerve injury.

    PubMed

    Kalichman, M W; Myers, R R

    1987-06-01

    Postthoracotomy pain can be reduced by cryoanalgesia of intercostal nerves. The technique involves focal freezing of peripheral nerves to interrupt pain pathways, producing immediate functional changes that recover as the nerves regenerate. To assess the time-course of functional changes that follow nerve injury, unilateral freeze lesions of sciatic nerve were induced in rats with a cryosurgical unit. The contralateral nerves were used as sham-operated controls. Following nerve injury, behavioral and electrophysiologic tests were repeated to 90 days. The acute effect of nerve injury was a decrease in behavioral measures of hind limb function (P less than 0.05), an increase in electrical threshold to elicit hind limb contraction (P less than 0.005), and an absence of stimulus-evoked compound action potential (P less than 0.005). Morphologic changes included substantial endoneurial edema associated with Wallerian degeneration. Remyelination occurred subsequently during the following 35 days. Although all physiologic measures returned toward normal, nerve conduction velocities were still much slower in the experimental group. In a second study, the long-term effects of cryogenic injury were compared with neurolytic injury with 10% procaine HCl, both of which produced a conduction velocity deficit that persisted at least 90 days after the initial injury. These behavioral and electrophysiologic results complement previous reports of morphologic deficits in the nerves including incomplete recovery of nerve fiber diameter and increased thickness of the perineurial sheath. PMID:3582553

  11. A Biosynthetic Nerve Guide Conduit Based on Silk/SWNT/Fibronectin Nanocomposite for Peripheral Nerve Regeneration

    PubMed Central

    Mottaghitalab, Fatemeh; Farokhi, Mehdi; Zaminy, Arash; Kokabi, Mehrdad; Soleimani, Masoud; Mirahmadi, Fereshteh

    2013-01-01

    As a contribution to the functionality of nerve guide conduits (NGCs) in nerve tissue engineering, here we report a conduit processing technique through introduction and evaluation of topographical, physical and chemical cues. Porous structure of NGCs based on freeze-dried silk/single walled carbon nanotubes (SF/SWNTs) has shown a uniform chemical and physical structure with suitable electrical conductivity. Moreover, fibronectin (FN) containing nanofibers within the structure of SF/SWNT conduits produced through electrospinning process have shown aligned fashion with appropriate porosity and diameter. Moreover, fibronectin remained its bioactivity and influenced the adhesion and growth of U373 cell lines. The conduits were then implanted to 10 mm left sciatic nerve defects in rats. The histological assessment has shown that nerve regeneration has taken places in proximal region of implanted nerve after 5 weeks following surgery. Furthermore, nerve conduction velocities (NCV) and more myelinated axons were observed in SF/SWNT and SF/SWNT/FN groups after 5 weeks post implantation, indicating a functional recovery for the injured nerves. With immunohistochemistry, the higher S-100 expression of Schwann cells in SF/SWNT/FN conduits in comparison to other groups was confirmed. In conclusion, an oriented conduit of biocompatible SF/SWNT/FN has been fabricated with acceptable structure that is particularly applicable in nerve grafts. PMID:24098649

  12. The role of median nerve terminal latency index in the diagnosis of carpal tunnel syndrome in comparison with other electrodiagnostic parameters

    PubMed Central

    Vahdatpour, Babak; Khosrawi, Saeid; Chatraei, Maryam

    2016-01-01

    Background: Carpal tunnel syndrome (CTS) considers the most common compression neuropathy, which nerve conduction studies (NCSs) used for its detection routinely and universally. This study was performed to determine the value of the median TLI and other NCS variables and to investigate their sensitivity and specificity in the diagnosis of CTS. Materials and Methods: The study was carried out among 100 hands of healthy volunteers and 50 hands of patients who had a positive history of paresthesia and numbness in upper extremities. Information including age, gender, and result of sensory and motor nerve conduction velocity (MNCV), peak latency difference of median and ulnar nerves of fourth digit (M4-U4 peak latency difference), and TLI were recorded for analysis. Sensitivity and specificity of electro diagnostic parameters in the diagnosis of CTS was investigated. Results: Normal range of the median nerve TLI was 0.43 ± 0.077. There was no significant difference between two groups for MNCV means (P = 0. 45). Distal sensory latency and distal motor latency (DML) of median nerve and fourth digit median-ulnar peak latency differences (PM4-PU4) for CTS group was significantly higher (P < 0.001) and mean for sensory nerve conduction velocity was significantly higher in control group (P < 0.001). The most sensitive electrophysiological finding in CTS patients was median TLI (82%), but the most specific one was DML (98%). Conclusion: Although in early stages of CTS, we usually expect only abnormalities in the sensory studies, but TLI may better demonstrate the effect on median nerve motor fiber even in mild cases of CTS. PMID:27376049

  13. Accessory Upper Subscapular Nerve – The Neurotisation Tool

    PubMed Central

    Deshmukh, Vishwajit Ravindra; Mandal, Rabindra Prasad; Kusuma, Harisha

    2016-01-01

    During the routine dissection classes for undergraduate students, uncommon variation in relation to the upper subscapular nerve of posterior cord of brachial plexus was observed. Normally upper subscapular nerve takes origin from the posterior cord, but in this case report, it arises in triplet fashion, just above the circumflex scapular artery. All these accessory nerves were supplying upper part of the subscapularis muscle. As per our knowledge, this is a rare variation of brachial plexus. Many variations are encountered in the formation of brachial plexus. The normal and the abnormal origin of nerves are important considering neurotisation surgeries as well as during the infraclavicular nerve block for various axillary and upper limb surgeries. PMID:27790416

  14. The Furcal Nerve Revisited

    PubMed Central

    Dabke, Harshad V.

    2014-01-01

    Atypical sciatica and discrepancy between clinical presentation and imaging findings is a dilemma for treating surgeon in management of lumbar disc herniation. It also constitutes ground for failed back surgery and potential litigations thereof. Furcal nerve (Furcal = forked) is an independent nerve with its own ventral and dorsal branches (rootlets) and forms a link nerve that connects lumbar and sacral plexus. Its fibers branch out to be part of femoral and obturator nerves in-addition to the lumbosacral trunk. It is most commonly found at L4 level and is the most common cause of atypical presentation of radiculopathy/sciatica. Very little is published about the furcal nerve and many are unaware of its existence. This article summarizes all the existing evidence about furcal nerve in English literature in an attempt to create awareness and offer insight about this unique entity to fellow colleagues/professionals involved in spine care. PMID:25317309

  15. Direct Cranial Nerve Involvement by Gliomas: Case Series and Review of the Literature.

    PubMed

    Mabray, M C; Glastonbury, C M; Mamlouk, M D; Punch, G E; Solomon, D A; Cha, S

    2015-07-01

    Malignant gliomas are characterized by infiltrative growth of tumor cells, including along white matter tracts. This may result in clinical cranial neuropathy due to direct involvement of a cranial nerve rather than by leptomeningeal spread along cranial nerves. Gliomas directly involving cranial nerves III-XII are rare, with only 11 cases reported in the literature before 2014, including 8 with imaging. We present 8 additional cases demonstrating direct infiltration of a cranial nerve by a glioma. Asymmetric cisternal nerve expansion compared with the contralateral nerve was noted with a mean length of involvement of 9.4 mm. Based on our case series, the key imaging feature for recognizing direct cranial nerve involvement by a glioma is the detection of an intra-axial mass in the pons or midbrain that is directly associated with expansion, signal abnormality, and/or enhancement of the adjacent cranial nerves.

  16. Electrophysiology of corneal cold receptor nerve terminals.

    PubMed

    Carr, Richard W; Brock, James A

    2002-01-01

    The mechanisms of sensory transduction in the fine nerve terminals of free nerve endings supplied by Adelta and C sensory axons are largely a matter of speculation. This is because the nerve terminals are small and inaccessible, particularly in intact tissues like skin. However, some of the difficulties associated with investigating the physiology of fine nerve terminals have recently been overcome using an in vitro preparation of the guinea-pig cornea that allows nerve terminal impulses (NTIs) to be recorded extracellularly from single polymodal and cold receptor nerve terminals. For cold receptors, the rate of spontaneously occurring NTIs is increased during cooling and decreased during heating. In addition, heating and cooling differentially modulate the shape of the recorded NTI. At the same temperature, NTIs are larger in amplitude and faster in time course during heating than those during cooling. The differential effect of heating and cooling on NTI shape is not considered to result simply from the temperature dependence of voltage-activated conductance kinetics or activity dependent changes in membrane excitability. Instead, changes in NTI shape may reflect changes in nerve terminal membrane potential that underlie the process of thermal transduction.

  17. Simultaneous Quantification of Unmyelinated Nerve Fibers in Sural Nerve and in Skin.

    PubMed

    Duchesne, Mathilde; Magy, Laurent; Richard, Laurence; Ingrand, Pierre; Neau, Jean-Philippe; Mathis, Stéphane; Vallat, Jean-Michel

    2016-01-01

    Peripheral polyneuropathies are common and their diagnosis may be challenging. We compared the results from sural-nerve and skin biopsies in 33 patients with a polyneuropathy and neuropathic pain examined in our hospital over a 6-year period. The biopsies were all from the same lower limb of each patient. Intraepidermal nerve fiber (IENF) densities in the skin were determined by fluorescence microscopy; unmyelinated fiber densities in sural-nerve biopsies (UFNB) were determined by electron microscopy. There was no correlation with age or gender in either biopsy type; there was a weak trend to correlation between UFNB density and IENF density, possibly because of the small sample size. The sensitivity of detection of quantitative abnormalities of unmyelinated fibers was better in the skin than in the nerves. Proximal and distal IENF densities were strongly correlated; and counts of UFNB were highly reproducible. Thus, quantification of unmyelinated fibers in sural-nerve and skin biopsies seem to be complementary. Sural-nerve biopsy may be required to confirm a specific diagnosis, to identify lesion mechanisms, and to devise therapeutic strategies, whereas skin biopsy seems to be more efficient in the follow-up of length-dependent polyneuropathies and in the diagnosis of neuropathic pain.

  18. Abnormal Neuroimaging in a Case of Infant Botulism.

    PubMed

    Good, Ryan J; Messacar, Kevin; Stence, Nicholas V; Press, Craig A; Carpenter, Todd C

    2015-01-01

    We present the first case of abnormal neuroimaging in a case of infant botulism. The clinical findings of the patient with constipation, bulbar weakness, and descending, symmetric motor weakness are consistent with the classic findings of infant botulism. Magnetic resonance imaging (MRI), however, revealed restricted diffusion in the brain and enhancement of the cervical nerve roots. Traditionally, normal neuroimaging was used to help differentiate infant botulism from other causes of weakness in infants. Abnormal neuroimaging is seen in other causes of weakness in an infant including metabolic disorders and hypoxic-ischemic injury, but these diagnoses did not fit the clinical findings in this case. The explanation for the MRI abnormalities in the brain and cervical nerve roots is unclear as botulinum toxin acts at presynaptic nerve terminals and does not cross the blood-brain barrier. Possible explanations for the findings include inflammation from the botulinum toxin at the synapse, alterations in sensory signaling and retrograde transport of the botulinum toxin. The patient was treated with human botulism immune globulin and had rapid recovery in weakness. A stool sample from the patient was positive for Type A Clostridium botulinum toxin eventually confirming the diagnosis of infant botulism. The findings in this case support use of human botulism immune globulin when the clinical findings are consistent with infant botulism despite the presence of MRI abnormalities in the brain and cervical nerve roots. PMID:26697417

  19. Abnormal Neuroimaging in a Case of Infant Botulism

    PubMed Central

    Good, Ryan J.; Messacar, Kevin; Stence, Nicholas V.; Press, Craig A.; Carpenter, Todd C.

    2015-01-01

    We present the first case of abnormal neuroimaging in a case of infant botulism. The clinical findings of the patient with constipation, bulbar weakness, and descending, symmetric motor weakness are consistent with the classic findings of infant botulism. Magnetic resonance imaging (MRI), however, revealed restricted diffusion in the brain and enhancement of the cervical nerve roots. Traditionally, normal neuroimaging was used to help differentiate infant botulism from other causes of weakness in infants. Abnormal neuroimaging is seen in other causes of weakness in an infant including metabolic disorders and hypoxic–ischemic injury, but these diagnoses did not fit the clinical findings in this case. The explanation for the MRI abnormalities in the brain and cervical nerve roots is unclear as botulinum toxin acts at presynaptic nerve terminals and does not cross the blood–brain barrier. Possible explanations for the findings include inflammation from the botulinum toxin at the synapse, alterations in sensory signaling and retrograde transport of the botulinum toxin. The patient was treated with human botulism immune globulin and had rapid recovery in weakness. A stool sample from the patient was positive for Type A Clostridium botulinum toxin eventually confirming the diagnosis of infant botulism. The findings in this case support use of human botulism immune globulin when the clinical findings are consistent with infant botulism despite the presence of MRI abnormalities in the brain and cervical nerve roots. PMID:26697417

  20. Neurologic complication after anterior sciatic nerve block.

    PubMed

    Shah, Shruti; Hadzic, Admir; Vloka, Jerry D; Cafferty, Maureen S; Moucha, Calin S; Santos, Alan C

    2005-05-01

    The lack of reported complications related to lower extremity peripheral nerve blocks (PNBs) may be related to the relatively infrequent application of these techniques and to the fact that most such events go unpublished. Our current understanding of the factors that lead to neurologic complications after PNBs is limited. This is partly the result of our inability to conduct meaningful retrospective studies because of a lack of standard and objective monitoring and documentation procedures for PNBs. We report a case of permanent injury to the sciatic nerve after sciatic nerve block through the anterior approach and discuss mechanisms that may have led to the injury. Intraneural injection and nerve injury can occur in the absence of pain on injection and it may be heralded by high injection pressure (resistance).

  1. Mapping the Nerve Architecture of Diabetic Human Corneas

    PubMed Central

    He, Jiucheng; Bazan, Haydee E.P.

    2012-01-01

    Purpose Objective To investigate the entire human corneal nerve architecture of donors with different durations of insulin-dependent diabetes mellitus (IDDM). Design Experimental study. Participants and Controls Sixteen fresh human eyes from 8 diabetic donors (aged 43–66 years old, with IDDM for 2–17 years), and 12 eyes from 6 normal donors (aged from 44–67 years old) were obtained from National Disease Research Interchange (NDRI). Methods After fixation, corneas were stained with mouse monoclonal anti-β tubulin III antibody and images were acquired to build a whole view of the corneal nerve architecture. The same corneas were used for both whole mount and cross-section examination. Main outcome measures Corneal epithelial nerve density was calculated based on the whole mount view of the central area. The number of stromal nerves was calculated by counting the nerve trunks at the corneo-scleral limbus of the entire cornea. Differences between diabetic and normal corneas in epithelial nerve densities and main stromal nerve numbers were compared by paired-samples t test. Results The diabetic eyes presented numerous neuropathies in areas where the epithelial nerve bundles emerged. A striking pathologic change was the presence of abundant nerve fiber loops in the stroma. These loops seemed to form by resistance presented by the basement membrane, which may prevent penetration of stromal nerve branches into epithelia. There was no difference in the numbers of main stromal nerve trunks between corneas from diabetic and normal donors, but there was a significant decrease in central epithelial nerve density in the diabetic corneas. We did not find an age effect on this decrease. Instead, it was significantly affected by 5 or more years of IDDM. Conclusions This is the first study showing an entire view of the nerve architecture in human diabetic corneas. The decreased epithelial nerve density may result from the abnormalities of stromal nerve architecture and is

  2. Causes of Secondary Radial Nerve Palsy and Results of Treatment

    PubMed Central

    Reichert, Paweł; Wnukiewicz, Witold; Witkowski, Jarosław; Bocheńska, Aneta; Mizia, Sylwia; Gosk, Jerzy; Zimmer, Krzysztof

    2016-01-01

    Background The aim of this study was to analyze the causes that lead to secondary damage of the radial nerve and to discuss the results of reconstructive treatment. Material/Methods The study group consisted of 33 patients treated for radial nerve palsy after humeral fractures. Patients were diagnosed based on clinical examinations, ultrasonography, electromyography, or nerve conduction velocity. During each operation, the location and type of nerve damage were analyzed. During the reconstructive treatment, neurolysis, direct neurorrhaphy, or reconstruction with a sural nerve graft was used. The outcomes were evaluated using the Medical Research Council (MRC) scales and the quick DASH score. Results Secondary radial nerve palsy occurs after open reduction and internal fixation (ORIF) by plate, as well as by closed reduction and internal fixation (CRIF) by nail. In the case of ORIF, it most often occurs when the lateral approach is used, as in the case of CRIF with an insertion interlocking screws. The results of the surgical treatment were statistically significant and depended on the time between nerve injury and revision (reconstruction) surgery, type of damage to the radial nerve, surgery treatment, and type of fixation. Treatment results were not statistically significant, depending on the type of fracture or location of the nerve injury. Conclusions The potential risk of radial nerve neurotmesis justifies an operative intervention to treat neurological complications after a humeral fracture. Adequate surgical treatment in many of these cases allows for functional recovery of the radial nerve. PMID:26895570

  3. Inferior alveolar nerve repositioning.

    PubMed

    Louis, P J

    2001-09-01

    Nerve repositioning is a viable alternative for patients with an atrophic edentulous posterior mandible. Patients, however, should be informed of the potential risks of neurosensory disturbance. Documentation of the patient's baseline neurosensory function should be performed with a two-point discrimination test or directional brush stroke test preoperatively and postoperatively. Recovery of nerve function should be expected in 3 to 6 months. The potential for mandibular fracture when combining nerve repositioning with implant placement also should be discussed with the patient. This can be avoided by minimizing the amount of buccal cortical plate removal during localization of the nerve and maintaining the integrity of the inferior cortex of the mandible. Additionally, avoid overseating the implant, thus avoiding stress along the inferior border of the mandible. The procedure does allow for the placement of longer implants, which should improve implant longevity. Patients undergoing this procedure have expressed overall satisfaction with the results. Nerve repositioning also can be used to preserve the inferior alveolar nerve during resection of benign tumors or cysts of the mandible. This procedure allows the surgeon to maintain nerve function in situations in which the nerve would otherwise have to be resected. PMID:11665379

  4. Cryotherapy and nerve palsy.

    PubMed

    Drez, D; Faust, D C; Evans, J P

    1981-01-01

    Ice application is one of the most extensively used treatments for athletic injuries. Frostbite is a recognized danger. Five cases of nerve palsy resulting from ice application are reported here. These palsies were temporary. They usually resolve spontaneously without any significant sequelae. This complication can be avoided by not using ice for more than 30 minutes and by guarding superficial nerves in the area.

  5. Imaging the cranial nerves.

    PubMed

    Parry, Andrew T; Volk, Holger A

    2011-01-01

    An understanding of the normal course of the cranial nerves (CN) is essential when interpreting images of patients with cranial neuropathies. CN foramina are depicted best using computed X-ray tomography, but the nerves are depicted best using magnetic resonance imaging. The function and anatomy of the CN in the dog are reviewed and selected examples of lesions affecting the CN are illustrated.

  6. [Sciatic nerve intraneural perineurioma].

    PubMed

    Bonhomme, Benjamin; Poussange, Nicolas; Le Collen, Philippe; Fabre, Thierry; Vital, Anne; Lepreux, Sébastien

    2015-12-01

    Intraneural perineurioma is a benign tumor developed from the perineurium and responsible for localized nerve hypertrophy. This uncommon tumor is characterized by a proliferation of perineural cells with a "pseudo-onion bulb" pattern. We report a sciatic nerve intraneural perineurioma in a 39-year-old patient. PMID:26586011

  7. Optic Nerve Decompression

    MedlinePlus

    ... canals). The optic nerve is the “nerve of vision” and extends from the brain, through your skull, and into your eye. A ... limited to, the following: loss of vision, double vision, inadequate ... leakage of brain fluid (CSF), meningitis, nasal bleeding, infection of the ...

  8. A study of axonal degeneration in the optic nerves of aging mice

    NASA Technical Reports Server (NTRS)

    Johnson, J. E., Jr.; Philpott, D. E.; Miquel, J.

    1978-01-01

    The optic nerves of C57BL/6J mice ranging from 3 to 30 months were examined by electron microscopy. At all ages investigated, optic nerve axons contained enlarged mitochondria with abnormal cristae. With increasing age, a large number of necrotic axons were observed and were in the process of being phagocytized. The abnormal mitochondria may represent preliminary changes that eventually lead to necrosis of the axon.

  9. Ulnar nerve tuberculoma.

    PubMed

    Ramesh Chandra, V V; Prasad, Bodapati Chandramowliswara; Varaprasad, Gangumolu

    2013-01-01

    The authors report a very rare case of tuberculoma involving the ulnar nerve. The patient, a 7-year-old girl, presented with swelling over the medial aspect of her right forearm just below the elbow joint, with features of ulnar nerve palsy, including paresthesias along the little and ring fingers and claw hand deformity. There was a history of trauma and contact with a contagious case of tuberculosis. There were no other signs of tuberculosis. At surgical exploration the ulnar nerve was found to be thickened, and on opening the sheath there was evidence of caseous material enclosed in a fibrous capsule compressing and displacing the nerve fibers. The lesion, along with the capsule, was subtotally removed using curettage, and a part of the capsule that was densely adherent to the nerve fibers was left in the patient. Histopathological examination of the specimen was consistent with tuberculoma. The patient received adequate antitubercular treatment and showed significant improvement.

  10. Peripheral nerve stimulation: definition.

    PubMed

    Abejón, David; Pérez-Cajaraville, Juan

    2011-01-01

    Recently, there has been a tremendous evolution in the field of neurostimulation, both from the technological point of view and from development of the new and different indications. In some areas, such as peripheral nerve stimulation, there has been a boom in recent years due to the variations in the surgical technique and the improved results documented by in multiple published papers. All this makes imperative the need to classify and define the different types of stimulation that are used today. The confusion arises when attempting to describe peripheral nerve stimulation and subcutaneous stimulation. Peripheral nerve stimulation, in its pure definition, involves implanting a lead on a nerve, with the aim to produce paresthesia along the entire trajectory of the stimulated nerve.

  11. Construction of nerve guide conduits from cellulose/soy protein composite membranes combined with Schwann cells and pyrroloquinoline quinone for the repair of peripheral nerve defect.

    PubMed

    Luo, Lihua; Gan, Li; Liu, Yongming; Tian, Weiqun; Tong, Zan; Wang, Xiong; Huselstein, Celine; Chen, Yun

    2015-02-20

    Regeneration and functional reconstruction of peripheral nerve defects remained a significant clinical challenge. Nerve guide conduits, with seed cells or neurotrophic factors (NTFs), had been widely used to improve the repair and regeneration of injured peripheral nerve. Pyrroloquinoline quinone (PQQ) was an antioxidant that can stimulate nerve growth factors (NGFs) synthesis and accelerate the Schwann cells (SCs) proliferation and growth. In present study, three kinds of nerve guide conduits were constructed: one from cellulose/SPI hollow tube (CSC), another from CSC combined with SCs (CSSC), and the third one from CSSC combined with PQQ (CSSPC), respectively. And then they were applied to bridge and repair the sciatic nerve defect in rats, using autograft as control. Effects of different nerve guide conduits on the nerve regeneration were comparatively evaluated by general analysis, sciatic function index (SFI) and histological analysis (HE and TEM). Newly-formed regenerative nerve fibers were observed and running through the transparent nerve guide conduits 12 weeks after surgery. SFI results indicated that the reconstruction of motor function in CSSPC group was better than that in CSSC and CSC groups. HE images from the cross-sections and longitudinal-sections of the harvested regenerative nerve indicated that regenerative nerve fibers had been formed and accompanied with new blood vessels and matrix materials in the conduits. TEM images also showed that lots of fresh myelinated and non-myelinated nerve fibers had been formed. Parts of vacuolar, swollen and abnormal axons occurred in CSC and CSSC groups, while the vacuolization and swell of axons was the least serious in CSSPC group. These results indicated that CSSPC group had the most ability to repair and reconstruct the nerve structure and functions due to the comprehensive contributions from hollow CSC tube, SCs and PQQ. As a result, the CSSPC may have the potential for the applications as nerve guide

  12. Water excitation MPRAGE MRI of VII and VIII cranial nerves

    SciTech Connect

    Litt, A.W.; Licata, P.; Knopp, E.A.; Thomasson, D.M.

    1996-03-01

    Our goal was to compare magnetization prepared rapid gradient echo-water excitation (MPR-AGE-WE) with conventional spin echo (CSE) in the evaluation of the VII and VIII cranial nerves. One hundred three consecutive patients with symptoms referable to the VII/VIII nerves were studied with CSE T1 and MPRAGE-WE following intravenous gadolinium, contrast agent. Each right and left nerve pair was independently evaluated for the presence of an enhancing mass and for visualization of the nerves. On the CSE images, 26 definite and 2 possible lesions were identified, whereas 28 definite and 2 possible abnormalities were seen on the MPRAGE-WE. Four cases were better identified on the MPRAGE-WE and one better seen on the CSE. This difference was not statistically significant (p = 0. 19). CSE demonstrated the nerves partially in 23 instances and completely in 6; MPRAGE-WE showed the nerves partially in 35 and completely in 73. This was highly significant (p < 0.001). With equivalent or slightly improved lesion detection and better visualization of the nerves, MPRAGE-WE may replace CSE in studying the VII/VIII nerves. 14 refs., 7 figs., 3 tabs.

  13. Tooth - abnormal shape

    MedlinePlus

    Hutchinson incisors; Abnormal tooth shape; Peg teeth; Mulberry teeth; Conical teeth ... The appearance of normal teeth varies, especially the molars. ... conditions. Specific diseases can affect tooth shape, tooth ...

  14. Optic Nerve Monitoring

    PubMed Central

    Schumann, Paul; Kokemüller, Horst; Tavassol, Frank; Lindhorst, Daniel; Lemound, Juliana; Essig, Harald; Rücker, Martin; Gellrich, Nils-Claudius

    2013-01-01

    Orbital and anterior skull base surgery is generally performed close to the prechiasmatic visual pathway, and clear strategies for detecting and handling visual pathway damage are essential. To overcome the common problem of a missed clinical examination because of an uncooperative or unresponsive patient, flash visual evoked potentials and electroretinograms should be used. These electrophysiologic examination techniques can provide evidence of intact, pathologic, or absent conductivity of the visual pathway when clinical assessment is not feasible. Visual evoked potentials and electroretinograms are thus essential diagnostic procedures not only for primary diagnosis but also for intraoperative evaluation. A decision for or against treatment of a visual pathway injury has to be made as fast as possible due to the enormous importance of the time elapsed with such injuries; this can be achieved additionally using multislice spiral computed tomography. The first-line conservative treatment of choice for such injuries is megadose methylprednisolone therapy. Surgery is used to decompress the orbital compartment by exposure of the intracanalicular part of the optic nerve in the case of optic canal compression. Modern craniomaxillofacial surgery requires detailed consideration of the diagnosis and treatment of traumatic visual pathway damage with the ultimate goal of preserving visual acuity. PMID:24436741

  15. Six3 regulates optic nerve development via multiple mechanisms

    PubMed Central

    Samuel, Anat; Rubinstein, Ariel M.; Azar, Tehila T.; Ben-Moshe Livne, Zohar; Kim, Seok-Hyung; Inbal, Adi

    2016-01-01

    Malformations of the optic nerve lead to reduced vision or even blindness. During optic nerve development, retinal ganglion cell (RGC) axons navigate across the retina, exit the eye to the optic stalk (OS), and cross the diencephalon midline at the optic chiasm en route to their brain targets. Many signalling molecules have been implicated in guiding various steps of optic nerve pathfinding, however much less is known about transcription factors regulating this process. Here we show that in zebrafish, reduced function of transcription factor Six3 results in optic nerve hypoplasia and a wide repertoire of RGC axon pathfinding errors. These abnormalities are caused by multiple mechanisms, including abnormal eye and OS patterning and morphogenesis, abnormal expression of signalling molecules both in RGCs and in their environment and anatomical deficiency in the diencephalic preoptic area, where the optic chiasm normally forms. Our findings reveal new roles for Six3 in eye development and are consistent with known phenotypes of reduced SIX3 function in humans. Hence, the new zebrafish model for Six3 loss of function furthers our understanding of the mechanisms governing optic nerve development and Six3-mediated eye and forebrain malformations. PMID:26822689

  16. Purinergic nerves and receptors.

    PubMed

    Burnstock, G

    1980-01-01

    The presence of a non-cholinergic, non-adrenergic component in the vertebrate autonomic nervous system is now well established. Evidence that ATP is the transmitter released from some of these nerves (called "purinergic') includes: (a) synthesis and storage of ATP in nerves: (b) release of ATP from the nerves when they are stimulated; (c) exogenously applied ATP mimicking the action of nerve-released transmitter; (d) the presence of ectoenzymes which inactivate ATP; (e) drugs which produce similar blocking or potentiating effects on the response to exogenously applied ATP and nerve stimulation. A basis for distinguishing two types of purinergic receptors has been proposed according to four criteria: relative potencies of agonists, competitive antagonists, changes in levels of cAMP and induction of prostaglandin synthesis. Thus P1 purinoceptors are most sensitive to adenosine, are competitively blocked by methylxanthines and their occupation leads to changes in cAMP accumulation; while P2 purinoceptors are most sensitive to ATP, are blocked (although not competitively) by quinidine, 2-substituted imidazolines, 2,2'-pyridylisatogen and apamin, and their occupation leads to production of prostaglandin. P2 purinoceptors mediate responses of smooth muscle to ATP released from purinergic nerves, while P1 purinoceptors mediate the presynaptic actions of adenosine on adrenergic, cholinergic and purinergic nerve terminals. PMID:6108568

  17. Structurally abnormal human autosomes

    SciTech Connect

    1993-12-31

    Chapter 25, discusses structurally abnormal human autosomes. This discussion includes: structurally abnormal chromosomes, chromosomal polymorphisms, pericentric inversions, paracentric inversions, deletions or partial monosomies, cri du chat (cat cry) syndrome, ring chromosomes, insertions, duplication or pure partial trisomy and mosaicism. 71 refs., 8 figs.

  18. A novel Caspr mutation causes the shambling mouse phenotype by disrupting axoglial interactions of myelinated nerves.

    PubMed

    Sun, Xiao-yang; Takagishi, Yoshiko; Okabe, Erina; Chishima, Yûko; Kanou, Yasuhiko; Murase, Shiori; Mizumura, Kazue; Inaba, Mie; Komatsu, Yukio; Hayashi, Yoshitaka; Peles, Elior; Oda, Sen-ichi; Murata, Yoshiharu

    2009-11-01

    The neurological mouse mutation shambling (shm) exhibits ataxia and hindlimb paresis. Positional cloning of shm showed that it encodes contactin-associated protein (Caspr), which is required for formation of the paranodal junction in myelinated nerves. The shm mutation is a TT insertion in the Caspr gene that results in a frame shift and a premature stop codon at the COOH-terminus. The truncated Caspr protein that is generated lacks the transmembrane and cytoplasmic domains. Here, we found that the nodal/paranodal axoplasm of shm mice lack paranodal junctions and contain large mitochondria and abnormal accumulations of cytoplasmic organelles that indicate altered axonal transport. Immunohistochemical analysis of mutant mice showed reduced expression of Caspr, contactin, and neurofascin 155, which are thought to form a protein complex in the paranodal region; protein 4.1B, however, was normally distributed. The mutant mice had aberrant localization of voltage-gated ion channels on the axolemma of nodal/paranodal regions. Electrophysiological analysis demonstrated that the velocity of saltatory conduction was reduced in sciatic nerves and that the visual response was attenuated in the primary visual cortex. These abnormalities likely contribute to the neurological phenotype of the mutant mice. PMID:19816196

  19. Exacerbation of Charcot-Marie-Tooth type 2E neuropathy following traumatic nerve injury.

    PubMed

    Villalón, Eric; Dale, Jeffrey M; Jones, Maria; Shen, Hailian; Garcia, Michael L

    2015-11-19

    Charcot-Marie-Tooth disease (CMT) is the most commonly inherited peripheral neuropathy. CMT disease signs include distal limb neuropathy, abnormal gait, sensory defects, and deafness. We generated a novel line of CMT2E mice expressing hNF-L(E397K), which displayed muscle atrophy of the lower limbs without denervation, proximal reduction in large caliber axons, and decreased nerve conduction velocity. In this study, we challenged wild type, hNF-L and hNF-L(E397K) mice with crush injury to the sciatic nerve. We analyzed functional recovery by measuring toe spread and analyzed gait using the Catwalk system. hNF-L(E397K) mice demonstrated reduced recovery from nerve injury consistent with increased susceptibility to neuropathy observed in CMT patients. In addition, hNF-L(E397K) developed a permanent reduction in their ability to weight bear, increased mechanical allodynia, and premature gait shift in the injured limb, which led to increasingly disrupted interlimb coordination in hNF-L(E397K). Exacerbation of neuropathy after injury and identification of gait alterations in combination with previously described pathology suggests that hNF-L(E397K) mice recapitulate many of clinical signs associated with CMT2. Therefore, hNF-L(E397K) mice provide a model for determining the efficacy of novel therapies.

  20. Intraparotid facial nerve neurofibroma.

    PubMed

    Sullivan, M J; Babyak, J W; Kartush, J M

    1987-02-01

    Neurogenic neoplasms of the intraparotid facial nerve are uncommon and are usually diagnosed intraoperatively by tissue biopsy. Fifty-six cases of primary neurogenic neoplasms involving the facial nerve have been reported. The majority of these have been schwannomas. A case of a solitary neurofibroma involving the main trunk of the facial nerve is presented. Schwannomas and neurofibromas have distinct histological features which must be considered prior to the management of these tumors. The management of neurogenic tumors associated with normal facial function is a particularly difficult problem. A new approach for the diagnosis and management of neurogenic neoplasms is described utilizing electroneurography. PMID:3807626

  1. Radial Nerve Tendon Transfers.

    PubMed

    Cheah, Andre Eu-Jin; Etcheson, Jennifer; Yao, Jeffrey

    2016-08-01

    Radial nerve palsy typically occurs as a result of trauma or iatrogenic injury and leads to the loss of wrist extension, finger extension, thumb extension, and a reduction in grip strength. In the absence of nerve recovery, reconstruction of motor function involves tendon transfer surgery. The most common donor tendons include the pronator teres, wrist flexors, and finger flexors. The type of tendon transfer is classified based on the donor for the extensor digitorum communis. Good outcomes have been reported for most methods of radial nerve tendon transfers as is typical for positional tendon transfers not requiring significant power. PMID:27387076

  2. Physiological and pharmacologic aspects of peripheral nerve blocks

    PubMed Central

    Vadhanan, Prasanna; Tripaty, Debendra Kumar; Adinarayanan, S.

    2015-01-01

    A successful peripheral nerve block not only involves a proper technique, but also a thorough knowledge and understanding of the physiology of nerve conduction and pharmacology of local anesthetics (LAs). This article focuses on what happens after the block. Pharmacodynamics of LAs, underlying mechanisms of clinically observable phenomena such as differential blockade, tachyphylaxis, C fiber resistance, tonic and phasic blockade and effect of volume and concentration of LAs. Judicious use of additives along with LAs in peripheral nerve blocks can prolong analgesia. An entirely new group of drugs-neurotoxins has shown potential as local anesthetics. Various methods are available now to prolong the duration of peripheral nerve blocks. PMID:26330722

  3. Morphological abnormalities among lampreys

    USGS Publications Warehouse

    Manion, Patrick J.

    1967-01-01

    The experimental control of the sea lamprey (Petromyzon marinus) in the Great Lakes has required the collection of thousands of lampreys. Representatives of each life stage of the four species of the Lake Superior basin were examined for structural abnormalities. The most common aberration was the presence of additional tails. The accessory tails were always postanal and smaller than the normal tail. The point of origin varied; the extra tails occurred on dorsal, ventral, or lateral surfaces. Some of the extra tails were misshaped and curled, but others were normal in shape and pigment pattern. Other abnormalities in larval sea lampreys were malformed or twisted tails and bodies. The cause of the structural abnormalities is unknown. The presence of extra caudal fins could be genetically controlled, or be due to partial amputation or injury followed by abnormal regeneration. Few if any lampreys with structural abnormalities live to sexual maturity.

  4. High Ulnar Nerve Injuries: Nerve Transfers to Restore Function.

    PubMed

    Patterson, Jennifer Megan M

    2016-05-01

    Peripheral nerve injuries are challenging problems. Nerve transfers are one of many options available to surgeons caring for these patients, although they do not replace tendon transfers, nerve graft, or primary repair in all patients. Distal nerve transfers for the treatment of high ulnar nerve injuries allow for a shorter reinnervation period and improved ulnar intrinsic recovery, which are critical to function of the hand. PMID:27094893

  5. Nerve growth factor released from a novel PLGA nerve conduit can improve axon growth

    NASA Astrophysics Data System (ADS)

    Lin, Keng-Min; Shea, Jill; Gale, Bruce K.; Sant, Himanshu; Larrabee, Patti; Agarwal, Jay

    2016-04-01

    Nerve injury can occur due to penetrating wounds, compression, traumatic stretch, and cold exposure. Despite prompt repair, outcomes are dismal. In an attempt to help resolve this challenge, in this work, a poly-lactic-co-glycolic acid (PLGA) nerve conduit with associated biodegradable drug reservoir was designed, fabricated, and tested. Unlike current nerve conduits, this device is capable of fitting various clinical scenarios by delivering different drugs without reengineering the whole system. To demonstrate the potential of this device for nerve repair, a series of experiments were performed using nerve growth factor (NGF). First, an NGF dosage curve was developed to determine the minimum NGF concentration for optimal axonal outgrowth on chick dorsal root ganglia (DRG) cells. Next, PLGA devices loaded with NGF were evaluated for sustained drug release and axon growth enhancement with the released drug. A 20 d in vitro release test was conducted and the nerve conduit showed the ability to meet and maintain the minimum NGF requirement determined previously. Bioactivity assays of the released NGF showed that drug released from the device between the 15th and 20th day could still promote axon growth (76.6-95.7 μm) in chick DRG cells, which is in the range of maximum growth. These novel drug delivery conduits show the ability to deliver NGF at a dosage that efficiently promotes ex vivo axon growth and have the potential for in vivo application to help bridge peripheral nerve gaps.

  6. Facial Nerve Neuroma Management

    PubMed Central

    Weber, Peter C.; Osguthorpe, J. David

    1998-01-01

    Three facial nerve neuromas were identified in the academic year 1994-1995. Each case illustrates different management dilemmas. One patient with a grade III facial nerve palsy had a small geniculate ganglion neuroma with the dilemma of decompression versus resection clear nerve section margins. The second patient underwent facial neuroma resection with cable graft reconstruction, but the permanent sections were positive. The last patient had a massive neuroma in which grafting versus other facial reconstructive options were considered. These three cases illustrate some of the major controversies in facial nerve neuroma management. We discuss our decision-making plan and report our results. ImagesFigure 1Figure 2Figure 3Figure 4Figure 5 PMID:17171043

  7. Diabetes and nerve damage

    MedlinePlus

    Diabetic neuropathy; Diabetes - neuropathy; Diabetes - peripheral neuropathy ... In people with diabetes, the body's nerves can be damaged by decreased blood flow and a high blood sugar level. This condition is ...

  8. Vagus Nerve Stimulation

    PubMed Central

    Howland, Robert H.

    2014-01-01

    The vagus nerve is a major component of the autonomic nervous system, has an important role in the regulation of metabolic homeostasis, and plays a key role in the neuroendocrine-immune axis to maintain homeostasis through its afferent and efferent pathways. Vagus nerve stimulation (VNS) refers to any technique that stimulates the vagus nerve, including manual or electrical stimulation. Left cervical VNS is an approved therapy for refractory epilepsy and for treatment resistant depression. Right cervical VNS is effective for treating heart failure in preclinical studies and a phase II clinical trial. The effectiveness of various forms of non-invasive transcutaneous VNS for epilepsy, depression, primary headaches, and other conditions has not been investigated beyond small pilot studies. The relationship between depression, inflammation, metabolic syndrome, and heart disease might be mediated by the vagus nerve. VNS deserves further study for its potentially favorable effects on cardiovascular, cerebrovascular, metabolic, and other physiological biomarkers associated with depression morbidity and mortality. PMID:24834378

  9. Sacral nerve stimulation.

    PubMed

    Matzel, K E; Stadelmaier, U; Besendörfer, M

    2004-01-01

    The current concept of recruiting residual function of an inadequate pelvic organ by electrostimulation involves stimulation of the sacral spinal nerves at the level of the sacral canal. The rationale for applying SNS to fecal incontinence was based on clinical observations of its effect on bowel habits and anorectal continence function in urologic patients (increased anorectal angulation and anal canal closure pressure) and on anatomic considerations: dissection demonstrated a dual peripheral nerve supply of the striated pelvic floor muscles that govern these functions. Because the sacral spinal nerve site is the most distal common location of this dual nerve supply, stimulating here can elicit both functions. Since the first application of SNS in fecal incontinence in 1994, this technique has been improved, the patient selection process modified, and the spectrum of indications expanded. At present SNS has been applied in more than 1300 patients with fecal incontinence limited.

  10. Degenerative Nerve Diseases

    MedlinePlus

    Degenerative nerve diseases affect many of your body's activities, such as balance, movement, talking, breathing, and heart function. Many of these diseases are genetic. Sometimes the cause is a medical ...

  11. Damaged axillary nerve (image)

    MedlinePlus

    Conditions associated with axillary nerve dysfunction include fracture of the humerus (upper arm bone), pressure from casts or splints, and improper use of crutches. Other causes include systemic disorders that cause neuritis (inflammation of ...

  12. Iatrogenic accessory nerve injury.

    PubMed Central

    London, J.; London, N. J.; Kay, S. P.

    1996-01-01

    Accessory nerve injury produces considerable disability. The nerve is most frequently damaged as a complication of radical neck dissection, cervical lymph node biopsy and other surgical procedures. The problem is frequently compounded by a failure to recognise the error immediately after surgery when surgical repair has the greatest chance of success. We present cases which outline the risk of accessory nerve injury, the spectrum of clinical presentations and the problems produced by a failure to recognise the deficit. Regional anatomy, consequences of nerve damage and management options are discussed. Diagnostic biopsy of neck nodes should not be undertaken as a primary investigation and, when indicated, surgery in this region should be performed by suitably trained staff under well-defined conditions. Awareness of iatrogenic injury and its consequences would avoid delays in diagnosis and treatment. Images Figure 2 PMID:8678450

  13. Femoral nerve dysfunction

    MedlinePlus

    Neuropathy - femoral nerve; Femoral neuropathy ... Craig EJ, Clinchot DM. Femoral neuropathy. In: Frontera WR, Silver JK, Rizzo TD Jr, eds. Essentials of Physical Medicine and Rehabilitation: Musculoskeletal Disorders, Pain, and Rehabilitation . 3rd ...

  14. Diabetic Nerve Problems

    MedlinePlus

    ... the wrong times. This damage is called diabetic neuropathy. Over half of people with diabetes get it. ... change positions quickly Your doctor will diagnose diabetic neuropathy with a physical exam and nerve tests. Controlling ...

  15. Mandibular Branch of the Facial Nerve in Wistar Rats: New Experimental Model to Assess Facial Nerve Regeneration

    PubMed Central

    Bento, Ricardo Ferreira; Salomone, Raquel; Nascimento, Silvia Bona do; Ferreira, Ricardo Jose Rodriguez; Silva, Ciro Ferreira da; Costa, Heloisa Juliana Zabeu Rossi

    2014-01-01

    Introduction The ideal animal model for nerve regeneration studies is the object of controversy, because all models described by the literature have advantages and disadvantages. Objective To describe the histologic and functional patterns of the mandibular branch of the facial nerve of Wistar rats to create a new experimental model of facial nerve regeneration. Methods Forty-two male rats were submitted to a nerve conduction test of the mandibular branch to obtain the compound muscle action potential. Twelve of these rats had the mandibular branch surgically removed and submitted to histologic analysis (number, partial density, and axonal diameter) of the proximal and distal segments. Results There was no statistically significant difference in the functional and histologic variables studied. Conclusion These new histologic and functional standards of the mandibular branch of the facial nerve of rats establish an objective, easy, and greatly reproducible model for future facial nerve regeneration studies. PMID:25992106

  16. Construction of nerve guide conduits from cellulose/soy protein composite membranes combined with Schwann cells and pyrroloquinoline quinone for the repair of peripheral nerve defect

    SciTech Connect

    Luo, Lihua; Gan, Li; Liu, Yongming; Tian, Weiqun; Tong, Zan; Wang, Xiong; Huselstein, Celine; Chen, Yun

    2015-02-20

    Regeneration and functional reconstruction of peripheral nerve defects remained a significant clinical challenge. Nerve guide conduits, with seed cells or neurotrophic factors (NTFs), had been widely used to improve the repair and regeneration of injured peripheral nerve. Pyrroloquinoline quinone (PQQ) was an antioxidant that can stimulate nerve growth factors (NGFs) synthesis and accelerate the Schwann cells (SCs) proliferation and growth. In present study, three kinds of nerve guide conduits were constructed: one from cellulose/SPI hollow tube (CSC), another from CSC combined with SCs (CSSC), and the third one from CSSC combined with PQQ (CSSPC), respectively. And then they were applied to bridge and repair the sciatic nerve defect in rats, using autograft as control. Effects of different nerve guide conduits on the nerve regeneration were comparatively evaluated by general analysis, sciatic function index (SFI) and histological analysis (HE and TEM). Newly-formed regenerative nerve fibers were observed and running through the transparent nerve guide conduits 12 weeks after surgery. SFI results indicated that the reconstruction of motor function in CSSPC group was better than that in CSSC and CSC groups. HE images from the cross-sections and longitudinal-sections of the harvested regenerative nerve indicated that regenerative nerve fibers had been formed and accompanied with new blood vessels and matrix materials in the conduits. TEM images also showed that lots of fresh myelinated and non-myelinated nerve fibers had been formed. Parts of vacuolar, swollen and abnormal axons occurred in CSC and CSSC groups, while the vacuolization and swell of axons was the least serious in CSSPC group. These results indicated that CSSPC group had the most ability to repair and reconstruct the nerve structure and functions due to the comprehensive contributions from hollow CSC tube, SCs and PQQ. As a result, the CSSPC may have the potential for the applications as nerve guide

  17. Peripheral nerve injuries in athletes. Treatment and prevention.

    PubMed

    Lorei, M P; Hershman, E B

    1993-08-01

    Peripheral nerve lesions are uncommon but serious injuries which may delay or preclude an athlete's safe return to sports. Early, accurate anatomical diagnosis is essential. Nerve lesions may be due to acute injury (e.g. from a direct blow) or chronic injury secondary to repetitive microtrauma (entrapment). Accurate diagnosis is based upon physical examination and a knowledge of the relative anatomy. Palpation, neurological testing and provocative manoeuvres are mainstays of physical diagnosis. Diagnostic suspicion can be confirmed by electrophysiological testing, including electromyography and nerve conduction studies. Proper equipment, technique and conditioning are the keys to prevention. Rest, anti-inflammatories, physical therapy and appropriate splinting are the mainstays of treatment. In the shoulder, spinal accessory nerve injury is caused by a blow to the neck and results in trapezius paralysis with sparing of the sternocleidomastoid muscle. Scapular winging results from paralysis of the serratus anterior because of long thoracic nerve palsy. A lesion of the suprascapular nerve may mimic a rotator cuff tear with pain a weakness of the rotator cuff. Axillary nerve injury often follows anterior shoulder dislocation. In the elbow region, musculocutaneous nerve palsy is seen in weightlifters with weakness of the elbow flexors and dysesthesias of the lateral forearm. Pronator syndrome is a median nerve lesion occurring in the proximal forearm which is diagnosed by several provocative manoeuvres. Posterior interosseous nerve entrapment is common among tennis players and occurs at the Arcade of Froshe--it results in weakness of the wrist and metacarpophalangeal extensors. Ulnar neuritis at the elbow is common amongst baseball pitchers. Carpal tunnel syndrome is a common neuropathy seen in sport and is caused by median nerve compression in the carpal tunnel. Paralysis of the ulnar nerve at the wrist is seen among bicyclists resulting in weakness of grip and

  18. Abnormal uterine bleeding.

    PubMed

    Jennings, J C

    1995-11-01

    Physicians who care for female patients cannot avoid the frequent complaint of abnormal uterine bleeding. Knowledge of the disorders that cause this problem can prevent serious consequences in many patients and improve the quality of life for many others. The availability of noninvasive and minimally invasive diagnostic studies and minimally invasive surgical treatment has revolutionized management of abnormal uterine bleeding. Similar to any other disorder, the extent to which a physician manages abnormal uterine bleeding depends on his or her own level of comfort. When limitations of either diagnostic or therapeutic capability are encountered, consultation and referral should be used to the best interest of patients.

  19. Serial anthropometry predicts peripheral nerve dysfunction in a community cohort

    PubMed Central

    Ylitalo, Kelly R.; Herman, William H.; Harlow, Siobán D.

    2012-01-01

    Background Obesity is a risk factor for glucose intolerance, but the independent role of obesity in the development of peripheral neuropathy is unclear. This study assessed the impact of body size trajectories on prevalent nerve dysfunction in community-dwelling women with and without glucose intolerance. Methods Annual (1996–2008) anthropometric measures of weight, height, waist circumference, and body mass index (BMI, weight[kg]/height[m2]) were assessed in the Study of Women's Health Across the Nation – Michigan site. Glucose intolerance was defined annually based on current use of diabetes medications, self-reported diabetes diagnosis, and, when available, fasting glucose. Peripheral nerve dysfunction in 2008 was defined as abnormal monofilament testing or ≥4 symptoms or signs. Linear mixed models were used to determine trajectories of anthropometry by subsequently-identified nerve dysfunction status. Results Mean BMI was 32.4 kg/m2 at baseline and 27.8% of women had nerve dysfunction in 2008. BMI, weight, and waist circumference increased over time. Women who would have nerve dysfunction were significantly larger than women without dysfunction, independent of glucose intolerance. At mean baseline age of 46, BMI, weight, and waist circumference differed significantly (p-value<0.01) by subsequent nerve dysfunction status, independent of glucose intolerance and hypertension. These body size differences were maintained but not exacerbated over time. Conclusions Peripheral nerve dysfunction is prevalent among community-dwelling women. Twelve years before the nerve assessment, anthropometry differed between women who would and would not have nerve dysfunction, differences that were maintained over time. Obesity deserves attention as an important and potentially modifiable risk factor for peripheral nerve dysfunction. PMID:23161607

  20. Nerve Growth Factor and Diabetic Neuropathy

    PubMed Central

    Vinik, Aaron

    2003-01-01

    Neuropathy is one of the most debilitating complications of both type 1 and type 2 diabetes, with estimates of prevalence between 50–90% depending on the means of detection. Diabetic neuropathies are heterogeneous and there is variable involvement of large myelinated fibers and small, thinly myelinated fibers. Many of the neuronal abnormalities in diabetes can be duplicated by experimental depletion of specific neurotrophic factors, their receptors or their binding proteins. In experimental models of diabetes there is a reduction in the availability of these growth factors, which may be a consequence of metabolic abnormalities, or may be independent of glycemic control. These neurotrophic factors are required for the maintenance of the neurons, the ability to resist apoptosis and regenerative capacity. The best studied of the neurotrophic factors is nerve growth factor (NGF) and the related members of the neurotrophin family of peptides. There is increasing evidence that there is a deficiency of NGF in diabetes, as well as the dependent neuropeptides substance P (SP) and calcitonin gene-related peptide (CGRP) that may also contribute to the clinical symptoms resulting from small fiber dysfunction. Similarly, NT3 appears to be important for large fiber and IGFs for autonomic neuropathy. Whether the observed growth factor deficiencies are due to decreased synthesis, or functional, e.g. an inability to bind to their receptor, and/or abnormalities in nerve transport and processing, remains to be established. Although early studies in humans on the role of neurotrophic factors as a therapy for diabetic neuropathy have been unsuccessful, newer agents and the possibilities uncovered by further studies should fuel clinical trials for several generations. It seems reasonable to anticipate that neurotrophic factor therapy, specifically targeted at different nerve fiber populations, might enter the therapeutic armamentarium. PMID:14668049

  1. "Jeopardy" in Abnormal Psychology.

    ERIC Educational Resources Information Center

    Keutzer, Carolin S.

    1993-01-01

    Describes the use of the board game, Jeopardy, in a college level abnormal psychology course. Finds increased student interaction and improved application of information. Reports generally favorable student evaluation of the technique. (CFR)

  2. Abnormal Uterine Bleeding

    MedlinePlus

    ... Abnormal uterine bleeding is any bleeding from the uterus (through your vagina) other than your normal monthly ... or fibroids (small and large growths) in the uterus can also cause bleeding. Rarely, a thyroid problem, ...

  3. Abnormal Uterine Bleeding FAQ

    MedlinePlus

    ... as cancer of the uterus, cervix, or vagina • Polycystic ovary syndrome How is abnormal bleeding diagnosed? Your health care ... before the fetus can survive outside the uterus. Polycystic Ovary Syndrome: A condition characterized by two of the following ...

  4. Resolution of third nerve palsy despite persistent aneurysmal mass effect after flow diversion embolization of posterior communicating artery aneurysms.

    PubMed

    Binyamin, Tamar R; Dahlin, Brian C; Waldau, Ben

    2016-09-01

    Posterior communicating artery (PCOM) aneurysms may cause third nerve palsies. The optimal treatment with clipping versus coiling remains controversial. Here we report on two cases of resolution of third nerve palsy after flow diversion embolization of large and giant PCOM aneurysms without adjuvant coil placement. The resolution of third nerve palsy was not preceded by significant shrinkage of the aneurysmal sac on MRI. However, one patient showed resolution of T2-weighted signal abnormalities in the midbrain and mesial temporal lobe despite a similar size of the aneurysm. Therefore, flow diversion embolization of a PCOM aneurysm may resolve oculomotor nerve palsies through decreasing arterial pulsations against the nerve or midbrain. PMID:27183957

  5. Development of a scaffoldless three-dimensional engineered nerve using a nerve-fibroblast co-culture

    PubMed Central

    Baltich, Jennifer; Hatch-Vallier, Leah; Adams, Aaron M.; Arruda, Ellen M.; Larkin, Lisa M.

    2009-01-01

    Nerve grafts are often required to replace tissue damaged by disease, surgery, or extensive trauma. Limitations such as graft availability, donor site morbidity, and immune rejection have led investigators to develop strategies to engineer nerve tissue. The goal of this study was to fabricate a scaffoldless three-dimensional (3D) nerve construct using a co-culture of fetal nerve cells with a fibroblast monolayer and allow the co-culture to remodel into a 3D construct with an external fibroblast layer and an internal core of interconnected neuronal cells. Primary fibroblasts were seeded on laminin-coated plates and allowed to form a confluent monolayer. Neural cells isolated from E-15 spinal cords were seeded on top of the fibroblast monolayer and allowed to form a networked monolayer across the monolayer of fibroblasts. Media shifts initiated contraction of the fibroblast monolayer and a remodeling of the co-culture into a 3D construct held statically in place by the two constraint pins. Immunohisto-chemistry using S100 (Schwann cell), β3-tubulin, DAPI, and collagen I indicated an inner core of nerve cells surrounded by an external layer of fibroblasts. Conduction velocities of the 3D nerve and control (fibroblast-only) constructs were measured in vitro and compared to in vivo measures of neonatal sciatic nerve. The conduction velocities of the nerve constructs were comparable to 24-d-old neonatal nerve. The presence of Schwann cells and the ability to conduct neuronal signals in vitro suggest the scaffoldless 3D nerve constructs will be a viable option for nerve repair. PMID:19997868

  6. Early Electrophysiological Abnormalities and Clinical Neuropathy

    PubMed Central

    Hyllienmark, Lars; Alstrand, Nils; Jonsson, Björn; Ludvigsson, Johnny; Cooray, Gerald; Wahlberg-Topp, Jeanette

    2013-01-01

    OBJECTIVE The aim of this study was to elucidate whether subclinical nerve dysfunction as reflected by neurophysiological testing predicts the development of clinical neuropathy in patients with type 1 diabetes. RESEARCH DESIGN AND METHODS Fifty-nine patients were studied twice with neurophysiological measurements at baseline and at follow-up. At baseline, patients were 15.5 ± 3.22 years (range 7–22 years) of age, and duration of diabetes was 6.8 ± 3.3 years. At follow-up, patients were 20–35 years of age, and disease duration was 20 ± 5.3 years (range 10–31 years). RESULTS At baseline, patients showed modestly reduced nerve conduction velocities and amplitudes compared with healthy subjects, but all were free of clinical neuropathy. At follow-up, clinical neuropathy was present in nine (15%) patients. These patients had a more pronounced reduction in peroneal motor nerve conduction velocity (MCV), median MCV, and sural sensory nerve action potential at baseline (P < 0.010–0.003). In simple logistic regression analyses, the predictor with the strongest association with clinical neuropathy was baseline HbA1c (R2 = 48%, odds ratio 7.9, P < 0.002) followed by peroneal MCV at baseline (R2 = 38%, odds ratio 0.6, P < 0.006). With the use of a stepwise forward analysis that included all predictors, first baseline HbA1c and then only peroneal MCV at baseline entered significantly (R2 = 61%). Neuropathy impairment assessment showed a stronger correlation with baseline HbA1c (ρ = 0.40, P < 0.002) than with follow-up HbA1c (ρ = 0.034, P < 0.007). CONCLUSIONS Early defects in nerve conduction velocity predict the development of diabetic neuropathy. However, the strongest predictor was HbA1c during the first years of the disease. PMID:23723354

  7. Successful Reconstruction of Nerve Defects Using Distraction Neurogenesis with a New Experimental Device

    PubMed Central

    Yousef, Mohamed Abdelhamid Ali; Dionigi, Paolo; Marconi, Stefania; Calligaro, Alberto; Cornaglia, Antonia Icaro; Alfonsi, Enrico; Auricchio, Ferdinando

    2015-01-01

    Introduction: Repair of peripheral nerve injuries is an intensive area of challenge and research in modern reconstructive microsurgery. Intensive research is being carried out to develop effective alternatives to the standard nerve autografting, avoiding its drawbacks. The aim of the study was to evaluate the effectiveness of a newly designed mechanical device for the reconstruction of the sciatic nerve in rats in comparison to nerve autografting and to assess the pain during the period of distraction neurogenesis. Methods: Fourteen Sprague Dawley rats were used and randomly assigned into 2 groups with 7 rats in each group; group A (Nerve Autografting group) in which a 10-mm segment of the sciatic nerve was resected and rotated 180 degrees, then primary end-to-end neurorrhaphy was performed in the reverse direction; group B (Nerve Lengthening group) in which the mechanical device was inserted after surgical resection of 10 mm of the sciatic nerve, then secondary end-to-end neurorrhaphy was performed after completing the nerve lengthening. Thirteen weeks later, assessment of the functional sciatic nerve recovery using static sciatic index (SSI) was performed. Furthermore, fourteen weeks after the nerve resection, assessment of the nerve regeneration with electrophysiological study and histological analysis were performed. Also, gastrocnemius wet weight was measured. For pain assessment in group B, Rat Grimace Scale (RGS) score was used. Results: Significantly better functional recovery rate (using the SSI) was reported in the nerve lengthening group in comparison to autografting group. Also, a statistically significant higher nerve conduction velocity was detected in the nerve lengthening group. On histological analysis of the distal nerve section at 3 mm distal to the nerve repair site, significant myelin sheath thickness was detected in the nerve lengthening group. Discussion: Distraction neurogenesis with the new experimental device is a reliable therapeutic

  8. Communications Between the Facial Nerve and the Vestibulocochlear Nerve, the Glossopharyngeal Nerve, and the Cervical Plexus.

    PubMed

    Hwang, Kun; Song, Ju Sung; Yang, Su Cheol

    2015-10-01

    The aim of this review is to elucidate the communications between the facial nerves or facial nerve and neighboring nerves: the vestibulocochlear nerve, the glossopharyngeal nerve, and the cervical plexus.In a PubMed search, 832 articles were searched using the terms "facial nerve and communication." Sixty-two abstracts were read and 16 full-text articles were reviewed. Among them, 8 articles were analyzed.The frequency of communication between the facial nerve and the vestibulocochlear nerve was the highest (82.3%) and the frequency of communication between the facial nerve and the glossopharyngeal nerve was the lowest (20%). The frequency of communication between the facial nerve and the cervical plexus was 65.2 ± 43.5%. The frequency of communication between the cervical branch and the marginal mandibular branch of the facial nerve was 24.7 ± 1.7%.Surgeons should be aware of the nerve communications, which are important during clinical examinations and surgical procedures of the facial nerves such as those communications involved in facial reconstructive surgery, neck dissection, and various nerve transfer procedures.

  9. The effects of evening primrose oil on nerve function and capillarization in streptozotocin-diabetic rats: modulation by the cyclo-oxygenase inhibitor flurbiprofen.

    PubMed Central

    Cameron, N. E.; Cotter, M. A.; Dines, K. C.; Robertson, S.; Cox, D.

    1993-01-01

    1. The aims of this study were first, to examine whether deficits in nerve conduction in streptozotocin-diabetic rats could be reversed by a 10% dietary supplement of evening primrose oil. Second, to determine the time-course of reversal, and third, to assess whether the effects could be blocked by the cyclo-oxygenase inhibitor flurbiprofen (5 mg kg-1 day-1). 2. One-month diabetes produced 20% and 15% deficits in sciatic motor and saphenous sensory conduction velocity respectively, which were maintained over 2 months diabetes. 3. The effect of 1-month evening primrose oil treatment on abnormalities caused by an initial month of untreated diabetes was examined. Motor and sensory nerve conduction velocity were restored to the non-diabetic level. 4. Resistance to hypoxic conduction failure was investigated for sciatic nerve trunk in vitro. The 80% conduction failure times were 29% and 55% prolonged by 1- and 2-month diabetes respectively. Evening primrose oil did not reverse the increased hypoxic resistance following 1-month untreated diabetes. 5. Sciatic nerve endoneurial capillary density was not significantly affected by diabetes, but was 16% increased in diabetic rats with reversal by evening primrose oil treatment for 1 month compared to 2-month untreated diabetes. 6. Serial motor conduction velocity measurement after 3-month untreated diabetes revealed complete normalization by evening primrose oil within 4 days. Cessation of treatment resulted in a rapid decline in conduction velocity over 24 h. 7. In a preventive study of 2-month duration, 6 groups of rats were used.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8401950

  10. [Nerve ultrasound is useful for the diagnosis of neuromuscular diseases].

    PubMed

    Noto, Yu-Ichi

    2013-01-01

    High-resolution ultrasound allowed for more detailed morphological assessment peripheral nerves and muscles. It is important to elucidate ultrasound features of peripheral nerves or muscles in various neuromuscular diseases because ultrasound is a widely used, non-invasive and easily accessible diagnostic tool. We attempted to demonstrate characteristic findings of nerve ultrasound in patients with Charcot-Marie-Tooth disease (CMT), Amyotrophic lateral sclerosis (ALS), and Cervical radiculopathy. In patients with CMT1A, cross sectional areas (CSAs) of all the nerves we examined were significantly larger than those in normal controls. Additionally, median nerve CSA had positive correlation with CMT neuropathy score, and negative correlation with nerve conduction velocity. In patients with ALS, increased CSA forearm/upper arm ratio of the median nerve was a characteristic finding to support the diagnosis. In patients with cervical radiculopathy, we could observe that decreased CSA and diameter of the nerve root corresponding to the findings of MRI and electromyography. These results demonstrate that the combination of electrophysiological study, diagnostic imaging, and nerve ultrasound could lead to accurate diagnosis of various neuromuscular diseases.

  11. Clinical applications of diffusion magnetic resonance imaging of the lumbar foraminal nerve root entrapment

    PubMed Central

    Ohtori, Seiji; Yamashita, Masaomi; Yamauchi, Kazuyo; Suzuki, Munetaka; Orita, Sumihisa; Kamoda, Hiroto; Arai, Gen; Ishikawa, Tetsuhiro; Miyagi, Masayuki; Ochiai, Nobuyasu; Kishida, Shunji; Masuda, Yoshitada; Ochi, Shigehiro; Kikawa, Takashi; Takaso, Masashi; Aoki, Yasuchika; Toyone, Tomoaki; Suzuki, Takane; Takahashi, Kazuhisa

    2010-01-01

    Diffusion-weighted imaging (DWI) can provide valuable structural information about tissues that may be useful for clinical applications in evaluating lumbar foraminal nerve root entrapment. Our purpose was to visualize the lumbar nerve root and to analyze its morphology, and to measure its apparent diffusion coefficient (ADC) in healthy volunteers and patients with lumbar foraminal stenosis using 1.5-T magnetic resonance imaging. Fourteen patients with lumbar foraminal stenosis and 14 healthy volunteers were studied. Regions of interest were placed at the fourth and fifth lumbar root at dorsal root ganglia and distal spinal nerves (at L4 and L5) and the first sacral root and distal spinal nerve (S1) on DWI to quantify mean ADC values. The anatomic parameters of the spinal nerve roots can also be determined by neurography. In patients, mean ADC values were significantly higher in entrapped roots and distal spinal nerve than in intact ones. Neurography also showed abnormalities such as nerve indentation, swelling and running transversely in their course through the foramen. In all patients, leg pain was ameliorated after selective decompression (n = 9) or nerve block (n = 5). We demonstrated the first use of DWI and neurography of human lumbar nerves to visualize and quantitatively evaluate lumbar nerve entrapment with foraminal stenosis. We believe that DWI is a potential tool for diagnosis of lumbar nerve entrapment. PMID:20632042

  12. [Erythrocyte membrane abnormalities - hereditary elliptocytosis].

    PubMed

    Kvezereli-Kopadze, M; Kvezereli-Kopadze, A; Mtvarelidze, Z; Bubuteishvili, A

    2015-04-01

    This study was designed to investigate the 4 year old boy with Hereditary Elliptocitosis (HE). The diagnosis of this rare hemolytic anemia was based on detailed family history (positive in the 4-th generation), physical examination and Para-clinical data analyses. The vast majority of patients with HE are asymptomatic, severe forms are rare. The most important is examination of blood films, which is helpful to detect the morphology abnormalities of red cells. In case of HE a different approach is required. Positive family history and series of investigations should be conducted to determine the HE.

  13. Acellular Nerve Allografts in Peripheral Nerve Regeneration: A Comparative Study

    PubMed Central

    Moore, Amy M.; MacEwan, Matthew; Santosa, Katherine B.; Chenard, Kristofer E.; Ray, Wilson Z.; Hunter, Daniel A.; Mackinnon, Susan E.; Johnson, Philip J.

    2011-01-01

    Background Processed nerve allografts offer a promising alternative to nerve autografts in the surgical management of peripheral nerve injuries where short deficits exist. Methods Three established models of acellular nerve allograft (cold-preserved, detergent-processed, and AxoGen® -processed nerve allografts) were compared to nerve isografts and silicone nerve guidance conduits in a 14 mm rat sciatic nerve defect. Results All acellular nerve grafts were superior to silicone nerve conduits in support of nerve regeneration. Detergent-processed allografts were similar to isografts at 6 weeks post-operatively, while AxoGen®-processed and cold-preserved allografts supported significantly fewer regenerating nerve fibers. Measurement of muscle force confirmed that detergent-processed allografts promoted isograft-equivalent levels of motor recovery 16 weeks post-operatively. All acellular allografts promoted greater amounts of motor recovery compared to silicone conduits. Conclusions These findings provide evidence that differential processing for removal of cellular constituents in preparing acellular nerve allografts affects recovery in vivo. PMID:21660979

  14. Discrete impulses in ephaptically coupled nerve fibers.

    PubMed

    Maïna, I; Tabi, C B; Ekobena Fouda, H P; Mohamadou, A; Kofané, T C

    2015-04-01

    We exclusively analyze the condition for modulated waves to emerge in two ephaptically coupled nerve fibers. Through the multiple scale expansion, it is shown that a set of coupled cable-like Hodgkin-Huxley equations can be reduced to a single differential-difference nonlinear equation. The standard approach of linear stability analysis of a plane wave is used to predict regions of parameters where nonlinear structures can be observed. Instability features are shown to be importantly controlled not only by the ephaptic coupling parameter, but also by the discreteness parameter. Numerical simulations, to verify our analytical predictions, are performed, and we explore the longtime dynamics of slightly perturbed plane waves in the coupled nerve fibers. On initially exciting only one fiber, quasi-perfect interneuronal communication is discussed along with the possibility of recruiting damaged or non-myelinated nerve fibers, by myelinated ones, into conduction.

  15. [Suprascapular nerve entrapment in a basketball player].

    PubMed

    Tsur, A; Shahin, R

    1997-09-01

    A basketball player was shown to have a suprascapular nerve lesion without any history of shoulder girdle trauma. This acute neuropathy, never previously described in basketball players, is a result of repeated micro-trauma, due to nerve traction over the coracoid notch during violent movement ("dunking" most probably). Clinically, he was unable to abduct his arm and had some difficulty in external rotation. He developed atrophy in both the supra- and the infraspinatus muscles. Nerve conduction latency to the supraspinatus muscle was 8.0 ms, and to the infraspinatus, 8.5 ms. The compound muscle action potential registered in the supraspinatus was 1.224 mV, and in the infraspinatus, 1.237 mV. After 3 weeks of inactivity, recovery was spontaneous and practically complete.

  16. Neuromuscular ultrasound of cranial nerves.

    PubMed

    Tawfik, Eman A; Walker, Francis O; Cartwright, Michael S

    2015-04-01

    Ultrasound of cranial nerves is a novel subdomain of neuromuscular ultrasound (NMUS) which may provide additional value in the assessment of cranial nerves in different neuromuscular disorders. Whilst NMUS of peripheral nerves has been studied, NMUS of cranial nerves is considered in its initial stage of research, thus, there is a need to summarize the research results achieved to date. Detailed scanning protocols, which assist in mastery of the techniques, are briefly mentioned in the few reference textbooks available in the field. This review article focuses on ultrasound scanning techniques of the 4 accessible cranial nerves: optic, facial, vagus and spinal accessory nerves. The relevant literatures and potential future applications are discussed.

  17. High-Resolution Sonography: A New Technique to Detect Nerve Damage in Leprosy

    PubMed Central

    Jain, Suman; Visser, Leo H.; Praveen, T. L. N.; Rao, P. Narasimha; Surekha, Thummalakunta; Ellanti, Ramesh; Abhishek, Thummalakunta L. N.; Nath, Indira

    2009-01-01

    Background Leprosy is the most common treatable peripheral nerve disorder worldwide with periods of acute neuritis leading to functional impairment of limbs, ulcer formation and stigmatizing deformities. Since the hallmarks of leprosy are nerve enlargement and inflammation, we used high-resolution sonography (US) and color Doppler (CD) imaging to demonstrate nerve enlargement and inflammation. Methology/Principal Findings We performed bilateral US of the ulnar (UN), median (MN), lateral popliteal (LP) and posterior tibial (PT) nerves in 20 leprosy patients and compared this with the clinical findings in these patients and with the sonographic findings in 30 healthy Indian controls. The nerves were significantly thicker in the leprosy patients as compared to healthy controls (p<0.0001 for each nerve). The two patients without nerve enlargements did not have a type 1 or type 2 reaction or signs of neuritis. The kappa for clinical palpation and nerve enlargement by sonography was 0.30 for all examined nerves (0.32 for UN, 0.41 for PN and 0.13 for LP). Increased neural vascularity by CD imaging was present in 39 of 152 examined nerves (26%). Increased vascularity was observed in multiple nerves in 6 of 12 patients with type 1 reaction and in 3 of 4 patients with type 2 reaction. Significant correlation was observed between clinical parameters of grade of thickening, sensory loss and muscle weakness and US abnormalities of nerve echotexture, endoneural flow and cross-sectional area (p<0.001). Conclusions/Significance We conclude that clinical examination of enlarged nerves in leprosy patients is subjective and inaccurate, whereas sonography provides an objective measure of nerve damage by showing increased vascularity, distorted echotexture and enlargement. This damage is sonographically more extensive and includes more nerves than clinically expected. PMID:19668356

  18. Craniofacial abnormalities in Hutchinson-Gilford progeria syndrome.

    PubMed

    Ullrich, N J; Silvera, V M; Campbell, S E; Gordon, L B

    2012-09-01

    HGPS is a rare syndrome of segmental premature aging. Our goal was to expand the scope of structural bone and soft-tissue craniofacial abnormalities in HGPS through CT or MR imaging. Using The Progeria Research Foundation Medical and Research Database, 98 imaging studies on 25 patients, birth to 14.1 years of age, were comprehensively reviewed. Eight newly identified abnormalities involving the calvaria, skull base, and soft tissues of the face and orbits were present with prevalences between 43% and 100%. These included J-shaped sellas, a mottled appearance and increased vascular markings of the calvaria, abnormally configured mandibular condyles, hypoplastic articular eminences, small zygomatic arches, prominent parotid glands, and optic nerve kinking. This expanded craniofacial characterization helps link disease features and improves our ability to evaluate how underlying genetic and cellular abnormalities culminate in a disease phenotype.

  19. Hibernating myocardium results in partial sympathetic denervation and nerve sprouting.

    PubMed

    Fernandez, Stanley F; Ovchinnikov, Vladislav; Canty, John M; Fallavollita, James A

    2013-01-15

    Hibernating myocardium due to chronic repetitive ischemia is associated with regional sympathetic nerve dysfunction and spontaneous arrhythmic death in the absence of infarction. Although inhomogeneity in regional sympathetic innervation is an acknowledged substrate for sudden death, the mechanism(s) responsible for these abnormalities in viable, dysfunctional myocardium (i.e., neural stunning vs. sympathetic denervation) and their association with nerve sprouting are unknown. Accordingly, markers of sympathetic nerve function and nerve sprouting were assessed in subendocardial tissue collected from chronically instrumented pigs with hibernating myocardium (n = 18) as well as sham-instrumented controls (n = 7). Hibernating myocardium exhibited evidence of partial sympathetic denervation compared with the normally perfused region and sham controls, with corresponding regional reductions in tyrosine hydroxylase protein (-32%, P < 0.001), norepinephrine uptake transport protein (-25%, P = 0.01), and tissue norepinephrine content (-45%, P < 0.001). Partial denervation induced nerve sprouting with regional increases in nerve growth factor precursor protein (31%, P = 0.01) and growth associated protein-43 (38%, P < 0.05). All of the changes in sympathetic nerve markers were similar in animals that developed sudden death (n = 9) compared with electively terminated pigs with hibernating myocardium (n = 9). In conclusion, sympathetic nerve dysfunction in hibernating myocardium is most consistent with partial sympathetic denervation and is associated with regional nerve sprouting. The extent of sympathetic remodeling is similar in animals that develop sudden death compared with survivors; this suggests that sympathetic remodeling in hibernating myocardium is not an independent trigger for sudden death. Nevertheless, sympathetic remodeling likely contributes to electrical instability in combination with other factors.

  20. Biological and Electrophysiologic Effects of Poly(3,4-ethylenedioxythiophene) on Regenerating Peripheral Nerve Fibers

    PubMed Central

    Baghmanli, Ziya; Sugg, Kristoffer B.; Wei, Benjamin; Shim, Bong S.; Martin, David C.; Cederna, Paul S.; Urbanchek, Melanie G.

    2014-01-01

    Background Uninjured peripheral nerves in upper-limb amputees represent attractive sites for connectivity with neuroprostheses because their predictable internal topography allows for precise sorting of motor and sensory signals. The inclusion of poly(3,4-ethylenedioxythiophene) reduces impedance and improves charge transfer at the biotic-abiotic interface. This study evaluates the in vivo performance of poly(3,4-ethylenedioxythiophene)–coated interpositional decellularized nerve grafts across a critical nerve conduction gap, and examines the long-term effects of two different poly(3,4-ethylenedioxythiophene) formulations on regenerating peripheral nerve fibers. Methods In 48 rats, a 15-mm gap in the common peroneal nerve was repaired using a nerve graft of equivalent length, including (1) decellularized nerve chemically polymerized with poly(3,4-ethylenedioxythiophene) (dry); (2) decellularized nerve electrochemically polymerized with poly(3,4-ethylenedioxythiophene) (wet); (3) intact nerve; (4) autogenous nerve graft; (5) decellularized nerve alone; and (6) unrepaired nerve gap controls. All groups underwent electrophysiologic characterization at 3 months, and nerves were harvested for histomorphometric analysis. Results Conduction velocity was significantly faster in the dry poly(3,4-ethylenedioxythiophene) group compared with the sham, decellularized nerve, and wet poly(3,4-ethylenedioxythiophene) groups. Maximum specific force for the dry poly(3,4-ethylenedioxythiophene) group was more similar to sham than were decellularized nerve controls. Evident neural regeneration was demonstrated in both dry and wet poly(3,4-ethylenedioxythiophene) groups by the presence of normal regenerating axons on histologic cross-section. Conclusions Both poly(3,4-ethylenedioxythiophene) formulations were compatible with peripheral nerve regeneration at 3 months. This study supports poly(3,4-ethylenedioxythiophene) as a promising adjunct for peripheral nerve interfaces for

  1. A novel electrospun nerve conduit enhanced by carbon nanotubes for peripheral nerve regeneration

    NASA Astrophysics Data System (ADS)

    Yu, Wenwen; Jiang, Xinquan; Cai, Ming; Zhao, Wen; Ye, Dongxia; Zhou, Yong; Zhu, Chao; Zhang, Xiuli; Lu, Xiaofeng; Zhang, Zhiyuan

    2014-04-01

    For artificial nerve conduits, great improvements have been achieved in mimicking the structures and components of autologous nerves. However, there are still some problems in conduit construction, especially in terms of mechanical properties, biomimetic surface tomography, electrical conductivity and sustained release of neurotrophic factors or cells. In this study, we designed and fabricated a novel electrospun nerve conduit enhanced by multi-walled carbon nanotubes (MWNTs) on the basis of a collagen/poly(ɛ-caprolactone) (collagen/PCL) fibrous scaffold. Our aim was to provide further knowledge about the mechanical effects and efficacy of MWNTs on nerve conduits as well as the biocompatibility and toxicology of MWNTs when applied in vivo. The results showed that as one component, carboxyl MWNTs could greatly alter the composite scaffold’s hydrophilicity, mechanical properties and degradability. The electrospun fibers enhanced by MWNTs could support Schwann cell adhesion and elongation as a substrate in vitro. In vivo animal studies demonstrated that the MWNT-enhanced collagen/PCL conduit could effectively promote nerve regeneration of sciatic nerve defect in rats and prevent muscle atrophy without invoking body rejection or serious chronic inflammation. All of these results showed that this MWNT-enhanced scaffold possesses good biocompatibility and MWNTs might be excellent candidates as engineered nanocarriers for further neurotrophic factor delivery research.

  2. Allograft pretreatment for the repair of sciatic nerve defects: green tea polyphenols versus radiation

    PubMed Central

    Zhou, Sheng-hu; Zhen, Ping; Li, Shen-song; Liang, Xiao-yan; Gao, Ming-xuan; Tian, Qi; Li, Xu-sheng

    2015-01-01

    Pretreatment of nerve allografts by exposure to irradiation or green tea polyphenols can eliminate neuroimmunogenicity, inhibit early immunological rejection, encourage nerve regeneration and functional recovery, improve tissue preservation, and minimize postoperative infection. In the present study, we investigate which intervention achieves better results. We produced a 1.0 cm sciatic nerve defect in rats, and divided the rats into four treatment groups: autograft, fresh nerve allograft, green tea polyphenol-pretreated (1 mg/mL, 4°C) nerve allograft, and irradiation-pretreated nerve allograft (26.39 Gy/min for 12 hours; total 19 kGy). The animals were observed, and sciatic nerve electrophysiology, histology, and transmission electron microscopy were carried out at 6 and 12 weeks after grafting. The circumference and structure of the transplanted nerve in rats that received autografts or green tea polyphenol-pretreated nerve allografts were similar to those of the host sciatic nerve. Compared with the groups that received fresh or irradiation-pretreated nerve allografts, motor nerve conduction velocity in the autograft and fresh nerve allograft groups was greater, more neurites grew into the allografts, Schwann cell proliferation was evident, and a large number of new blood vessels was observed; in addition, massive myelinated nerve fibers formed, and abundant microfilaments and microtubules were present in the axoplasm. Our findings indicate that nerve allografts pretreated by green tea polyphenols are equivalent to transplanting autologous nerves in the repair of sciatic nerve defects, and promote nerve regeneration. Pretreatment using green tea polyphenols is better than pretreatment with irradiation. PMID:25788934

  3. Improved Peripheral Nerve Regeneration Using Acellular Nerve Allografts Loaded with Platelet-Rich Plasma

    PubMed Central

    Zheng, Canbin; Huang, Xijun; He, Caifeng; Jiang, Li; Quan, Daping

    2014-01-01

    Acellular nerve allografts (ANAs) behave in a similar manner to autografts in supporting axonal regeneration in the repair of short peripheral nerve defects but fail in larger defects. The objective of this article is to evaluate the effect of ANA supplemented with platelet-rich plasma (PRP) to improve nerve regeneration after surgical repair and to discuss the mechanisms that underlie this approach. Autologous PRP was obtained from rats by double-step centrifugation and was characterized by determining platelet numbers and the release of growth factors. Forty-eight Sprague–Dawley rats were randomly divided into 4 groups (12/group), identified as autograft, ANA, ANA loaded with PRP (ANA+PRP), and ANA loaded with platelet-poor plasma (PPP, ANA+PPP). All grafts were implanted to bridge long-gap (15 mm) sciatic nerve defects. We found that PRP with a high platelet concentration exhibited a sustained release of growth factors. Twelve weeks after surgery, the autograft group displayed the highest level of reinnervation, followed by the ANA+PRP group. The ANA+PRP group showed a better electrophysiology response for amplitude and conduction velocity than the ANA and ANA+PPP groups. Based on histological evaluation, the ANA+PRP and autograft groups had higher numbers of regenerating nerve fibers. Quantitative real-time polymerase chain reaction (qRT-PCR) demonstrated that PRP boosted expression of neurotrophins in the regenerated nerves. Moreover, the ANA+PRP and autograft groups showed excellent physiological outcomes in terms of the prevention of muscle atrophy. In conclusion, ANAs loaded with PRP as tissue-engineered scaffolds can enhance nerve regeneration and functional recovery after the repair of large nerve gaps nearly as well as autografts. PMID:24901030

  4. Relationship Between Optic Nerve Appearance and Retinal Nerve Fiber Layer Thickness as Explored with Spectral Domain Optical Coherence Tomography

    PubMed Central

    Aleman, Tomas S.; Huang, Jiayan; Garrity, Sean T.; Carter, Stuart B.; Aleman, Wendy D.; Ying, Gui-shuang; Tamhankar, Madhura A.

    2014-01-01

    Purpose To study the relationship between the appearance of the optic nerve and the retinal nerve fiber layer (RNFL) thickness determined by spectral domain optical coherence tomography (OCT). Methods Records from patients with spectral domain-OCT imaging in a neuro-ophthalmology practice were reviewed. Eyes with glaucoma/glaucoma suspicion, macular/optic nerve edema, pseudophakia, and with refractive errors > 6D were excluded. Optic nerve appearance by slit lamp biomicroscopy was related to the RNFL thickness by spectral domain-OCT and to visual field results. Results Ninety-one patients (176 eyes; mean age: 49 ± 15 years) were included. Eighty-three eyes (47%) showed optic nerve pallor; 89 eyes (50.6%) showed RNFL thinning (sectoral or average peripapillary). Average peripapillary RNFL thickness in eyes with pallor (mean ± SD = 76 ± 17 μm) was thinner compared to eyes without pallor (91 ± 14 μm, P < 0.001). Optic nerve pallor predicted RNFL thinning with a sensitivity of 69% and a specificity of 75%. Optic nerve appearance predicted RNFL thinning (with a sensitivity and specificity of 81%) when RNFL had thinned by ∼ 40%. Most patients with pallor had RNFL thinning with (66%) or without (25%) visual field loss; the remainder had normal RNFL and fields (5%) or with visual field abnormalities (4%). Conclusions Optic nerve pallor as a predictor of RNFL thinning showed fair sensitivity and specificity, although it is optimally sensitive/specific only when substantial RNFL loss has occurred. Translational Relevance Finding an acceptable relationship between the optic nerve appearance by ophthalmoscopy and spectral domain-OCT RNFL measures will help the clinician's interpretation of the information provided by this technology, which is gaining momentum in neuro-ophthalmic research. PMID:25374773

  5. [Hair shaft abnormalities].

    PubMed

    Itin, P H; Düggelin, M

    2002-05-01

    Hair shaft disorders may lead to brittleness and uncombable hair. In general the hair feels dry and lusterless. Hair shaft abnormalities may occur as localized or generalized disorders. Genetic predisposition or exogenous factors are able to produce and maintain hair shaft abnormalities. In addition to an extensive history and physical examination the most important diagnostic examination to analyze a hair shaft problem is light microscopy. Therapy of hair shaft disorders should focus to the cause. In addition, minimizing traumatic influences to hair shafts, such as dry hair with an electric dryer, permanent waves and dyes is important. A short hair style is more suitable for such patients with hair shaft disorders.

  6. Malignant granular cell tumor of the lateral femoral cutaneous nerve: report of a case with cytogenetic analysis.

    PubMed

    Di Tommaso, Luca; Magrini, Elisabetta; Consales, Alessandro; Poppi, Massimo; Pasquinelli, Gianandrea; Dorji, Tsering; Benedetti, Giovanni; Baccarini, Paola

    2002-12-01

    Malignant granular cell tumors (MGCTs) are rare neoplasms of uncertain histogenesis. We report a case of MGCT involving a peripheral nerve with peritoneal and omental dissemination in which cytogenetic findings are available. Our results show that MGCTs share some cytogenetic abnormalities with malignant peripheral nerve sheath tumors (MPNSTs), supporting the hypothesis that they may represent histogenetically related lesions.

  7. Peripheral nerve response to injury.

    PubMed

    Steed, Martin B

    2011-03-01

    Oral and maxillofacial surgeons caring for patients who have sustained a nerve injury to a branch of the peripheral trigeminal nerve must possess a basic understanding of the response of the peripheral nerves to trauma. The series of events that subsequently take place are largely dependent on the injury type and severity. Regeneration of the peripheral nerve is possible in many instances and future manipulation of the regenerative microenvironment will lead to advances in the management of these difficult injuries.

  8. Effect of a new aldose reductase inhibitor, 8'-chloro-2',3'-dihydrospiro [pyrrolidine-3,6'(5'H)-pyrrolo[1,2,3-de] [1,4]benzoxazine]-2,5,5'- trione (ADN-138), on delayed motor nerve conduction velocity in streptozotocin-diabetic rats.

    PubMed

    Hirata, Y; Fujimori, S; Okada, K

    1988-02-01

    The effects of a chemically new type of aldose reductase inhibitor, ADN-138, on delayed motor nerve conduction velocity (MNCV) and sciatic nerve sorbitol, fructose and myo-inositol levels were studied in streptozotocin-diabetic rats. MNCV in rats was significantly delayed after 3 weeks of diabetes and ADN-138 treatment was started at this point. Treatment of diabetics with ADN-138 at 5 and 20 but not 1 mg/kg/d for 3 weeks resulted in a significant increase in MNCV and reduced sorbitol levels to or below those of nondiabetic controls. However, fructose, though decreased in a dose-dependent manner, was not normalized. The reference drug, Sorbinil, showed similar effects on them. After the 3 weeks of ADN-138(20 mg/kg/d) treatment, diabetics were left on ADN-138 or continued further to be treated with it for 3 weeks. The withdrawal of ADN-138 prevented a further increase in MNCV and restored sorbitol and fructose to nontreated diabetic levels, and myo-inositol levels declined. In contrast, the ADN-138-continued group kept improving its MNCV and normalized sorbitol and myo-inositol. These results suggest that polyol accumulation is responsible for delayed MNCV and that the action of ADN-138 on MNCV reflected reversibility of metabolic function in diabetics.

  9. Ischemic Nerve Block.

    ERIC Educational Resources Information Center

    Williams, Ian D.

    This experiment investigated the capability for movement and muscle spindle function at successive stages during the development of ischemic nerve block (INB) by pressure cuff. Two male subjects were observed under six randomly ordered conditions. The duration of index finger oscillation to exhaustion, paced at 1.2Hz., was observed on separate…

  10. Optic Nerve Atrophy

    MedlinePlus

    ... with the occipital lobe (the part of the brain that interprets vision) like a cable wire. What is optic nerve ... nystagmus. In older patients, peripheral vision and color vision assessment ... around the brain and spinal cord (hydrocephalus) may prevent further optic ...

  11. Exploring vocal recovery after cranial nerve injury in Bengalese finches.

    PubMed

    Urbano, Catherine M; Peterson, Jennifer R; Cooper, Brenton G

    2013-02-01

    Songbirds and humans use auditory feedback to acquire and maintain their vocalizations. The Bengalese finch (Lonchura striata domestica) is a songbird species that rapidly modifies its vocal output to adhere to an internal song memory. In this species, the left side of the bipartite vocal organ is specialized for producing louder, higher frequencies (≥2.2kHz) and denervation of the left vocal muscles eliminates these notes. Thus, the return of higher frequency notes after cranial nerve injury can be used as a measure of vocal recovery. Either the left or right side of the syrinx was denervated by resection of the tracheosyringeal portion of the hypoglossal nerve. Histologic analyses of syringeal muscle tissue showed significant muscle atrophy in the denervated side. After left nerve resection, songs were mainly composed of lower frequency syllables, but three out of five birds recovered higher frequency syllables. Right nerve resection minimally affected phonology, but it did change song syntax; syllable sequence became abnormally stereotyped after right nerve resection. Therefore, damage to the neuromuscular control of sound production resulted in reduced motor variability, and Bengalese finches are a potential model for functional vocal recovery following cranial nerve injury.

  12. Biomechanical and functional variation in rat sciatic nerve following cuff electrode implantation

    PubMed Central

    2014-01-01

    Background Nerve cuff electrodes are commonly and successfully used for stimulating peripheral nerves. On the other hand, they occasionally induce functional and morphological changes following chronic implantation, for reasons not always clear. We hypothesize that restriction of nerve mobility due to cuff implantation may alter nerve conduction. Methods We quantified acute changes in nerve-muscle electrophysiology, using electromyography, and nerve kinematics in anesthetized Sprague Dawley rat sciatic nerves during controlled hindlimb joint movement. We compared electrophysiological and biomechanical response in uncuffed nerves and those secured within a cuff electrode using analysis of variance (ANOVA) and regression analysis. Results Tethering resulting from cuff implantation resulted in altered nerve strain and a complex biomechanical environment during joint movement. Coincident with biomechanical changes, electromyography revealed significantly increased variability in the response of conduction latency and amplitude in cuffed, but not free, nerves following joint movement. Conclusion Our findings emphasize the importance of the mechanical interface between peripheral nerves and their devices on neurophysiological performance. This work has implications for nerve device design, implantation, and prediction of long-term efficacy. PMID:24758405

  13. Agmatine treatment and vein graft reconstruction enhance recovery after experimental facial nerve injury.

    PubMed

    Berenholz, Leonard; Segal, Shmuel; Gilad, Varda H; Klein, Collen; Yehezkeli, Eyal; Eviatar, Ephraim; Kessler, Alex; Gilad, Gad M

    2005-09-01

    The rate of nerve regeneration is a critical determinant of the degree of functional recovery after injury. Here, we sought to determine whether treatment with the neuroprotective compound, agmatine, with or without nerve reconstruction utilizing a regional autogenous vein graft would accelerate the rate of facial nerve regeneration. Experiments compared the following seven groups of adult male rats: (A) Intact untreated controls. (B) Sham operation with interruption of the nerve blood supply (controls). (C) Transection of the mandibular branch of the facial nerve (generating a gap of 3 mm) followed by saline treatment. (D) Nerve transection with unsutured autogenous vein (external jugular) graft reconstruction plus saline treatment. (E) Nerve transection with sutured vein graft approximation (coaptation of the proximal and distal nerve stumps) plus saline. (F) Nerve transection with sutured vein graft followed by agmatine treatment (four daily intraperitoneal injections of 100 mg/kg agmatine sulfate). (G) Nerve transection with unsutured vein graft followed by agmatine treatment. Functional recovery, as assessed by grading vibrissae movements and by recording nerve conduction velocity and numbers of regenerated axons, indicated that either vein reconstruction or agmatine treatment resulted in accelerated and more complete recovery as compared with controls. But best results were observed in animals that underwent combined treatment, i.e., vein reconstruction plus agmatine injection. We conclude that agmatine treatment can accelerate facial nerve regeneration and that agmatine treatment together with autogenous vein graft offers an advantageous alternative to other facial nerve reconstruction procedures.

  14. Nerve Bundles and Deep Dyspareunia in Endometriosis.

    PubMed

    Williams, Christina; Hoang, Lien; Yosef, Ali; Alotaibi, Fahad; Allaire, Catherine; Brotto, Lori; Fraser, Ian S; Bedaiwy, Mohamed A; Ng, Tony L; Lee, Anna F; Yong, Paul J

    2016-07-01

    The etiology of deep dyspareunia in endometriosis is unclear. Our objective was to determine whether nerve bundle density in the cul-de-sac/uterosacrals (zone II) is associated with deep dyspareunia in women with endometriosis. We conducted a blinded retrospective immunohistochemistry study (n = 58) at a tertiary referral center (2011-2013). Patients were stringently phenotyped into a study group and 2 control groups. The study group (tender endometriosis, n = 29) consisted of patients with deep dyspareunia, a tender zone II on examination, and an endometriosis lesion in zone II excised at surgery. Control group 1 (nontender endometriosis, n = 17) consisted of patients without deep dyspareunia, a nontender zone II on examination, and an endometriosis lesion in zone II excised at surgery. Control group 2 (tender nonendometriosis, n = 12) consisted of patients with deep dyspareunia, a tender zone II on examination, and a nonendometriosis lesion (eg, normal histology) in zone II excised at surgery. Protein gene product 9.5 (PGP9.5) immunohistochemistry was performed to identify nerve bundles (nerve fibers surrounded by perineurium) in the excised zone II lesion. PGP9.5 nerve bundle density (bundles/high powered field [HPF]) was then scored by a pathologist blinded to the group. We found a significant difference in PGP9.5 nerve bundle density between the 3 groups (analysis of variance, F2,55 = 6.39, P = .003). Mean PGP9.5 nerve bundle density was significantly higher in the study group (1.16 ± 0.56 bundles/HPF [±standard deviation]) compared to control group 1 (0.65 ± 0.36, Tukey test, P = .005) and control group 2 (0.72 ± 0.56, Tukey test, P = .044). This study provides evidence that neurogenesis in the cul-de-sac/uterosacrals may be an etiological factor for deep dyspareunia in endometriosis.

  15. Low serum magnesium levels are associated with impaired peripheral nerve function in type 2 diabetic patients

    PubMed Central

    Chu, Chen; Zhao, Weijing; Zhang, Yinan; Li, Lu; Lu, Jingyi; Jiang, Lan; Wang, Congrong; Jia, Weiping

    2016-01-01

    The aim of this study was to explore the relationship between serum magnesium and peripheral nerve function in patients with type 2 diabetes (T2DM). A total of 978 T2DM patients were included in the study. Patients were divided into tertiles according to serum magnesium concentration (low tertile: ≤0.85 mmol/L; medium tertile: 0.85 to 0.92 mmol/L; and high tertile: >0.92 mmol/L). All participants underwent nerve conduction (NC) studies. Composite z scores of conduction velocity, latency, and amplitude were constructed, respectively. The serum magnesium levels were significantly lower in patients with abnormal NC than in those with normal NC (0.87 [0.82, 0.92] vs. 0.88 [0.83, 0.93] mmol/L, P = 0.048). The composite z score of amplitude significantly increased with increasing tertiles of magnesium (−0.60 ± 0.02 vs. −0.57 ± 0.02 vs. −0.48 ± 0.03, P for trend = 0.001). After adjusting for all potential confounders, lower serum magnesium levels were still associated with lower composite z score of amplitude (β = 0.095, P = 0.014). In patients with T2DM, lower serum magnesium levels were significantly associated with lower composite z score of amplitude, indicating magnesium might affect peripheral nerve function through axonal degeneration. PMID:27601013

  16. Low serum magnesium levels are associated with impaired peripheral nerve function in type 2 diabetic patients.

    PubMed

    Chu, Chen; Zhao, Weijing; Zhang, Yinan; Li, Lu; Lu, Jingyi; Jiang, Lan; Wang, Congrong; Jia, Weiping

    2016-01-01

    The aim of this study was to explore the relationship between serum magnesium and peripheral nerve function in patients with type 2 diabetes (T2DM). A total of 978 T2DM patients were included in the study. Patients were divided into tertiles according to serum magnesium concentration (low tertile: ≤0.85 mmol/L; medium tertile: 0.85 to 0.92 mmol/L; and high tertile: >0.92 mmol/L). All participants underwent nerve conduction (NC) studies. Composite z scores of conduction velocity, latency, and amplitude were constructed, respectively. The serum magnesium levels were significantly lower in patients with abnormal NC than in those with normal NC (0.87 [0.82, 0.92] vs. 0.88 [0.83, 0.93] mmol/L, P = 0.048). The composite z score of amplitude significantly increased with increasing tertiles of magnesium (-0.60 ± 0.02 vs. -0.57 ± 0.02 vs. -0.48 ± 0.03, P for trend = 0.001). After adjusting for all potential confounders, lower serum magnesium levels were still associated with lower composite z score of amplitude (β = 0.095, P = 0.014). In patients with T2DM, lower serum magnesium levels were significantly associated with lower composite z score of amplitude, indicating magnesium might affect peripheral nerve function through axonal degeneration. PMID:27601013

  17. Laser-activated protein solder for peripheral nerve repair

    NASA Astrophysics Data System (ADS)

    Trickett, Rodney I.; Lauto, Antonio; Dawes, Judith M.; Owen, Earl R.

    1995-05-01

    A 100 micrometers core optical fiber-coupled 75 mW diode laser operating at a wavelength of 800 nm has been used in conjunction with a protein solder to stripe weld severed rat tibial nerves, reducing the long operating time required for microsurgical nerve repair. Welding is produced by selective laser denaturation of the albumin based solder which contains the dye indocyanine green. Operating time for laser soldering was 10 +/- 5 min. (n equals 20) compared to 23 +/- 9 min. (n equals 10) for microsuturing. The laser solder technique resulted in patent welds with a tensile strength of 15 +/- 5 g, while microsutured nerves had a tensile strength of 40 +/- 10 g. Histopathology of the laser soldered nerves, conducted immediately after surgery, displayed solder adhesion to the outer membrane with minimal damage to the inner axons of the nerves. An in vivo study is under way comparing laser solder repaired tibial nerves to conventional microsuture repair. At the time of submission 15 laser soldered nerves and 7 sutured nerves were characterized at 3 months and showed successful regeneration with compound muscle action potentials of 27 +/- 8 mV and 29 +/- 8 mW respectively. A faster, less damaging and long lasting laser based anastomotic technique is presented.

  18. Involvement of Peripheral Nerves in the Transgenic PLP-α-Syn Model of Multiple System Atrophy: Extending the Phenotype

    PubMed Central

    Kuzdas-Wood, Daniela; Irschick, Regina; Theurl, Markus; Malsch, Philipp; Mair, Norbert; Mantinger, Christine; Wanschitz, Julia; Klimaschewski, Lars; Poewe, Werner; Stefanova, Nadia; Wenning, Gregor K.

    2015-01-01

    Multiple system atrophy (MSA) is a fatal, rapidly progressive neurodegenerative disease with (oligodendro-)glial cytoplasmic α-synuclein (α-syn) inclusions (GCIs). Peripheral neuropathies have been reported in up to 40% of MSA patients, the cause remaining unclear. In a transgenic MSA mouse model featuring GCI-like inclusion pathology based on PLP-promoter driven overexpression of human α-syn in oligodendroglia motor and non-motor deficits are associated with MSA-like neurodegeneration. Since α-syn is also expressed in Schwann cells we aimed to investigate whether peripheral nerves are anatomically and functionally affected in the PLP-α-syn MSA mouse model. Results To this end, heat/cold as well as mechanical sensitivity tests were performed. Furthermore, in vivo and ex vivo nerve conduction and the G-ratios of the sciatic nerve were analyzed, and thermosensitive ion channel mRNA expression in dorsal root ganglia (DRG) was assessed. The presence of human α-syn in Schwann cells was associated with subtle behavioral impairments. The G-ratio of the sciatic nerve, the conduction velocity of myelinated and unmyelinated primary afferents and the expression of thermosensitive ion channels in the sensory neurons, however, were similar to wildtype mice. Conclusion Our results suggest that the PNS appears to be affected by Schwann cell α-syn deposits in the PLP-α-syn MSA mouse model. However, there was no consistent evidence for functional PNS perturbations resulting from such α-syn aggregates suggesting a more central cause of the observed behavioral abnormalities. Nonetheless, our results do not exclude a causal role of α-syn in the pathogenesis of MSA associated peripheral neuropathy. PMID:26496712

  19. Autonomic correlations with MRI are abnormal in the brainstem vasomotor centre in Chronic Fatigue Syndrome

    PubMed Central

    Barnden, Leighton R.; Kwiatek, Richard; Crouch, Benjamin; Burnet, Richard; Del Fante, Peter

    2016-01-01

    Autonomic changes are often associated with the chronic fatigue syndrome (CFS), but their pathogenetic role is unclear and brain imaging investigations are lacking. The vasomotor centre and, through it, nuclei in the midbrain and hypothalamus play a key role in autonomic nervous system regulation of steady state blood pressure (BP) and heart rate (HR). In this exploratory cross-sectional study, BP and HR, as indicators of autonomic function, were correlated with volumetric and T1- and T2-weighted spin-echo (T1w and T2w) brain MRI in 25 CFS subjects and 25 normal controls (NC). Steady state BP (systolic, diastolic and pulse pressure) and HR in two postures were extracted from 24 h blood pressure monitoring. We performed (1) MRI versus autonomic score interaction-with-group regressions to detect locations where regression slopes differed in the CFS and NC groups (collectively indicating abnormality in CFS), and (2) MRI regressions in the CFS and NC groups alone to detect additional locations with abnormal correlations in CFS. Significant CFS regressions were repeated controlling for anxiety and depression (A&D). Abnormal regressions were detected in nuclei of the brainstem vasomotor centre, midbrain reticular formation and hypothalamus, but also in limbic nuclei involved in stress responses and in prefrontal white matter. Group comparisons of CFS and NC did not find MRI differences in these locations. We propose therefore that these regulatory nuclei are functioning correctly, but that two-way communication between them is impaired in CFS and this affects signalling to/from peripheral effectors/sensors, culminating in inverted or magnified correlations. This single explanation for the diverse abnormal correlations detected here consolidates the conclusion for a brainstem/midbrain nerve conduction deficit inferred earlier (Barnden et al., 2015). Strong correlations were also detected in isolated NC regressions. PMID:27114901

  20. Propagation and spatiotemporal summation of electrical pulses in semiconductor nerve fibers

    NASA Astrophysics Data System (ADS)

    Samardak, A.; Taylor, S.; Nogaret, A.; Hollier, G.; Austin, J.; Ritchie, D. A.

    2007-08-01

    The authors report the propagation and analog summation of electrical impulses in artificial nerve fibers made of submicron p-n wires. These wires model the longitudinal conductivities of K + and Na+ ions inside and outside a nerve capillary as well as the transverse capacitance of the nerve membrane and the nonlinear conductance of its ion channels. They demonstrate the summation and annihilation of electrical impulses at room temperature which form the basis for making spike timing neural networks.

  1. Focused ultrasound effects on nerve action potential in vitro

    PubMed Central

    Colucci, Vincent; Strichartz, Gary; Jolesz, Ferenc; Vykhodtseva, Natalia; Hynynen, Kullervo

    2009-01-01

    Minimally invasive applications of thermal and mechanical energy to selective areas of the human anatomy have led to significant advances in treatment of and recovery from typical surgical interventions. Image-guided focused ultrasound allows energy to be deposited deep into the tissue, completely noninvasively. There has long been interest in using this focal energy delivery to block nerve conduction for pain control and local anesthesia. In this study, we have performed an in vitro study to further extend our knowledge of this potential clinical application. The sciatic nerves from the bullfrog (Rana catesbeiana) were subjected to focused ultrasound (at frequencies of 0.661MHz and 1.986MHz) and to heated Ringer’s solution. The nerve action potential was shown to decrease in the experiments and correlated with temperature elevation measured in the nerve. The action potential recovered either completely, partially, or not at all, depending on the parameters of the ultrasound exposure. The reduction of the baseline nerve temperature by circulating cooling fluid through the sonication chamber did not prevent the collapse of the nerve action potential; but higher power was required to induce the same endpoint as without cooling. These results indicate that a thermal mechanism of focused ultrasound can be used to block nerve conduction, either temporarily or permanently. PMID:19647923

  2. Recurrent largngeal nerve paralysis: a laryngographic and computed tomographic study

    SciTech Connect

    Agha, F.P.

    1983-07-01

    Vocal cord paralysis is a relatively common entity, usually resulting from a pathologic process of the vagus nerve or its recurrent larynegeal branch. It is rarely caused by intralargngeal lesions. Four teen patients with recurrent laryngeal nerve paralysis (RLNP) were evaluated by laryngography, computed tomography (CT), or both. In the evaluation of the paramedian cord, CT was limited in its ability to differentiate between tumor or RLNP as the cause of the fixed cord, but it yielded more information than laryngography on the structural abnormalities of the larynx and pre-epiglottic and paralaryngeal spaces. Laryngography revealed distinct features of RLNP and is the procedure of choice for evaluation of functional abnormalities of the larynx until further experience with faster CT scanners and dynamic scanning of the larynx is gained.

  3. Musculocutaneous nerve injury in a high school pitcher.

    PubMed

    Stephens, Luke; Kinderknecht, James J; Wen, Dennis Y

    2014-11-01

    : Nontraumatic musculocutaneous nerve palsy is a rare injury that can occur in throwers. We present a case of musculocutaneous nerve injury in a high school pitcher, which has rarely been previously reported. The unique electromyography findings add to the overall spectrum seen with musculocutaneous nerve injuries in throwers. Sensory abnormalities may not be present at initial evaluation, but rather weakness or pain of the biceps is the most common presenting concern. Electrodiagnostic evaluation is paramount for confirmation of diagnosis, yet the timing of this study is critical for its accuracy. Rest and progressive physical therapy remain as the current treatment of choice. Resolution of symptoms, although time consuming, is complete in the majority of cases, including ours.

  4. Sciatic nerve repair with tissue engineered nerve: Olfactory ensheathing cells seeded poly(lactic-co-glygolic acid) conduit in an animal model

    PubMed Central

    Tan, C W; Ng, M H; Ohnmar, H; Lokanathan, Y; Nur-Hidayah, H; Roohi, S A; Ruszymah, BHI; Nor-Hazla, M H; Shalimar, A; Naicker, A S

    2013-01-01

    Background and Aim: Synthetic nerve conduits have been sought for repair of nerve defects as the autologous nerve grafts causes donor site morbidity and possess other drawbacks. Many strategies have been investigated to improve nerve regeneration through synthetic nerve guided conduits. Olfactory ensheathing cells (OECs) that share both Schwann cell and astrocytic characteristics have been shown to promote axonal regeneration after transplantation. The present study was driven by the hypothesis that tissue-engineered poly(lactic-co-glycolic acid) (PLGA) seeded with OECs would improve peripheral nerve regeneration in a long sciatic nerve defect. Materials and Methods: Sciatic nerve gap of 15 mm was created in six adult female Sprague-Dawley rats and implanted with PLGA seeded with OECs. The nerve regeneration was assessed electrophysiologically at 2, 4 and 6 weeks following implantation. Histopathological examination, scanning electron microscopic (SEM) examination and immunohistochemical analysis were performed at the end of the study. Results: Nerve conduction studies revealed a significant improvement of nerve conduction velocities whereby the mean nerve conduction velocity increases from 4.2 ΁ 0.4 m/s at week 2 to 27.3 ΁ 5.7 m/s at week 6 post-implantation (P < 0.0001). Histological analysis revealed presence of spindle-shaped cells. Immunohistochemical analysis further demonstrated the expression of S100 protein in both cell nucleus and the cytoplasm in these cells, hence confirming their Schwann-cell-like property. Under SEM, these cells were found to be actively secreting extracellular matrix. Conclusion: Tissue-engineered PLGA conduit seeded with OECs provided a permissive environment to facilitate nerve regeneration in a small animal model. PMID:24379458

  5. Radial nerve palsy: a complication of walker usage.

    PubMed

    Ball, N A; Stempien, L M; Pasupuleti, D V; Wertsch, J J

    1989-03-01

    A patient with diabetic peripheral neuropathy experienced the acute onset of a proximal radial nerve palsy after prolonged use of a walker. Nerve conduction and electromyographic studies confirmed an isolated, severe neurapraxic lesion distal to branches innervating the triceps and anconeus muscles. The acute onset and severity of this lesion suggests that it was caused by mechanical compression of the radial nerve as it exits the spiral groove. Radial mononeuropathy has been reported in conjunction with muscular effort of the triceps muscle. Previous case studies and a review of the literature are discussed. Awareness of this complication in patients using walkers and wheelchairs is important for prevention and diagnosis in rehabilitation.

  6. Myofibroma in the Palm Presenting with Median Nerve Compression Symptoms

    PubMed Central

    Sarkozy, Heidi

    2014-01-01

    Summary: A myofibroma is a benign proliferation of myofibroblasts in the connective tissue. Solitary myofibromas are a rare finding especially in an adult. We report a case of a 23-year-old man presenting with an enlarging mass over his right palm. The patient is an active weight lifter. He reported numbness and tingling in the median nerve distribution. Nerve conduction studies and magnetic resonance imaging scans suggested a tumor involving or compressing the median nerve. The final diagnosis of myofibroma was made only after the histopathological diagnosis. PMID:25426387

  7. Morphological abnormalities in elasmobranchs.

    PubMed

    Moore, A B M

    2015-08-01

    A total of 10 abnormal free-swimming (i.e., post-birth) elasmobranchs are reported from The (Persian-Arabian) Gulf, encompassing five species and including deformed heads, snouts, caudal fins and claspers. The complete absence of pelvic fins in a milk shark Rhizoprionodon acutus may be the first record in any elasmobranch. Possible causes, including the extreme environmental conditions and the high level of anthropogenic pollution particular to The Gulf, are briefly discussed.

  8. Ultrasound of Peripheral Nerves

    PubMed Central

    Suk, Jung Im; Walker, Francis O.; Cartwright, Michael S.

    2013-01-01

    Over the last decade, neuromuscular ultrasound has emerged as a useful tool for the diagnosis of peripheral nerve disorders. This article reviews sonographic findings of normal nerves including key quantitative ultrasound measurements that are helpful in the evaluation of focal and possibly generalized peripheral neuropathies. It also discusses several recent papers outlining the evidence base for the use of this technology, as well as new findings in compressive, traumatic, and generalized neuropathies. Ultrasound is well suited for use in electrodiagnostic laboratories where physicians, experienced in both the clinical evaluation of patients and the application of hands-on technology, can integrate findings from the patient’s history, physical examination, electrophysiological studies, and imaging for diagnosis and management. PMID:23314937

  9. Chromosome abnormalities in glioma

    SciTech Connect

    Li, Y.S.; Ramsay, D.A.; Fan, Y.S.

    1994-09-01

    Cytogenetic studies were performed in 25 patients with gliomas. An interesting finding was a seemingly identical abnormality, an extra band on the tip of the short arm of chromosome 1, add(1)(p36), in two cases. The abnormality was present in all cells from a patient with a glioblastoma and in 27% of the tumor cells from a patient with a recurrent irradiated anaplastic astrocytoma; in the latter case, 7 unrelated abnormal clones were identified except 4 of those clones shared a common change, -Y. Three similar cases have been described previously. In a patient with pleomorphic astrocytoma, the band 1q42 in both homologues of chromosome 1 was involved in two different rearrangements. A review of the literature revealed that deletion of the long arm of chromosome 1 including 1q42 often occurs in glioma. This may indicate a possible tumor suppressor gene in this region. Cytogenetic follow-up studies were carried out in two patients and emergence of unrelated clones were noted in both. A total of 124 clonal breakpoints were identified in the 25 patients. The breakpoints which occurred three times or more were: 1p36, 1p22, 1q21, 1q25, 3q21, 7q32, 8q22, 9q22, 16q22, and 22q13.

  10. [Congenital foot abnormalities].

    PubMed

    Delpont, M; Lafosse, T; Bachy, M; Mary, P; Alves, A; Vialle, R

    2015-03-01

    The foot may be the site of birth defects. These abnormalities are sometimes suspected prenatally. Final diagnosis depends on clinical examination at birth. These deformations can be simple malpositions: metatarsus adductus, talipes calcaneovalgus and pes supinatus. The prognosis is excellent spontaneously or with a simple orthopedic treatment. Surgery remains outstanding. The use of a pediatric orthopedist will be considered if malposition does not relax after several weeks. Malformations (clubfoot, vertical talus and skew foot) require specialized care early. Clubfoot is characterized by an equine and varus hindfoot, an adducted and supine forefoot, not reducible. Vertical talus combines equine hindfoot and dorsiflexion of the forefoot, which is performed in the midfoot instead of the ankle. Skew foot is suspected when a metatarsus adductus is resistant to conservative treatment. Early treatment is primarily orthopedic at birth. Surgical treatment begins to be considered after walking age. Keep in mind that an abnormality of the foot may be associated with other conditions: malposition with congenital hip, malformations with syndromes, neurological and genetic abnormalities. PMID:25524290

  11. Cranial Nerve II: Vision.

    PubMed

    Gillig, Paulette Marie; Sanders, Richard D

    2009-09-01

    This article contains a brief review of the anatomy of the visual system, a survey of diseases of the retina, optic nerve and lesions of the optic chiasm, and other visual field defects of special interest to the psychiatrist. It also includes a presentation of the corticothalamic mechanisms, differential diagnosis, and various manifestations of visual illusions, and simple and complex visual hallucinations, as well as the differential diagnoses of these various visual phenomena. PMID:19855858

  12. Abnormal pressures as hydrodynamic phenomena

    USGS Publications Warehouse

    Neuzil, C.E.

    1995-01-01

    So-called abnormal pressures, subsurface fluid pressures significantly higher or lower than hydrostatic, have excited speculation about their origin since subsurface exploration first encountered them. Two distinct conceptual models for abnormal pressures have gained currency among earth scientists. The static model sees abnormal pressures generally as relict features preserved by a virtual absence of fluid flow over geologic time. The hydrodynamic model instead envisions abnormal pressures as phenomena in which flow usually plays an important role. This paper develops the theoretical framework for abnormal pressures as hydrodynamic phenomena, shows that it explains the manifold occurrences of abnormal pressures, and examines the implications of this approach. -from Author

  13. Generalised peripheral nerve dysfunction in acromegaly: a study by conventional and novel neurophysiological techniques.

    PubMed

    Jamal, G A; Kerr, D J; McLellan, A R; Weir, A I; Davies, D L

    1987-07-01

    Twenty four patients with clinical, radiological and biochemical evidence of acromegaly were investigated by a number of independent neurophysiological tests. Two-thirds of the patients showed evidence of generalised peripheral nerve dysfunction. A significant correlation was found between total exchangeable body sodium, an indicator of disease activity, and the severity of the neuropathy. The generalised peripheral nerve abnormality was found to occur independently of the associated carbohydrate intolerance human growth hormone levels and other endocrinological dysfunction in this disorder.

  14. Sciatic nerve injury related to hip replacement surgery: imaging detection by MR neurography despite susceptibility artifacts.

    PubMed

    Wolf, Marcel; Bäumer, Philipp; Pedro, Maria; Dombert, Thomas; Staub, Frank; Heiland, Sabine; Bendszus, Martin; Pham, Mirko

    2014-01-01

    Sciatic nerve palsy related to hip replacement surgery (HRS) is among the most common causes of sciatic neuropathies. The sciatic nerve may be injured by various different periprocedural mechanisms. The precise localization and extension of the nerve lesion, the determination of nerve continuity, lesion severity, and fascicular lesion distribution are essential for assessing the potential of spontaneous recovery and thereby avoiding delayed or inappropriate therapy. Adequate therapy is in many cases limited to conservative management, but in certain cases early surgical exploration and release of the nerve is indicated. Nerve-conduction-studies and electromyography are essential in the diagnosis of nerve injuries. In postsurgical nerve injuries, additional diagnostic imaging is important as well, in particular to detect or rule out direct mechanical compromise. Especially in the presence of metallic implants, commonly applied diagnostic imaging tests generally fail to adequately visualize nervous tissue. MRI has been deemed problematic due to implant-related artifacts after HRS. In this study, we describe for the first time the spectrum of imaging findings of Magnetic Resonance neurography (MRN) employing pulse sequences relatively insensitive to susceptibility artifacts (susceptibility insensitive MRN, siMRN) in a series of 9 patients with HRS procedure related sciatic nerve palsy. We were able to determine the localization and fascicular distribution of the sciatic nerve lesion in all 9 patients, which clearly showed on imaging predominant involvement of the peroneal more than the tibial division of the sciatic nerve. In 2 patients siMRN revealed direct mechanical compromise of the nerve by surgical material, and in one of these cases indication for surgical release of the sciatic nerve was based on siMRN. Thus, in selected cases of HRS related neuropathies, especially when surgical exploration of the nerve is considered, siMRN, with its potential to largely

  15. Feeling Abnormal: Simulation of Deviancy in Abnormal and Exceptionality Courses.

    ERIC Educational Resources Information Center

    Fernald, Charles D.

    1980-01-01

    Describes activity in which student in abnormal psychology and psychology of exceptional children classes personally experience being judged abnormal. The experience allows the students to remember relevant research, become sensitized to the feelings of individuals classified as deviant, and use caution in classifying individuals as abnormal.…

  16. [Electrical nerve stimulation for plexus and nerve blocks].

    PubMed

    Birnbaum, J; Klotz, E; Bogusch, G; Volk, T

    2007-11-01

    Despite the increasing use of ultrasound, electrical nerve stimulation is commonly used as the standard for both plexus and peripheral nerve blocks. Several recent randomized trials have contributed to a better understanding of physiological and clinical correlations. Traditionally used currents and impulse widths are better defined in relation to the distance between needle tip and nerves. Commercially available devices enable transcutaneous nerve stimulation and provide new opportunities for the detection of puncture sites and for training. The electrically ideal position of the needle usually is defined by motor responses which can not be interpreted without profound anatomical knowledge. For instance, interscalene blocks can be successful even after motor responses of deltoid or pectoral muscles. Infraclavicular blocks should be aimed at stimulation of the posterior fascicle (extension). In contrast to multiple single nerve blocks, axillary single-shot blocks more commonly result in incomplete anaesthesia. Blockade of the femoral nerve can be performed without any nerve stimulation if the fascia iliaca block is used. Independently of the various approaches to the sciatic nerve, inversion and plantar flexion are the best options for single-shot blocks. Further clinical trials are needed to define the advantages of stimulating catheters in continuous nerve blocks.

  17. Nerves and nerve endings in the skin of tropical cattle.

    PubMed

    Amakiri, S F; Ozoya, S E; Ogunnaike, P O

    1978-01-01

    The nerves and nerve endings in the skin of tropical cattle were studied using histological and histochemical techniques. Many nerve trunks and fibres were present in the reticular and papillary dermis in both hairy and non-hairy skin sites. In non-hairy skin locations such as the muzzle and lower lip, encapsulated endings akin to Krause and Ruffini end bulbs, which arise from myelinated nerve trunks situated lower down the dermis were observed at the upper papillary layer level. Some fibre trunks seen at this level extended upwards to terminate within dermal papillae as bulb-shaped longitudinally lamellated Pacinian-type endings, while other onion-shaped lamellated nerve structures were located either within dermal papillae or near the dermo-epidermal area. Intraepidermal free-ending nerve fibres, appearing non-myelinated were observed in areas with thick epidermis. Intraepidermal free-ending nerve fibres, appearing non-myelinated were observed in areas with thick epidermis. On hairy skin sites, however, organized nerve endings or intraepidermal nerve endings were not readily identifiable. PMID:76410

  18. Abnormal human sex chromosome constitutions

    SciTech Connect

    1993-12-31

    Chapter 22, discusses abnormal human sex chromosome constitution. Aneuploidy of X chromosomes with a female phenotype, sex chromosome aneuploidy with a male phenotype, and various abnormalities in X chromosome behavior are described. 31 refs., 2 figs.

  19. Exercises to Improve Gait Abnormalities

    MedlinePlus

    ... Home About iChip Articles Directories Videos Resources Contact Exercises to Improve Gait Abnormalities Home » Article Categories » Exercise and Fitness Font Size: A A A A Exercises to Improve Gait Abnormalities Next Page The manner ...

  20. Abnormal ionization in sonoluminescence

    NASA Astrophysics Data System (ADS)

    Zhang, Wen-Juan; An, Yu

    2015-04-01

    Sonoluminescence is a complex phenomenon, the mechanism of which remains unclear. The present study reveals that an abnormal ionization process is likely to be present in the sonoluminescing bubble. To fit the experimental data of previous studies, we assume that the ionization energies of the molecules and atoms in the bubble decrease as the gas density increases and that the decrease of the ionization energy reaches about 60%-70% as the bubble flashes, which is difficult to explain by using previous models. Project supported by the Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20120002110031) and the National Natural Science Foundation of China (Grant No. 11334005).

  1. Nocturnal ultrasound measurements of optic nerve sheath diameter correlate with intracranial pressure in children with craniosynostosis.

    PubMed

    Driessen, Caroline; van Veelen, Marie-Lise C; Lequin, Maarten; Joosten, Koen F M; Mathijssen, Irene M J

    2012-09-01

    Children with craniosynostosis are at risk for increased intracranial pressure, and additional possibilities to screen for increased intracranial pressure are required. The authors' aim was to use ultrasound measurements of the optic nerve sheath to understand and express the variability of intracranial pressure in syndromic craniosynostosis. Therefore, five pediatric patients with craniosynostosis underwent invasive 24-hour intracranial pressure monitoring and simultaneous optic nerve sheath measurements. In three patients, the intracranial pressure was abnormal, and during the second half of the night, the optic nerve sheath was increased in all three patients. The optic nerve sheath diameter changes during the night and is as dynamic as the intracranial pressure. To the best of their knowledge, the authors are the first to describe a real-time relationship of the optic nerve sheath with increased intracranial pressure in children.

  2. Radiological anatomical consideration of conjoined nerve root with a case review

    PubMed Central

    Oh, Chang Hyun; Park, Jae Suk; Choi, Won-Seok; Choi, Eunhwa

    2013-01-01

    Nerve root anomalies are frequently underrecognized regardless of the advances in imaging studies; they are also underappreciated and underreported when encountered surgically. The classification of conjoined nerve roots is based on whether the nerve root emerges at an abnormal level or from an anastomotic branch. In the present report, we describe case with a conjoined nerve root that emerged at a more caudal level than that normally observed that was an undiagnosed on preoperative imaging studies. We also discuss the atypical imaging features obtained through preoperative imaging studies. As observed in the present case, preoperative recognition and diagnosis of such anomalies offer the best opportunity of performing a successful procedure and preventing inadvertent damage to nerve roots intraoperatively. PMID:24386602

  3. Nerve Cross-Bridging to Enhance Nerve Regeneration in a Rat Model of Delayed Nerve Repair

    PubMed Central

    2015-01-01

    There are currently no available options to promote nerve regeneration through chronically denervated distal nerve stumps. Here we used a rat model of delayed nerve repair asking of prior insertion of side-to-side cross-bridges between a donor tibial (TIB) nerve and a recipient denervated common peroneal (CP) nerve stump ameliorates poor nerve regeneration. First, numbers of retrogradely-labelled TIB neurons that grew axons into the nerve stump within three months, increased with the size of the perineurial windows opened in the TIB and CP nerves. Equal numbers of donor TIB axons regenerated into CP stumps either side of the cross-bridges, not being affected by target neurotrophic effects, or by removing the perineurium to insert 5-9 cross-bridges. Second, CP nerve stumps were coapted three months after inserting 0-9 cross-bridges and the number of 1) CP neurons that regenerated their axons within three months or 2) CP motor nerves that reinnervated the extensor digitorum longus (EDL) muscle within five months was determined by counting and motor unit number estimation (MUNE), respectively. We found that three but not more cross-bridges promoted the regeneration of axons and reinnervation of EDL muscle by all the CP motoneurons as compared to only 33% regenerating their axons when no cross-bridges were inserted. The same 3-fold increase in sensory nerve regeneration was found. In conclusion, side-to-side cross-bridges ameliorate poor regeneration after delayed nerve repair possibly by sustaining the growth-permissive state of denervated nerve stumps. Such autografts may be used in human repair surgery to improve outcomes after unavoidable delays. PMID:26016986

  4. Optic nerve diameters and perimetric thresholds in idiopathic intracranial hypertension.

    PubMed Central

    Salgarello, T.; Tamburrelli, C.; Falsini, B.; Giudiceandrea, A.; Colotto, A.

    1996-01-01

    AIMS/BACKGROUND--Idiopathic intracranial hypertension (IIH) is a central nervous disorder characterised by abnormally increased cerebrospinal fluid (CSF) pressure leading to optic nerve compression. An indirect estimate of increased CSF pressure can be obtained by the ultrasonographic determination of optic nerve sheaths diameters. Computerised static perimetry is regarded as the method of choice for monitoring the course of the optic neuropathy in IIH. The aims were to compare the echographic optic nerve diameters (ONDs) and the perimetric thresholds of patients with IIH with those of age-matched controls, and to examine the correlation between these two variables in individual patients with papilloedema. METHODS--Standardised A-scan echography of the mid orbital optic nerve transverse diameters and automated threshold perimetry (Humphrey 30-2) were performed in 20 patients with IIH with variable degree of papilloedema (according to the Frisén scheme) and no concomitant ocular diseases. Echographic and perimetric results were compared with those obtained from 20 age-matched controls. RESULTS--When compared with controls, patients with IIH showed a significant increase in mean ONDs and significantly reduced mean perimetric sensitivities. In individual patients with papilloedema, the transverse ONDs correlated negatively with Humphrey mean deviation values and positively with pattern standard deviation values. CONCLUSION--These results indicate that OND changes in IIH are associated with perimetric threshold losses, and suggest that IIH functional deficits may be related to the degree of distension of optic nerve sheaths as a result of an increased CSF pressure. PMID:8759260

  5. Abnormal hematological indices in cirrhosis

    PubMed Central

    Qamar, Amir A; Grace, Norman D

    2009-01-01

    Abnormalities in hematological indices are frequently encountered in cirrhosis. Multiple causes contribute to the occurrence of hematological abnormalities. Recent studies suggest that the presence of hematological cytopenias is associated with a poor prognosis in cirrhosis. The present article reviews the pathogenesis, incidence, prevalence, clinical significance and treatment of abnormal hematological indices in cirrhosis. PMID:19543577

  6. Abnormal Grain Growth Suppression in Aluminum Alloys

    NASA Technical Reports Server (NTRS)

    Hales, Stephen J. (Inventor); Claytor, Harold Dale (Inventor); Alexa, Joel A. (Inventor)

    2015-01-01

    The present invention provides a process for suppressing abnormal grain growth in friction stir welded aluminum alloys by inserting an intermediate annealing treatment ("IAT") after the welding step on the article. The IAT may be followed by a solution heat treatment (SHT) on the article under effectively high solution heat treatment conditions. In at least some embodiments, a deformation step is conducted on the article under effective spin-forming deformation conditions or under effective superplastic deformation conditions. The invention further provides a welded article having suppressed abnormal grain growth, prepared by the process above. Preferably the article is characterized with greater than about 90% reduction in area fraction abnormal grain growth in any friction-stir-welded nugget.

  7. The development of a normalization method for comparing nerve regeneration effectiveness among different graft types.

    PubMed

    Chang, Wei; DeVince, Jeffrey; Green, Gabriella; Shah, Munish Bhupendra; Johns, Michael S; Meng, Yan; Yu, Xiaojun

    2013-12-01

    The inability to compare directly different nerve grafts has been a significant factor hindering the advance of nerve graft development. Due to the abundance of variables that exist in nerve graft construction and multiple assessment types, there has been limited success in comparing nerve graft effectiveness among experiments. Using mathematical techniques on nerve conduction velocity (NCV) autograft data, a normalization function was empirically derived that normalizes differences in gap lengths. Further analysis allowed for the development of the relative regeneration ratio (RRR). The RRR function allows researchers to directly compare nerve graft results based on the NCV data from their respective studies as long as the data was collected at the same post-operation time. This function also allows for comparisons between grafts tested at different gap lengths. Initial testing of this RRR function provided confidence that the function is accurate for a continuum of gap lengths and different nerve graft types. PMID:24118184

  8. Spirometric abnormalities among welders

    SciTech Connect

    Rastogi, S.K.; Gupta, B.N.; Husain, T.; Mathur, N.; Srivastava, S. )

    1991-10-01

    A group of manual welders age group 13-60 years having a mean exposure period of 12.4 {plus minus} 1.12 years were subjected to spirometry to evaluate the prevalence of spirometric abnormalities. The welders showed a significantly higher prevalence of respiratory impairment than that observed among the unexposed controls as a result of exposure to welding gases which comprised fine particles of lead, zinc, chromium, and manganese. This occurred despite the lower concentration of the pollutants at the work place. In the expose group, the smoking welders showed a prevalence of respiratory impairment significantly higher than that observed in the nonsmoking welders. The results of the pulmonary function tests showed a predominantly restrictive type of pulmonary impairment followed by a mixed ventilatory defect among the welders. The effect of age on pulmonary impairment was not discernible. Welders exposed for over 10 years showed a prevalence of respiratory abnormalities significantly higher than those exposed for less than 10 years. Smoking also had a contributory role.

  9. [Imaging anatomy of cranial nerves].

    PubMed

    Hermier, M; Leal, P R L; Salaris, S F; Froment, J-C; Sindou, M

    2009-04-01

    Knowledge of the anatomy of the cranial nerves is mandatory for optimal radiological exploration and interpretation of the images in normal and pathological conditions. CT is the method of choice for the study of the skull base and its foramina. MRI explores the cranial nerves and their vascular relationships precisely. Because of their small size, it is essential to obtain images with high spatial resolution. The MRI sequences optimize contrast between nerves and surrounding structures (cerebrospinal fluid, fat, bone structures and vessels). This chapter discusses the radiological anatomy of the cranial nerves.

  10. Nerve-pulse interactions

    SciTech Connect

    Scott, A.C.

    1982-01-01

    Some recent experimental and theoretical results on mechanisms through which individual nerve pulses can interact are reviewed. Three modes of interactions are considered: (1) interaction of pulses as they travel along a single fiber which leads to velocity dispersion; (2) propagation of pairs of pulses through a branching region leading to quantum pulse code transformations; and (3) interaction of pulses on parallel fibers through which they may form a pulse assembly. This notion is analogous to Hebb's concept of a cell assembly, but on a lower level of the neural hierarchy.

  11. Retrograde axonal transport of /sup 125/I-nerve growth factor in rat ileal mesenteric nerves. Effect of streptozocin diabetes

    SciTech Connect

    Schmidt, R.E.; Plurad, S.B.; Saffitz, J.E.; Grabau, G.G.; Yip, H.K.

    1985-12-01

    The retrograde axonal transport of intravenously (i.v.) administered /sup 125/I-nerve growth factor (/sup 125/I-NGF) was examined in mesenteric nerves innervating the small bowel of rats with streptozocin (STZ) diabetes using methods described in detail in the companion article. The accumulation of /sup 125/I-NGF distal to a ligature on the ileal mesenteric nerves of diabetic animals was 30-40% less than in control animals. The inhibition of accumulation of /sup 125/I-NGF in diabetic animals was greater at a ligature tied 2 h after i.v. administration than at a ligature tied after 14 h, which suggests that the diabetic animals may have a lag in initiation of NGF transport in the terminal axon or retardation of transport at some site along the axon. The /sup 125/I-NGF transport defect was observed as early as 3 days after the induction of diabetes, a time before the development of structural axonal lesions, and did not worsen at later times when dystrophic axonopathy is present. Both the ileal mesenteric nerves, which eventually develop dystrophic axonopathy in experimental diabetes, and the jejunal mesenteric nerves, which never develop comparable structural alterations, showed similar /sup 125/I-NGF transport deficits, suggesting that the existence of the transport abnormality does not predict the eventual development of dystrophic axonal lesions. Autoradiographic localization of /sup 125/I-NGF in the ileal mesenteric nerves of animals that had been diabetic for 11-13 mo demonstrated decreased amounts of /sup 125/I-NGF in transit in unligated paravascular nerve fascicles. There was, however, no evidence for focal retardation of transported /sup 125/I-NGF at the sites of dystrophic axonal lesions.

  12. Microsurgical treatment of peripheral nerve injuries.

    PubMed

    Dolene, V

    1977-01-01

    In the period from 1972 to 1976, 536 patients with injuries of the peripheral nerves were treated at the Neurosurgical University Clinic Lyublyana. The treatment was performed according to the principles of microsurgery. Preoperative and postoperative supervision included EMG, electroneurography and nerve conduction speed. Subdivision: N. facialis 6, plexus brachialis 78, n. radialis 58, n. medianus 189, n. ulnaris 212, n. ischiadicus 17, n. femoralis 3, n. tibialis 12, n. fibularis 37. On the plexus brachialis 50 funiculolyses and 28 raphies were carried out. Immobilisation for 10 days. The length of the transplants showed no negative influence. After-observation was necessary for three and more years, especially in case of plexus injuries. Complete restoration was only found in children. Sensitivity in 80% more than Seddon III, 17% III and 3% less than III. Motor function in 60% IV, 20% III, 12% II and 8% less than II.

  13. Magnetoneurography: theory and application to peripheral nerve disorders.

    PubMed

    Mackert, Bruno-Marcel

    2004-12-01

    Magnetoneurography (MNG) is a non-invasive method to trace and visualize three-dimensionally the propagation path of compound action currents (CAC) along peripheral nerves. The basic physical and physiological principle is the mapping of extremely weak magnetic fields generated by the intraaxonal longitudinal ion flows of evoked nerval CAC using SQUID sensors (Superconducting Quantum Interference Devices). During recent years, MNG protocols have been established which allow for a non-invasive spatiotemporal tracing of impulse propagation along peripheral nerves in humans and in particular along proximal nerve segments in a clinical setting. Thereby, the three-dimensional path, the local nerve conduction velocity, the length and strength of the CAC de- and repolarization phase have been reconstructed. First recordings in patients demonstrated that the method is sensitive enough to detect and to localize nerve conduction anomalities along nerve roots, as, e.g. caused by lumbosacral disc herniation. This review on MNG will focus on those studies which provide data from humans and thereby reveal perspectives for its future clinical applications. PMID:15546775

  14. Magnetoneurography: theory and application to peripheral nerve disorders.

    PubMed

    Mackert, Bruno-Marcel

    2004-12-01

    Magnetoneurography (MNG) is a non-invasive method to trace and visualize three-dimensionally the propagation path of compound action currents (CAC) along peripheral nerves. The basic physical and physiological principle is the mapping of extremely weak magnetic fields generated by the intraaxonal longitudinal ion flows of evoked nerval CAC using SQUID sensors (Superconducting Quantum Interference Devices). During recent years, MNG protocols have been established which allow for a non-invasive spatiotemporal tracing of impulse propagation along peripheral nerves in humans and in particular along proximal nerve segments in a clinical setting. Thereby, the three-dimensional path, the local nerve conduction velocity, the length and strength of the CAC de- and repolarization phase have been reconstructed. First recordings in patients demonstrated that the method is sensitive enough to detect and to localize nerve conduction anomalities along nerve roots, as, e.g. caused by lumbosacral disc herniation. This review on MNG will focus on those studies which provide data from humans and thereby reveal perspectives for its future clinical applications.

  15. Electrodiagnosis of carpal tunnel syndrome: which transcarpal conduction technique is best?

    PubMed

    Chang, Ming-Hong; Liao, Yi-Chu; Lee, Yi-Chung; Hsieh, Peiyuan F; Liu, Lu-Han

    2009-10-01

    Transcarpal conduction techniques are commonly used to be supplementary techniques to distal sensory and motor latencies (DSL and DML) in the electrodiagnosis of carpal tunnel syndrome (CTS). However, which transcarpal conduction techniques, or combination of techniques, are the most sensitive for the electrodiagnosis of CTS is unknown. To determine which transcarpal conduction technique is the most sensitive for the electrodiagnosis of CTS, we prospectively conduct this study. Study subjects were 100 patients with CTS and 50 controls. In addition to DSL and DML determinations, all subjects were evaluated using four transcarpal conduction techniques. These were (1) median wrist-palm sensory conduction time (W-Psen CT); (2) median wrist-palm mixed nerve conduction time (W-Pmix CT); (3) the difference of conduction time across wrist between median and ulnar nerves (W-Pmix M-U CT); and (4) median wrist-palm motor conduction velocity (W-Pmot CV). The sensitivities and specificities of these tests were compared. Ninety patients had one or more electrophysiologic abnormalities. The DSL and DML diagnostic sensitivities were 74% and 72%, respectively. Better sensitivities were obtained with W-Psen CT (82%), W-Pmot CV (81%), W-Pmix CT (78%), and W-Pmix M-U CT (79%). Compared between four transcarpal conduction techniques, there was no significant difference in sensitivity. Of 26 patients with CTS with normal DSL, additional electrophysiologic abnormalities were revealed with W-Psen CT (30.7%), W-Pmot CV (53.8%), W-Pmix CT (30.7%), or W-Pmix M-U CT (38.5%). When W-Pmot CV was compared with W-Psen CT and W-Pmot CV versus W-Pmix CT, calculated probabilities (P = 0.07) showed a clear trend toward statistical significance. Furthermore, of 20 patients with normal DSL and DML, five patients had abnormality for W-Psen CT, eight for W-Pmot CV, four for W-Pmix CT, and six for W-Pmix M-U CT. On the basis of the results, we concluded that the most simple and reliable transcarpal

  16. Ionic channels and hormone release from peptidergic nerve terminals.

    PubMed

    Lemos, J R; Nordmann, J J

    1986-09-01

    Although there is considerable evidence that depolarization of nerve cell terminals leads to the entry of Ca2+ and to the secretion of neurohormones and neurotransmitters, the details of how ionic currents control the release of neuroactive substances from nerve terminals are unknown. The small size of most nerve terminals has precluded direct analysis of membrane ionic currents and their influence on secretion. We now report that it is possible, using patch-clamp techniques, to study stimulus--secretion coupling in isolated peptidergic nerve terminals. Sinus gland terminals from Cardisoma are easily isolated following collagenase treatment and appear morphologically and electrically very similar to non-dissociated nerve endings. We have observed two types of single-channel currents not previously described. The first ('f') channel is activated by intracellular Na+ and the second ('s') by intracellular Ca2+. Both show little selectivity between Na+ and K+. In symmetrical K+, these cation channels have mean conductances of 69 and 213 pS, respectively. Furthermore, at least three types of Ca2+ channels can be reconstituted from nerve terminal membranes prepared from sinus glands. Nerve terminals can also be isolated from the rat neural lobe. These neurosecretosomes release oxytocin and vasopressin, in response to membrane depolarization, only in the presence of external Ca2+. The depolarization of the nerve endings is associated with an increase in intracellular free Ca2+ concentration and this increase, measured using a fluorescent indicator, is abolished by Ca2+ channel blockers. Channels similar in their properties to the f and s channels also exist in rat neural lobe endings. Since these channels have not been found in other neurones or neuronal structures they may be unique to peptidergic nerve terminals.

  17. Laser-activated protein bands for peripheral nerve repair

    NASA Astrophysics Data System (ADS)

    Lauto, Antonio; Trickett, Rodney I.; Malik, Richard; Dawes, Judith M.; Owen, Earl R.

    1996-01-01

    A 100 micrometer core optical fiber-coupled 75 mW diode laser operating at a wavelength of 800 nm has been used in conjunction with a protein solder to stripe weld severed rat tibial nerves, reducing the long operating time required for microsurgical nerve repair. Welding is produced by selective laser denaturation of the protein based solder which contains the dye indocyanine green. Operating time for laser soldering was 10 plus or minus 5 min. (n equals 24) compared to 23 plus or minus 9 min (n equals 13) for microsuturing. The laser solder technique resulted in patent welds with a tensile strength of 15 plus or minus 5 g, while microsutured nerves had a tensile strength of 40 plus or minus 10 g. Histopathology of the laser soldered nerves, conducted immediately after surgery, displayed solder adhesion to the outer membrane with minimal damage to the inner axons of the nerves. An in vivo study, with a total of fifty-seven adult male wistar rats, compared laser solder repaired tibial nerves to conventional microsuture repair. Twenty-four laser soldered nerves and thirteen sutured nerves were characterized at three months and showed successful regeneration with average compound muscle action potentials (CMAP) of 2.4 plus or minus 0.7 mV and 2.7 plus or minus 0.8 mV respectively. Histopathology of the in vivo study, confirmed the comparable regeneration of axons in laser and suture operated nerves. A faster, less damaging and long lasting laser based anastomotic technique is presented.

  18. Local administration of icariin contributes to peripheral nerve regeneration and functional recovery.

    PubMed

    Chen, Bo; Niu, Su-Ping; Wang, Zhi-Yong; Wang, Zhen-Wei; Deng, Jiu-Xu; Zhang, Pei-Xun; Yin, Xiao-Feng; Han, Na; Kou, Yu-Hui; Jiang, Bao-Guo

    2015-01-01

    Our previous study showed that systemic administration of the traditional Chinese medicine Epimedium extract promotes peripheral nerve regeneration. Here, we sought to explore the therapeutic effects of local administration of icariin, a major component of Epimedium extract, on peripheral nerve regeneration. A poly(lactic-co-glycolic acid) biological conduit sleeve was used to bridge a 5 mm right sciatic nerve defect in rats, and physiological saline, nerve growth factor, icariin suspension, or nerve growth factor-releasing microsphere suspension was injected into the defect. Twelve weeks later, sciatic nerve conduction velocity and the number of myelinated fibers were notably greater in the rats treated with icariin suspension or nerve growth factor-releasing microspheres than those that had received nerve growth factor or physiological saline. The effects of icariin suspension were similar to those of nerve growth factor-releasing microspheres. These data suggest that icariin acts as a nerve growth factor-releasing agent, and indicate that local application of icariin after spinal injury can promote peripheral nerve regeneration. PMID:25788925

  19. Functions of the Renal Nerves.

    ERIC Educational Resources Information Center

    Koepke, John P.; DiBona, Gerald F.

    1985-01-01

    Discusses renal neuroanatomy, renal vasculature, renal tubules, renin secretion, renorenal reflexes, and hypertension as related to renal nerve functions. Indicates that high intensitites of renal nerve stimulation have produced alterations in several renal functions. (A chart with various stimulations and resultant renal functions and 10-item,…

  20. Sports and peripheral nerve injury.

    PubMed

    Hirasawa, Y; Sakakida, K

    1983-01-01

    Peripheral nerve injury is one of the serious complications of athletic injuries; however, they have rarely been reported. According to the report by Takazawa et al., there were only 28 cases of peripheral nerve injury among 9,550 cases of sports injuries which had been treated in the previous 5 years at the clinic of the Japanese Athletic Association. The authors have encountered 1,167 cases of peripheral nerve injury during the past 18 years. Sixty-six of these cases were related to sports (5.7%). The nerves most frequently involved were: brachial plexus, radial nerve, ulnar, peroneal, and axillary nerves (in their order of frequency). The most common causes of such injuries were mountain climbing, gymnastics, and baseball. More often, peripheral nerve injury seemed to be caused by continuous compression and repeated trauma to the involved nerve. Usually it appeared as an entrapment neuropathy and the symptoms could be improved by conservative treatment. Some of the cases were complicated by fractures and surgical exploration became necessary. Results of treatment produced excellent to good improvement in 87.9% of the cases. With regard to compartment syndrome, the authors stress the importance of early and precise diagnosis and a fasciotomy.

  1. Effect of Collateral Sprouting on Donor Nerve Function After Nerve Coaptation: A Study of the Brachial Plexus

    PubMed Central

    Reichert, Paweł; Kiełbowicz, Zdzisław; Dzięgiel, Piotr; Puła, Bartosz; Wrzosek, Marcin; Bocheńska, Aneta; Gosk, Jerzy

    2016-01-01

    Background The aim of the present study was to evaluate the donor nerve from the C7 spinal nerve of the rabbit brachial plexus after a coaptation procedure. Assessment was performed of avulsion of the C5 and C6 spinal nerves treated by coaptation of these nerves to the C7 spinal nerve. Material/Methods After nerve injury, fourteen rabbits were treated by end-to-side coaptation (ETS), and fourteen animals were treated by side-to-side coaptation (STS) on the right brachial plexus. Electrophysiological and histomorphometric analyses and the skin pinch test were used to evaluate the outcomes. Results There was no statistically significant difference in the G-ratio proximal and distal to the coaptation in the ETS group, but the differences in the axon, myelin sheath and fiber diameters were statistically significant. The comparison of the ETS and STS groups distal to the coaptation with the controls demonstrated statistically significant differences in the fiber, axon, and myelin sheath diameters. With respect to the G-ratio, the ETS group exhibited no significant differences relative to the control, whereas the G-ratio in the STS group and the controls differed significantly. In the electrophysiological study, the ETS and STS groups exhibited major changes in the biceps and subscapularis muscles. Conclusions The coaptation procedure affects the histological structure of the nerve donor, but it does not translate into changes in nerve conduction or the sensory function of the limb. The donor nerve lesion in the ETS group is transient and has minimal clinical relevance. PMID:26848925

  2. Ultrasonographic Evaluation of Peripheral Nerves.

    PubMed

    Ali, Zarina S; Pisapia, Jared M; Ma, Tracy S; Zager, Eric L; Heuer, Gregory G; Khoury, Viviane

    2016-01-01

    There are a variety of imaging modalities for evaluation of peripheral nerves. Of these, ultrasonography (US) is often underused. There are several advantages of this imaging modality, including its cost-effectiveness, time-efficient assessment of long segments of peripheral nerves, ability to perform dynamic maneuvers, lack of contraindications, portability, and noninvasiveness. It can provide diagnostic information that cannot be obtained by electrophysiologic or, in some cases, magnetic resonance imaging studies. Ideally, the neurosurgeon can use US as a diagnostic adjunct in the preoperative assessment of a patient with traumatic, neoplastic, infective, or compressive nerve injury. Perhaps its most unique use is in intraoperative surgical planning. In this article, a brief description of normal US nerve anatomy is presented followed by a description of the US appearance of peripheral nerve disease caused by trauma, tumor, infection, and entrapment.

  3. Peripheral nerve conduits: technology update

    PubMed Central

    Arslantunali, D; Dursun, T; Yucel, D; Hasirci, N; Hasirci, V

    2014-01-01

    Peripheral nerve injury is a worldwide clinical problem which could lead to loss of neuronal communication along sensory and motor nerves between the central nervous system (CNS) and the peripheral organs and impairs the quality of life of a patient. The primary requirement for the treatment of complete lesions is a tension-free, end-to-end repair. When end-to-end repair is not possible, peripheral nerve grafts or nerve conduits are used. The limited availability of autografts, and drawbacks of the allografts and xenografts like immunological reactions, forced the researchers to investigate and develop alternative approaches, mainly nerve conduits. In this review, recent information on the various types of conduit materials (made of biological and synthetic polymers) and designs (tubular, fibrous, and matrix type) are being presented. PMID:25489251

  4. Teeth and tooth nerves.

    PubMed

    Hildebrand, C; Fried, K; Tuisku, F; Johansson, C S

    1995-02-01

    (1) Although our knowledge on teeth and tooth nerves has increased substantially during the past 25 years, several important issues remain to be fully elucidated. As a result of the work now going on at many laboratories over the world, we can expect exciting new findings and major break-throughs in these and other areas in a near future. (2) Dentin-like and enamel-like hard tissues evolved as components of the exoskeletal bony armor of early vertebrates, 500 million years ago, long before the first appearance of teeth. It is possible that teeth developed from tubercles (odontodes) in the bony armor. The presence of a canal system in the bony plates, of tubular dentin, of external pores in the enamel layer and of a link to the lateral line system promoted hypotheses that the bony plates and tooth precursors may have had a sensory function. The evolution of an efficient brain, of a head with paired sense organs and of toothed jaws concurred with a shift from a sessile filter-feeding life to active prey hunting. (3) The wide spectrum of feeding behaviors exhibited by modern vertebrates is reflected by a variety of dentition types. While the teeth are continuously renewed in toothed non-mammalian vertebrates, tooth turnover is highly restricted in mammals. As a rule, one set of primary teeth is replaced by one set of permanent teeth. Since teeth are richly innervated, the turnover necessitates a local neural plasticity. Another factor calling for a local plasticity is the relatively frequent occurrence of age-related and pathological dental changes. (4) Tooth development is initiated through interactions between the oral epithelium and underlying neural crest-derived mesenchymal cells. The interactions are mediated by cell surface molecules, extracellular matrix molecules and soluble molecules. The possibility that the initiating events might involve a neural component has been much discussed. With respect to mammals, the experimental evidence available does not

  5. Peripheral nerve blocks for distal extremity surgery.

    PubMed

    Offierski, Chris

    2013-10-01

    Peripheral nerve block is well suited for distal extremity surgery. Blocking the nerves at the distal extremity is easily done. It does not require ultrasound or stimulators to identify the nerve. Blocking nerves in the distal extremity is safe with low risk of toxicity. The effect of the nerve block is limited to the distribution of the nerve. The distal nerves in the lower extremity are sensory branches of the sciatic nerve. This provides a sensory block only. This has the advantage of allowing the patient to actively contract tendons in the foot and ambulate more quickly after surgery. PMID:24093651

  6. Can "dor to dor+rec neurorrhaphy" by biodegradable chitin conduit be a new method for peripheral nerve injury?

    PubMed

    Yin, Xiao Feng; Kou, Yu Hui; Wang, Yan Hua; Zhang, Peixun; Zhang, Dian Yin; Fu, Zhong Guo; Zhang, Hong Bo; Jiang, Bao Guo

    2011-04-01

    This study aims to estimate the effects of using one donor nerve to repair the injured nerve and itself simultaneously by biodegradable chitin conduit. Proximal median nerve served as donor nerve to repair the distal median and whole ulnar nerve. Four months postoperation, the number of myelinated axons and nerve conduction velocities of the distal median and ulnar nerve were (2085 ± 215 and 24.4 ± 5.9 m/s), and (1193 ± 102 and 30.7 ± 11.2 m/s). Recovery of the tetanic muscle forces of the reinvervated muscles were also observed. It suggests that Dor to Dor+Rec neurorrhaphy is a practical method for severe peripheral nerve injury.

  7. Electroactive biocompatible materials for nerve cell stimulation

    NASA Astrophysics Data System (ADS)

    Yang, Mei; Liang, Youlong; Gui, Qingyuan; Chen, Jun; Liu, Yong

    2015-04-01

    In the past decades, great efforts have been developed for neurobiologists and neurologists to restore nervous system functions. Recently much attention has been paid to electrical stimulation (ES) of the nervous system as a potential way to repair it. Various conductive biocompatible materials with good electrical conductivity, biocompatibility, and long-term ES or electrical stability have been developed as the substrates for ES. In this review, we summarized different types of materials developed in the purpose for ES of nervous system, including conducting polymers, carbon nanomaterials and composites from conducting polymer/carbon nanomaterials. The present review will give our perspective on the future research directions for further investigation on development of ES particularly on the nerve system.

  8. Ictal Cardiac Ryhthym Abnormalities

    PubMed Central

    Ali, Rushna

    2016-01-01

    Cardiac rhythm abnormalities in the context of epilepsy are a well-known phenomenon. However, they are under-recognized and often missed. The pathophysiology of these events is unclear. Bradycardia and asystole are preceded by seizure onset suggesting ictal propagation into the cortex impacting cardiac autonomic function, and the insula and amygdala being possible culprits. Sudden unexpected death in epilepsy (SUDEP) refers to the unanticipated death of a patient with epilepsy not related to status epilepticus, trauma, drowning, or suicide. Frequent refractory generalized tonic-clonic seizures, anti-epileptic polytherapy, and prolonged duration of epilepsy are some of the commonly identified risk factors for SUDEP. However, the most consistent risk factor out of these is an increased frequency of generalized tonic–clonic seizures (GTC). Prevention of SUDEP is extremely important in patients with chronic, generalized epilepsy. Since increased frequency of GTCS is the most consistently reported risk factor for SUDEP, effective seizure control is the most important preventive strategy. PMID:27347227

  9. Ictal Cardiac Ryhthym Abnormalities.

    PubMed

    Ali, Rushna

    2016-01-01

    Cardiac rhythm abnormalities in the context of epilepsy are a well-known phenomenon. However, they are under-recognized and often missed. The pathophysiology of these events is unclear. Bradycardia and asystole are preceded by seizure onset suggesting ictal propagation into the cortex impacting cardiac autonomic function, and the insula and amygdala being possible culprits. Sudden unexpected death in epilepsy (SUDEP) refers to the unanticipated death of a patient with epilepsy not related to status epilepticus, trauma, drowning, or suicide. Frequent refractory generalized tonic-clonic seizures, anti-epileptic polytherapy, and prolonged duration of epilepsy are some of the commonly identified risk factors for SUDEP. However, the most consistent risk factor out of these is an increased frequency of generalized tonic-clonic seizures (GTC). Prevention of SUDEP is extremely important in patients with chronic, generalized epilepsy. Since increased frequency of GTCS is the most consistently reported risk factor for SUDEP, effective seizure control is the most important preventive strategy. PMID:27347227

  10. Communication and abnormal behaviour.

    PubMed

    Crown, S

    1979-01-01

    In this paper the similarities between normal and abnormal behaviour are emphasized and selected aspects of communication, normal and aberrant, between persons are explored. Communication in a social system may be verbal or non-verbal: one person's actions cause a response in another person. This response may be cognitive, behavioural or physiological. Communication may be approached through the individual, the social situation or social interaction. Psychoanalysis approaches the individual in terms of the coded communications of psychoneurotic symptoms or psychotic behaviour; the humanist-existential approach is concerned more with emotional expression. Both approaches emphasize the development of individual identity. The interaction between persons and their social background is stressed. Relevant are sociological concepts such as illness behaviour, stigma, labelling, institutionalization and compliance. Two approaches to social interactions are considered: the gamesplaying metaphor, e.g. back pain as a psychosocial manipulation--the 'pain game'; and the 'spiral of reciprocal perspectives' which emphasizes the interactional complexities of social perceptions. Communicatory aspects of psychological treatments are noted: learning a particular metaphor such as 'resolution' of the problem (psychotherapy), learning more 'rewarding' behaviour (learning theory) or learning authenticity or self-actualization (humanist-existential).

  11. Communication and abnormal behaviour.

    PubMed

    Crown, S

    1979-01-01

    In this paper the similarities between normal and abnormal behaviour are emphasized and selected aspects of communication, normal and aberrant, between persons are explored. Communication in a social system may be verbal or non-verbal: one person's actions cause a response in another person. This response may be cognitive, behavioural or physiological. Communication may be approached through the individual, the social situation or social interaction. Psychoanalysis approaches the individual in terms of the coded communications of psychoneurotic symptoms or psychotic behaviour; the humanist-existential approach is concerned more with emotional expression. Both approaches emphasize the development of individual identity. The interaction between persons and their social background is stressed. Relevant are sociological concepts such as illness behaviour, stigma, labelling, institutionalization and compliance. Two approaches to social interactions are considered: the gamesplaying metaphor, e.g. back pain as a psychosocial manipulation--the 'pain game'; and the 'spiral of reciprocal perspectives' which emphasizes the interactional complexities of social perceptions. Communicatory aspects of psychological treatments are noted: learning a particular metaphor such as 'resolution' of the problem (psychotherapy), learning more 'rewarding' behaviour (learning theory) or learning authenticity or self-actualization (humanist-existential). PMID:261653

  12. Abnormal uterine bleeding.

    PubMed

    Whitaker, Lucy; Critchley, Hilary O D

    2016-07-01

    Abnormal uterine bleeding (AUB) is a common and debilitating condition with high direct and indirect costs. AUB frequently co-exists with fibroids, but the relationship between the two remains incompletely understood and in many women the identification of fibroids may be incidental to a menstrual bleeding complaint. A structured approach for establishing the cause using the Fédération International de Gynécologie et d'Obstétrique (FIGO) PALM-COEIN (Polyp, Adenomyosis, Leiomyoma, Malignancy (and hyperplasia), Coagulopathy, Ovulatory disorders, Endometrial, Iatrogenic and Not otherwise classified) classification system will facilitate accurate diagnosis and inform treatment options. Office hysteroscopy and increasing sophisticated imaging will assist provision of robust evidence for the underlying cause. Increased availability of medical options has expanded the choice for women and many will no longer need to recourse to potentially complicated surgery. Treatment must remain individualised and encompass the impact of pressure symptoms, desire for retention of fertility and contraceptive needs, as well as address the management of AUB in order to achieve improved quality of life. PMID:26803558

  13. Abortion for fetal abnormality.

    PubMed

    Maclean, N E

    1979-07-25

    I wish to thank Dr. Pauline Bennett for her reply (NZ Med J, 13 June). She has demonstrated well that in dealing with sensitive difficult issues such as abortion for fetal abnormality, the one thing the doctor is not recommended to do is to speak the truth] I am prompted to write this letter for 2 reasons. Firstly, the excellent letter written by Dr. A. M. Rutherford (NZ Med J, 13 June) on the subject of abortion stated, "The most disturbing feature about the whole controversy is the 'blunting of our conscience'." When the doctors are not encouraged to be honest with patients then indeed our conscience has been blunted. Secondly, I watched Holocaust last night, and cannot refrain from stating that I see frightening parallels between our liberal abortion policy and the activities of the Nazis. As I watched the "mental patients" being herded into the shed for gassing by the polite, tidy, white coated medical staff, and then heard the compassionate, sensitive, letter of the hospital authorities to the relatives of the deceased, the parallel became obvious. The mental patients were weak, defenseless, burdensome, and uneconomic; the unborn are weak, defenseless, burdensome, and uneconomic. The hospital authority's letter was acceptable in many ways, acceptable except that its words bore no relation to the truth. It is said that the "first casualty of war is the truth". Whether that war involves the Jews, or the insane, or the unborn, the statement would seem correct.

  14. Management of peripheral facial nerve palsy

    PubMed Central

    2008-01-01

    Peripheral facial nerve palsy (FNP) may (secondary FNP) or may not have a detectable cause (Bell’s palsy). Three quarters of peripheral FNP are primary and one quarter secondary. The most prevalent causes of secondary FNP are systemic viral infections, trauma, surgery, diabetes, local infections, tumor, immunological disorders, or drugs. The diagnosis of FNP relies upon the presence of typical symptoms and signs, blood chemical investigations, cerebro-spinal-fluid-investigations, X-ray of the scull and mastoid, cerebral MRI, or nerve conduction studies. Bell’s palsy may be diagnosed after exclusion of all secondary causes, but causes of secondary FNP and Bell’s palsy may coexist. Treatment of secondary FNP is based on the therapy of the underlying disorder. Treatment of Bell’s palsy is controversial due to the lack of large, randomized, controlled, prospective studies. There are indications that steroids or antiviral agents are beneficial but also studies, which show no beneficial effect. Additional measures include eye protection, physiotherapy, acupuncture, botulinum toxin, or possibly surgery. Prognosis of Bell’s palsy is fair with complete recovery in about 80% of the cases, 15% experience some kind of permanent nerve damage and 5% remain with severe sequelae. PMID:18368417

  15. Management of peripheral facial nerve palsy.

    PubMed

    Finsterer, Josef

    2008-07-01

    Peripheral facial nerve palsy (FNP) may (secondary FNP) or may not have a detectable cause (Bell's palsy). Three quarters of peripheral FNP are primary and one quarter secondary. The most prevalent causes of secondary FNP are systemic viral infections, trauma, surgery, diabetes, local infections, tumor, immunological disorders, or drugs. The diagnosis of FNP relies upon the presence of typical symptoms and signs, blood chemical investigations, cerebro-spinal-fluid-investigations, X-ray of the scull and mastoid, cerebral MRI, or nerve conduction studies. Bell's palsy may be diagnosed after exclusion of all secondary causes, but causes of secondary FNP and Bell's palsy may coexist. Treatment of secondary FNP is based on the therapy of the underlying disorder. Treatment of Bell's palsy is controversial due to the lack of large, randomized, controlled, prospective studies. There are indications that steroids or antiviral agents are beneficial but also studies, which show no beneficial effect. Additional measures include eye protection, physiotherapy, acupuncture, botulinum toxin, or possibly surgery. Prognosis of Bell's palsy is fair with complete recovery in about 80% of the cases, 15% experience some kind of permanent nerve damage and 5% remain with severe sequelae.

  16. Recent advances in nerve tissue engineering.

    PubMed

    Zhang, Bill G X; Quigley, Anita F; Myers, Damian E; Wallace, Gordon G; Kapsa, Robert M I; Choong, Peter F M

    2014-04-01

    Nerve injury secondary to trauma, neurological disease or tumor excision presents a challenge for surgical reconstruction. Current practice for nerve repair involves autologous nerve transplantation, which is associated with significant donor-site morbidity and other complications. Previously artificial nerve conduits made from polycaprolactone, polyglycolic acid and collagen were approved by the FDA (USA) for nerve repair. More recently, there have been significant advances in nerve conduit design that better address the requirements of nerve regrowth. Innovations in materials science, nanotechnology, and biology open the way for the synthesis of new generation nerve repair conduits that address issues currently faced in nerve repair and regeneration. This review discusses recent innovations in this area, including the use of nanotechnology to improve the design of nerve conduits and to enhance nerve regeneration.

  17. 21 CFR 882.5830 - Implanted diaphragmatic/phrenic nerve stimulator.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Implanted diaphragmatic/phrenic nerve stimulator. 882.5830 Section 882.5830 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... which an abnormally low amount of air enters the lungs) caused by brain stem disease, high...

  18. 21 CFR 882.5830 - Implanted diaphragmatic/phrenic nerve stimulator.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Implanted diaphragmatic/phrenic nerve stimulator. 882.5830 Section 882.5830 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... which an abnormally low amount of air enters the lungs) caused by brain stem disease, high...

  19. 21 CFR 882.5830 - Implanted diaphragmatic/phrenic nerve stimulator.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Implanted diaphragmatic/phrenic nerve stimulator. 882.5830 Section 882.5830 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... which an abnormally low amount of air enters the lungs) caused by brain stem disease, high...

  20. Reduction in Retinal Nerve Fiber Layer Thickness in Young Adults with Autism Spectrum Disorders

    ERIC Educational Resources Information Center

    Emberti Gialloreti, Leonardo; Pardini, Matteo; Benassi, Francesca; Marciano, Sara; Amore, Mario; Mutolo, Maria Giulia; Porfirio, Maria Cristina; Curatolo, Paolo

    2014-01-01

    Recent years have seen an increase in the use of retinal nerve fiber layer (RNFL) evaluation as an easy-to-use, reproducible, proxy-measure of brain structural abnormalities. Here, we evaluated RNFL thickness in a group of subjects with high functioning autism (HFA) or with Asperger Syndrome (AS) to its potential as a tool to study autism…

  1. Malignant Peripheral Nerve Sheath Tumor.

    PubMed

    James, Aaron W; Shurell, Elizabeth; Singh, Arun; Dry, Sarah M; Eilber, Fritz C

    2016-10-01

    Malignant peripheral nerve sheath tumor (MPNST) is the sixth most common type of soft tissue sarcoma. Most MPNSTs arise in association with a peripheral nerve or preexisting neurofibroma. Neurofibromatosis type is the most important risk factor for MPNST. Tumor size and fludeoxyglucose F 18 avidity are among the most helpful parameters to distinguish MPNST from a benign peripheral nerve sheath tumor. The histopathologic diagnosis is predominantly a diagnosis of light microscopy. Immunohistochemical stains are most helpful to distinguish high-grade MPNST from its histologic mimics. Current surgical management of high-grade MPNST is similar to that of other high-grade soft tissue sarcomas. PMID:27591499

  2. Effects of deep heating provided by therapeutic ultrasound on demyelinating nerves.

    PubMed

    Aydin, Elif; Tastaban, Engin; Omurlu, Imran Kurt; Turan, Yasemin; Şendur, Ömer Faruk

    2016-04-01

    [Purpose] Physiotherapeutic heating agents are classified into two groups: superficial-heating agents and deep-heating agents. Therapeutic ultrasound is a deep-heating agent used to treat various musculosketal disorders. Numerous studies have attempted to determine the impact of ultrasound on healthy nerve conduction parameters. However, the instantaneous effects of deep heating via ultrasound on demyelinating nerves do not appear to have been described previously. The present study aimed to assess and compare the impact of ultrasound on demyelinating nerve and healthy nerve conduction parameters. [Subjects and Methods] Carpal tunnel syndrome was used as a focal demyelination model. Thirty-two hands of 25 participants with carpal tunnel syndrome were enrolled in the study. Ultrasound parameters were 3.3 MHz, 1.0 W/cm(2), 8 minutes, and continuous wave. Electrodiagnostic studies were performed initially, at the midpoint (4th min), and immediately after (8th min) ultrasound application. [Results] Reduced motor conduction velocity was found in demyelinating nerves at the 4th and 8th minutes. Ulnar nerve onset latency was significantly prolonged in the 8th minute recording, compared to the initial value. There were no significant differences in relative velocity and latency changes between demyelinating and normal nerves. [Conclusion] Deep heating via ultrasound may inversely affect conduction velocity in demyelinating nerves.

  3. Effects of deep heating provided by therapeutic ultrasound on demyelinating nerves

    PubMed Central

    Aydin, Elif; Tastaban, Engin; Omurlu, Imran Kurt; Turan, Yasemin; Şendur, Ömer Faruk

    2016-01-01

    [Purpose] Physiotherapeutic heating agents are classified into two groups: superficial-heating agents and deep-heating agents. Therapeutic ultrasound is a deep-heating agent used to treat various musculosketal disorders. Numerous studies have attempted to determine the impact of ultrasound on healthy nerve conduction parameters. However, the instantaneous effects of deep heating via ultrasound on demyelinating nerves do not appear to have been described previously. The present study aimed to assess and compare the impact of ultrasound on demyelinating nerve and healthy nerve conduction parameters. [Subjects and Methods] Carpal tunnel syndrome was used as a focal demyelination model. Thirty-two hands of 25 participants with carpal tunnel syndrome were enrolled in the study. Ultrasound parameters were 3.3 MHz, 1.0 W/cm2, 8 minutes, and continuous wave. Electrodiagnostic studies were performed initially, at the midpoint (4th min), and immediately after (8th min) ultrasound application. [Results] Reduced motor conduction velocity was found in demyelinating nerves at the 4th and 8th minutes. Ulnar nerve onset latency was significantly prolonged in the 8th minute recording, compared to the initial value. There were no significant differences in relative velocity and latency changes between demyelinating and normal nerves. [Conclusion] Deep heating via ultrasound may inversely affect conduction velocity in demyelinating nerves. PMID:27190467

  4. Humeral head translation after a suprascapular nerve block.

    PubMed

    San Juan, Jun G; Kosek, Peter; Karduna, Andrew R

    2013-08-01

    Subacromial impingement syndrome is the most common shoulder disorder. Abnormal superior translation of the humeral head is believed to be a major cause of this pathology. The first purpose of the study was to examine the effects of suprascapular nerve block on superior translation of the humeral head and scapular upward rotation during dynamic shoulder elevation. The secondary purpose was to assess muscle activation patterns during these motions. Twenty healthy subjects participated in the study. Using fluoroscopy and electromyography, humeral head translation and muscle activation were measured before and after a suprascapular nerve block. The humeral head was superiorly located at 60 degrees of humeral elevation, and the scapula was more upwardly rotated from 30 to 90 degrees of humeral elevation after the block. The differences were observed during midrange of motion. In addition, the deltoid muscle group demonstrated increased muscle activation after the nerve block. The study's results showed a compensatory increase in humeral head translation, scapular upward rotation, and deltoid muscle activation due to the nerve block. These outcomes suggest that increasing muscular strength and endurance of the supraspinatus and infraspinatus muscles could prevent any increased superior humeral head translation. This may be beneficial in reducing shoulder impingement or rotator cuff tears over time. PMID:22927503

  5. α-Synuclein pathology in the cranial and spinal nerves in Lewy body disease.

    PubMed

    Nakamura, Keiko; Mori, Fumiaki; Tanji, Kunikazu; Miki, Yasuo; Toyoshima, Yasuko; Kakita, Akiyoshi; Takahashi, Hitoshi; Yamada, Masahito; Wakabayashi, Koichi

    2016-06-01

    Accumulation of phosphorylated α-synuclein in neurons and glial cells is a histological hallmark of Lewy body disease (LBD) and multiple system atrophy (MSA). Recently, filamentous aggregations of phosphorylated α-synuclein have been reported in the cytoplasm of Schwann cells, but not in axons, in the peripheral nervous system in MSA, mainly in the cranial and spinal nerve roots. Here we conducted an immunohistochemical investigation of the cranial and spinal nerves and dorsal root ganglia of patients with LBD. Lewy axons were found in the oculomotor, trigeminal and glossopharyngeal-vagus nerves, but not in the hypoglossal nerve. The glossopharyngeal-vagus nerves were most frequently affected, with involvement in all of 20 subjects. In the spinal nerve roots, Lewy axons were found in all of the cases examined. Lewy axons in the anterior nerves were more frequent and numerous in the thoracic and sacral segments than in the cervical and lumbar segments. On the other hand, axonal lesions in the posterior spinal nerve roots appeared to increase along a cervical-to-sacral gradient. Although Schwann cell cytoplasmic inclusions were found in the spinal nerves, they were only minimal. In the dorsal root ganglia, axonal lesions were seldom evident. These findings indicate that α-synuclein pathology in the peripheral nerves is axonal-predominant in LBD, whereas it is restricted to glial cells in MSA.

  6. ‘Strategic Sequences’ in Adipose Derived Stem Cell Nerve Regeneration

    PubMed Central

    Widgerow, Alan D.; Salibian, Ara A.; Kohan, Emil; SartiniFerreira, Tadeu; Afzel, Hassaan; Tham, Thanh; Evans, Gregory RD

    2014-01-01

    Background Peripheral nerve injuries (PNI) are a major source of morbidity worldwide. The development of cellular regenerative therapies has the potential to improve outcomes of nerve injuries. However, an ideal therapy has yet to be found. The purpose of this study is to examine the current literature key points of regenerative techniques utilizing human adipose derived stem cells (hADSCs) for nerve regeneration, and derive a comprehensive approach to hADSC therapy for PNI. Methods A literature review was conducted using the electronic database PubMed to search for current experimental approaches to repairing peripheral nerve injuries using hADSCs. Key search elements focused on specific components of nerve regeneration paradigms, including, 1) support cells, 2) scaffolds and 3) nerve conduits. Results Strategic sequences were developed by optimizing the components of different experimental regenerative therapies. These sequences focus on priming hADSCs within a specialized growth medium, a hydrogel matrix base, and a collagen nerve conduit to achieve neuromodulatory nerve regeneration. Human ADSCs may exert their neuroregenerative influence through paracrine effects on surrounding Schwann cells in addition to physical interactions with injured tissue. Conclusions hADSCs may play a key role in nerve regeneration by acting primarily as support for local neurotrophic mediation and modulation of nerve growth rather than that of a primary neuronal differentiation agent. PMID:24375471

  7. Finite difference discretisation of a model for biological nerve conduction

    NASA Astrophysics Data System (ADS)

    Aderogba, A. A.; Chapwanya, M.; Jejeniwa, O. A.

    2016-06-01

    A nonstandard finite difference method is proposed for the discretisation of the semilinear FitzHugh-Nagumo reaction diffusion equation. The equation has been useful in describing, for example, population models, biological models, heat and mass transfer models, and many other applications. The proposed approach involves splitting the equation into the space independent and the time independent sub equation. Numerical simulations for the full equation are presented.

  8. Haem degradation in abnormal haemoglobins.

    PubMed Central

    Brown, S B; Docherty, J C

    1978-01-01

    The coupled oxidation of certain abnormal haemoglobins leads to different bile-pigment isomer distributions from that of normal haemoglobin. The isomer pattern may be correlated with the structure of the abnormal haemoglobin in the neighbourhood of the haem pocket. This is support for haem degradation by an intramolecular reaction. PMID:708385

  9. Systemic abnormalities in liver disease

    PubMed Central

    Minemura, Masami; Tajiri, Kazuto; Shimizu, Yukihiro

    2009-01-01

    Systemic abnormalities often occur in patients with liver disease. In particular, cardiopulmonary or renal diseases accompanied by advanced liver disease can be serious and may determine the quality of life and prognosis of patients. Therefore, both hepatologists and non-hepatologists should pay attention to such abnormalities in the management of patients with liver diseases. PMID:19554648

  10. Abnormal pressure in hydrocarbon environments

    USGS Publications Warehouse

    Law, B.E.; Spencer, C.W.

    1998-01-01

    Abnormal pressures, pressures above or below hydrostatic pressures, occur on all continents in a wide range of geological conditions. According to a survey of published literature on abnormal pressures, compaction disequilibrium and hydrocarbon generation are the two most commonly cited causes of abnormally high pressure in petroleum provinces. In young (Tertiary) deltaic sequences, compaction disequilibrium is the dominant cause of abnormal pressure. In older (pre-Tertiary) lithified rocks, hydrocarbon generation, aquathermal expansion, and tectonics are most often cited as the causes of abnormal pressure. The association of abnormal pressures with hydrocarbon accumulations is statistically significant. Within abnormally pressured reservoirs, empirical evidence indicates that the bulk of economically recoverable oil and gas occurs in reservoirs with pressure gradients less than 0.75 psi/ft (17.4 kPa/m) and there is very little production potential from reservoirs that exceed 0.85 psi/ft (19.6 kPa/m). Abnormally pressured rocks are also commonly associated with unconventional gas accumulations where the pressuring phase is gas of either a thermal or microbial origin. In underpressured, thermally mature rocks, the affected reservoirs have most often experienced a significant cooling history and probably evolved from an originally overpressured system.

  11. Electrocardiograph abnormalities revealed during laparoscopy.

    PubMed

    Nijjer, Sukhjinder; Dubrey, Simon William

    2010-01-01

    This brief case presents a well patient in whom an electrocardiograph abnormality consistent with an accessory pathway was found during a routine procedure. We present the electrocardiographs, explain the underlying condition, and consider why the abnormality was revealed in this manner.

  12. Peripheral nerve: from the microscopic functional unit of the axon to the biomechanically loaded macroscopic structure.

    PubMed

    Topp, Kimberly S; Boyd, Benjamin S

    2012-01-01

    Peripheral nerves are composed of motor and sensory axons, associated ensheathing Schwann cells, and organized layers of connective tissues that are in continuity with the tissues of the central nervous system. Nerve fiber anatomy facilitates conduction of electrical impulses to convey information over a distance, and the length of these polarized cells necessitates regulated axonal transport of organelles and structural proteins for normal cell function. Nerve connective tissues serve a protective function as the limb is subjected to the stresses of myriad limb positions and postures. Thus, the tissues are uniquely arranged to control the local nerve fiber environment and modulate physical stresses. In this brief review, we describe the microscopic anatomy and physiology of peripheral nerve and the biomechanical properties that enable nerve to withstand the physical stresses of everyday life. PMID:22133662

  13. A biomaterials approach to peripheral nerve regeneration: bridging the peripheral nerve gap and enhancing functional recovery

    PubMed Central

    Daly, W.; Yao, L.; Zeugolis, D.; Windebank, A.; Pandit, A.

    2012-01-01

    Microsurgical techniques for the treatment of large peripheral nerve injuries (such as the gold standard autograft) and its main clinically approved alternative—hollow nerve guidance conduits (NGCs)—have a number of limitations that need to be addressed. NGCs, in particular, are limited to treating a relatively short nerve gap (4 cm in length) and are often associated with poor functional recovery. Recent advances in biomaterials and tissue engineering approaches are seeking to overcome the limitations associated with these treatment methods. This review critically discusses the advances in biomaterial-based NGCs, their limitations and where future improvements may be required. Recent developments include the incorporation of topographical guidance features and/or intraluminal structures, which attempt to guide Schwann cell (SC) migration and axonal regrowth towards their distal targets. The use of such strategies requires consideration of the size and distribution of these topographical features, as well as a suitable surface for cell–material interactions. Likewise, cellular and molecular-based therapies are being considered for the creation of a more conductive nerve microenvironment. For example, hurdles associated with the short half-lives and low stability of molecular therapies are being surmounted through the use of controlled delivery systems. Similarly, cells (SCs, stem cells and genetically modified cells) are being delivered with biomaterial matrices in attempts to control their dispersion and to facilitate their incorporation within the host regeneration process. Despite recent advances in peripheral nerve repair, there are a number of key factors that need to be considered in order for these new technologies to reach the clinic. PMID:22090283

  14. Solitary fibrous tumour of the vagus nerve.

    PubMed

    Scholsem, Martin; Scholtes, Felix

    2012-04-01

    We describe the complete removal of a foramen magnum solitary fibrous tumour in a 36-year-old woman. It originated on a caudal vagus nerve rootlet, classically described as the 'cranial' accessory nerve root. This ninth case of immunohistologically confirmed cranial or spinal nerve SFT is the first of the vagus nerve.

  15. Management of traumatic facial nerve injuries.

    PubMed

    Greywoode, Jewel D; Ho, Hao H; Artz, Gregory J; Heffelfinger, Ryan N

    2010-12-01

    Management of facial nerve injuries requires knowledge and skills that should be in every facial plastic surgeon's armamentarium. This article will briefly review the anatomy of the facial nerve, discuss the assessment of facial nerve injury, and describe the management of facial nerve injury after soft tissue trauma. PMID:21086238

  16. Nerve Transfers for the Restoration of Wrist, Finger, and Thumb Extension After High Radial Nerve Injury.

    PubMed

    Pet, Mitchell A; Lipira, Angelo B; Ko, Jason H

    2016-05-01

    High radial nerve injury is a common pattern of peripheral nerve injury most often associated with orthopedic trauma. Nerve transfers to the wrist and finger extensors, often from the median nerve, offer several advantages when compared to nerve repair or grafting and tendon transfer. In this article, we discuss the forearm anatomy pertinent to performing these nerve transfers and review the literature surrounding nerve transfers for wrist, finger, and thumb extension. A suggested algorithm for management of acute traumatic high radial nerve palsy is offered, and our preferred surgical technique for treatment of high radial nerve palsy is provided. PMID:27094891

  17. [Nerve-sparing radical prostatectomy].

    PubMed

    Okada, K; Tada, M; Nakano, A; Konno, T

    1988-04-01

    The neuroanatomy of the pelvic space was studied in order to clarify the course of cavernous nerves responsible for erectile function. The cavernous nerves travel along the dorsolateral portion at the base toward the apex of the prostate, then penetrate urogenital diaphragm at the lateral aspect of the membranous urethra. According to the anatomical findings, nerve-sparing radical prostatectomy was performed through the antegrade approach in 28 patients with prostate cancer. No significant surgical complications were encountered in the present series. Of the 28, evaluable cases were limited to 22 in terms of erection. Fifteen patients (68%) recovered their erectile function after nerve-sparing surgery. Therefore, the present surgical technique seems to be effective for the preservation of male sexual function following radical pelvic surgery.

  18. Schwannomatosis of Cervical Vagus Nerve

    PubMed Central

    Sasi, M. P.

    2016-01-01

    Cervical vagal schwannoma is a rare entity among lesions presenting as a neck mass. They are usually slow-growing benign lesions closely associated with the vagus nerve. They are usually solitary and asymptomatic. Multiple schwannomas occurring in patients without neurofibromatosis (NF) are rare and have recently been referred to as schwannomatosis. Here, we present a case of a neck mass that had imaging features suggestive of vagal schwannoma and was operated upon. Intraoperatively, it was discovered to be a case of multiple vagal cervical schwannoma, all directly related to the right vagus nerve, and could be resected from the nerve in toto preserving the function of the vagus nerve. Final HPR confirmed our pre-op suspicion of vagal schwannomatosis.

  19. Clinical features on nerve gas terrorism in Matsumoto.

    PubMed

    Okudera, Hiroshi

    2002-01-01

    Clinical features on the first unexpected nerve gas terrorism using sarin (isopropyl methylphosphonofluoridate) on citizens in the city of Matsumoto is described. The nerve gas terrorism occurred at midnight on 27 June, 1994. About 600 people including residents and rescue staff were exposed to sarin gas. Fifty-eight victims were admitted to hospitals and seven died. Theoretically, sarin inhibits systemic acetylcholinesterase and damages all the autonomic transmission at the muscarinic and nicotinic acetylcholine receptor. Miosis was the most common finding in the affected people. In cases with severe poisoning, organophosphate may affect the central nervous system and cause cardiomyopathy. A few of the victims complained of arrhythmia and showed a decreased cardiac contraction. Abnormal electroencephalograms were recorded in two patients. The clinical features and follow-up studies are discussed with reference to the Tokyo subway terrorism and related articles.

  20. Isolated optic nerve oedema as unusual presentation of electric injury.

    PubMed

    Izzy, Saef; Deeb, Wissam; Peters, George B; Mitchell, Ann

    2014-10-15

    A 45-year-old man with no significant medical history presented following an electric current injury (380 V). He developed multiple systemic injuries including third degree burns and after 1 week of hospitalisation he reported unilateral visual changes. Examination suggested the presence of optic nerve oedema without evidence of haemorrhage, exudate or vessel abnormality. This was considered to be related to the electric shock. A trial of corticosteroids was considered. He was followed up to 5 months in clinic and was noted to have developed unilateral optic atrophy and no other systemic manifestations. Initial and 5 months follow-up optic nerve colour photograph and optical coherence topography were documented. The present case highlights the fact that electric current injury can present with only a unilateral ischaemic optic neuropathy, the need for early diagnosis for timely treatment and the controversial role of corticosteroids.

  1. High Frequency Sacral Root Nerve Block Allows Bladder Voiding

    PubMed Central

    Boger, Adam S.; Bhadra, Narendra; Gustafson, Kenneth J

    2013-01-01

    1) Aims Dyssynergic reflexive external urethral sphincter (EUS) activity following spinal cord injury can prevent bladder voiding, resulting in significant medical complications. Irreversible sphincterotomies or neurotomies can prevent EUS activation and allow bladder voiding, but may cause incontinence or loss of sacral reflexes. We investigated whether kilohertz frequency (KF) electrical conduction block of the sacral roots could prevent EUS activation and allow bladder voiding. 2) Methods The S2 sacral nerve roots were stimulated bilaterally to generate bladder pressure in 6 cats. One S1 nerve root was stimulated proximally (20 Hz biphasic pulse trains) to evoke EUS pressure, simulating worst-case dyssynergic EUS reflexes. KF waveforms (12.5 kHz biphasic square wave) applied to an electrode implanted distally on the S1 nerve root blocked nerve conduction, preventing the increase in EUS pressure and allowing voiding. 3) Results Applying KF waveforms increased bladder voiding in single, limited-duration trials from 3 ± 6% to 59 ± 12%. Voiding could be increased to 82 ± 9% of the initial bladder volume by repeating or increasing the duration of the trials. 4) Conclusions Sacral nerve block can prevent EUS activation and allow complete bladder voiding, potentially eliminating the need for a neurotomy. Eliminating neurotomy requirements could increase patient acceptance of bladder voiding neuroprostheses, increasing patient quality of life and reducing the cost of patient care. PMID:22473837

  2. Stimulation of the human auditory nerve with optical radiation

    NASA Astrophysics Data System (ADS)

    Fishman, Andrew; Winkler, Piotr; Mierzwinski, Jozef; Beuth, Wojciech; Izzo Matic, Agnella; Siedlecki, Zygmunt; Teudt, Ingo; Maier, Hannes; Richter, Claus-Peter

    2009-02-01

    A novel, spatially selective method to stimulate cranial nerves has been proposed: contact free stimulation with optical radiation. The radiation source is an infrared pulsed laser. The Case Report is the first report ever that shows that optical stimulation of the auditory nerve is possible in the human. The ethical approach to conduct any measurements or tests in humans requires efficacy and safety studies in animals, which have been conducted in gerbils. This report represents the first step in a translational research project to initiate a paradigm shift in neural interfaces. A patient was selected who required surgical removal of a large meningioma angiomatum WHO I by a planned transcochlear approach. Prior to cochlear ablation by drilling and subsequent tumor resection, the cochlear nerve was stimulated with a pulsed infrared laser at low radiation energies. Stimulation with optical radiation evoked compound action potentials from the human auditory nerve. Stimulation of the auditory nerve with infrared laser pulses is possible in the human inner ear. The finding is an important step for translating results from animal experiments to human and furthers the development of a novel interface that uses optical radiation to stimulate neurons. Additional measurements are required to optimize the stimulation parameters.

  3. Mechanisms of trigeminal nerve injuries.

    PubMed

    Ziccardi, V B; Assael, L A

    2001-09-01

    Injuries to the trigeminal nerve branches are a known and accepted risk in oral and maxillofacial surgery. It is prudent for the practitioner to explain the risks to patients as part of the informed consent process and to recognize and document the presence of nerve injury postoperatively. Patients should be referred to a surgeon experienced in microsurgical techniques in a timely fashion for evaluation and possible surgical intervention if an injury is not resolving.

  4. Identifying the Non-recurrent Laryngeal Nerve: Preventing a Major Risk of Morbidity During Thyroidectomy

    PubMed Central

    Mahmodlou, Rahim; Aghasi, Mohammad Reza; Sepehrvand, Nariman

    2013-01-01

    Non-recurrent laryngeal nerve (NRLN) is a rare anomaly which is reported in 0.3%-0.8% of people on the right side and in 0.004% (extremely rare) on the left side. Damage to this nerve during the surgical procedure may lead to severe iatrogenic morbidity and should therefore be prevented from being damaged. The best way to avoid this damage to the nerve is to identify the nerve with a systematic diligent dissection based on usual anatomical landmarks and awareness about the possibility of their existence. Hereby, we are going to present a 26-year-old woman, a case of NRLN on the right side which was identified during thyroidectomy. The nervous anomaly was accompanied with vascular abnormality which was confirmed by computerized tomography (CT) angiography, post-operatively. PMID:23543847

  5. Abnormalities of the blink reflex in burning mouth syndrome.

    PubMed

    Jääskeläinen, S K; Forssell, H; Tenovuo, O

    1997-12-01

    To our knowledge, this is the first report on pain-related abnormalities of the eye blink reflex (BR) in a clinical pain patient population. The objective of this study was to evaluate the possible neuropathic mechanisms underlying the burning mouth syndrome (BMS), by means of objective electrophysiological examination of the trigemino-facial system. We studied the BR with stimulation of the supraorbital nerve (SON) with particular emphasis on the occurrence of the pain-related ultralate R3 components, and the habituation response of the R2 components. The subjects consisted of eleven BMS patients and 10 healthy control subjects. All patients underwent thorough clinical oral and neurological examinations. The motor function of the trigeminal nerve was assessed with a jaw reflex recording, and a needle-EMG examination of the facial and masticatory muscles was performed in the patients with abnormalities in the BR recordings. The jaw reflexes, the latencies of the BR components, and the needle-EMG examinations were normal in all patients. As a group, the BMS patients had statistically significantly higher stimulus thresholds for the tactile R 1 components of the BR compared with the control subjects. With non-noxious stimulation, the BMS patients showed more frequently pain-related R3 components (11/22 SONs) compared with the controls (3/20 SONs). In addition, four BMS patients had abnormal habituation of the R2 components. In two of these patients, the findings were segmental (i.e., unilateral), coinciding with the side of the subjective BM symptoms. The abnormalities of the BR tests appeared to be related to longer disease duration. Our results suggest a possible pathologic involvement of the nervous system in chronic BMS.

  6. [Bilateral reversed palmaris longus muscle--a rare cause of peripheral median nerve compression syndrome. Case report].

    PubMed

    Giunta, R; Brunner, U; Wilhelm, K

    1993-10-01

    A rare case of median nerve compression syndrome outside the carpal tunnel in the distal forearm is reported. A 21-year-old man suffered while working from symptoms of temporary median nerve compression in both forearms; this was caused by hypertrophy of reversed palmaris longus muscles. Resection of the abnormal muscle bellies relieved the symptoms immediately. Only ten similar cases have been reported in the literature, and this is the first case with bilateral symptoms.

  7. [Peripheral Nerve Injuries in Sports].

    PubMed

    Tettenborn, B; Mehnert, S; Reuter, I

    2016-09-01

    Peripheral nerve injuries due to sports are relatively rare but the exact incidence is not known due to a lack of epidemiological studies. Particular sports activities tend to cause certain peripheral nerve injuries including direct acute compression or stretching, repetitive compression and stretching over time, or another mechanism such as ischemia or laceration. These nerve lesions may be severe and delay or preclude the athlete's return to sports, especially in cases with delayed diagnosis. Repetitive and vigorous use or overuse makes the athlete vulnerable to disorders of the peripheral nerves, and sports equipment may cause compression of the nerves. Depending on etiology, the treatment is primarily conservative and includes physiotherapy, modification of movements and sports equipment, shoe inserts, splinting, antiphlogistic drugs, sometimes local administration of glucocorticoids or, lately, the use of extracorporeal shock waves. Most often, cessation of the offending physical activity is necessary. Surgery is only indicated in the rare cases of direct traumatic nerve injury or when symptoms are refractory to conservative therapy. Prognosis mainly depends on the etiology and the available options of modifying measures.This article is based on the publications "Reuter I, Mehnert S. Engpasssyndrome peripherer Nerven bei Sportlern". Akt Neurol 2012;39:292-308 and Sportverl Sportschad 2013;27:130-146. PMID:27607069

  8. Noninvasive imaging of peripheral nerves.

    PubMed

    Rangavajla, Gautam; Mokarram, Nassir; Masoodzadehgan, Nazanin; Pai, S Balakrishna; Bellamkonda, Ravi V

    2014-01-01

    Recent developments in the field of peripheral nerve imaging extend the capabilities of imaging modalities to assist in the diagnosis and treatment of patients with peripheral nerve maladies. Methods such as magnetic resonance imaging (MRI) and its derivative diffusion tensor imaging (DTI), ultrasound (US) and positron emission tomography (PET) are capable of assessing nerve structure and function following injury and relating the state of the nerve to electrophysiological and histological analysis. Of the imaging methods surveyed here, each offered unique and interesting advantages related to the field. MRI offered the opportunity to visualize immune activity on the injured nerve throughout the course of the regeneration process, and DTI offered numerical characterization of the injury and the ability to develop statistical bases for diagnosing injury. US extends imaging to the treatment phase by enabling more precise analgesic applications following surgery, and PET represents a novel method of assessing nerve injury through analysis of relative metabolism rates in injured and healthy tissue. Exciting new possibilities to enhance and extend the abilities of imaging methods are also discussed, including innovative contrast agents, some of which enable multimodal imaging approaches and present opportunities for treatment application. PMID:25766202

  9. Chromosomal abnormalities in human sperm

    SciTech Connect

    Martin, R.H.

    1985-01-01

    The ability to analyze human sperm chromosome complements after penetration of zona pellucida-free hamster eggs provides the first opportunity to study the frequency and type of chromosomal abnormalities in human gametes. Two large-scale studies have provided information on normal men. We have studied 1,426 sperm complements from 45 normal men and found an abnormality rate of 8.9%. Brandriff et al. (5) found 8.1% abnormal complements in 909 sperm from 4 men. The distribution of numerical and structural abnormalities was markedly dissimilar in the 2 studies. The frequency of aneuploidy was 5% in our sample and only 1.6% in Brandriff's, perhaps reflecting individual variability among donors. The frequency of 24,YY sperm was low: 0/1,426 and 1/909. This suggests that the estimates of nondisjunction based on fluorescent Y body data (1% to 5%) are not accurate. We have also studied men at increased risk of sperm chromosomal abnormalities. The frequency of chromosomally unbalanced sperm in 6 men heterozygous for structural abnormalities varied dramatically: 77% for t11;22, 32% for t6;14, 19% for t5;18, 13% for t14;21, and 0% for inv 3 and 7. We have also studied 13 cancer patients before and after radiotherapy and demonstrated a significant dose-dependent increase of sperm chromosome abnormalities (numerical and structural) 36 months after radiation treatment.

  10. MICROCHIP ENZYMATIC ASSAY OF ORGANOPHOSPHATE NERVE AGENTS. (R830900)

    EPA Science Inventory

    An on-chip enzymatic assay for screening organophosphate (OP) nerve agents, based on a pre-column reaction of organophosphorus hydrolase (OPH), electrophoretic separation of the phosphonic acid products, and their contactless-conductivity detection, is described. Factors affec...

  11. Mechanisms defining the electrotonic potential abnormalities in simulated amyotrophic lateral sclerosis.

    PubMed

    Stephanova, D I; Krustev, S M; Negrev, N

    2012-06-01

    Electrotonic potentials allow the accommodative processes to polarizing stimuli to be assessed. Electrotonic potential transients in response to applied polarizing stimuli are caused by the kinetics of underlying axonal conductances. Here, we study these transients using our multi-layered model of the human motor nerve, in three simulated cases of the motor neuron disease amyotrophic lateral sclerosis (ALS): ALS1, ALS2 and ALS3 are three consecutively greater degrees of uniform axonal dysfunctions along the human motor nerve fibre. The results show that the responses in the ALS1 case are quite similar to the normal case. In contrast, in the ALS2 and ALS3 cases, long-lasting (100 ms) subthreshold depolarizing stimuli activate the classical "transient" Na(+) channels in the nodal and in the internodal axolemma beneath the myelin sheath; this leads to action potential generation during the early parts of the electrotonic responses in all compartments along the fibre length. The results also show that the electrotonic potentials in response to long-lasting (100 ms) subthreshold hyperpolarizing stimuli in the ALS1 and ALS2 cases are quiet similar to those of the normal case. However, the current kinetics in the ALS3 case differs from the normal case after the termination of the long-lasting hyperpolarizing stimuli. In the most abnormal ALS3 case, the activation of the Na(+) channels in the nodal and in the internodal axolemma leads to repetitive action potential generation in the late parts (100-200 ms) of the hyperpolarizing electrotonic responses. The results show that the repetitive firing, due to the progressively increased nodal and internodal ion channel dysfunction, are consistent with the loss of functional potassium channels involving both the fast and the slow potassium channel types. The results confirm that the electrotonic potentials in the three simulated ALS cases are specific indicators for the motor neuron disease ALS. The mechanisms underlying the

  12. Equine laryngeal hemiplegia. Part III. A teased fibre study of peripheral nerves.

    PubMed

    Cahill, J I; Goulden, B E

    1986-11-01

    Individual nerve fibres were isolated from the recurrent laryngeal and some distal hindlimb nerves, in an investigation of equine laryngeal hemiplegia. One hundred teased fibres were obtained from each of three sampling sites on both left and right recurrent laryngeal nerves, from 15 Thoroughbred horses. These fibres were graded descriptively and internode lengths measured. A distal distribution of pathology was demonstrated in all groups studied, but was most severe in the clinical group of horses. The predominant change was one of short thinly myelinated internodes interspersed amongst normally myelinated internodes, indicating remyelination of previously demyelinated areas of nerve fibre. Such pathological change was also reflected by the decreased mean internode length, and its increased variability associated with disease. However, it was determined statistically that these abnormal internodes were grouped along particular nerve fibres, rather than being randomly distributed between all nerve fibres. This is thought to indicate myelin sheath changes secondary to underlying axonal pathology. Thus it was concluded that the primary pathology was likely to be axonal in nature, while the high incidence of demyelination changes was a reflection of the chronic nature of the disease process. Thus, the distal distribution of pathology, the primary axonal involvement, the presence of changes in left and right recurrent laryngeal and distal limb nerves, all support the classification of equine laryngeal hemiplegia as a distal axonopathy.

  13. Nerves as embodied metaphor in the Canada/Mexico seasonal agricultural workers program.

    PubMed

    Mysyk, Avis; England, Margaret; Gallegos, Juan Arturo Avila

    2008-01-01

    This article examines nerves among participants in the Canada/Mexico Seasonal Agricultural Workers Program (C/MSAWP). Based on in-depth interviews with 30 Mexican farm workers in southwestern Ontario, we demonstrate that nerves embodies the distress of economic need, relative powerlessness, and the contradictions inherent in the C/MSAWP that result in various life's lesions. We also explore their use of the nerves idiom as an embodied metaphor for their awareness of the breakdown in self/society relations and, in certain cases, of the lack of control over even themselves. This article contributes to that body of literature that locates nerves at the "normal" end of the "normal/abnormal" continuum of popular illness categories because, despite the similarities in symptoms of nerves among Mexican farm workers and those of anxiety and/or mood disorders, medicalization has not occurred. If nerves has not been medicalized among Mexican farm workers, neither has it given rise to resistance to their relative powerlessness as migrant farm workers. Nonetheless, nerves does serve as an effective vehicle for expressing their distress within the context of the C/MSAWP.

  14. Nerves as embodied metaphor in the Canada/Mexico seasonal agricultural workers program.

    PubMed

    Mysyk, Avis; England, Margaret; Gallegos, Juan Arturo Avila

    2008-01-01

    This article examines nerves among participants in the Canada/Mexico Seasonal Agricultural Workers Program (C/MSAWP). Based on in-depth interviews with 30 Mexican farm workers in southwestern Ontario, we demonstrate that nerves embodies the distress of economic need, relative powerlessness, and the contradictions inherent in the C/MSAWP that result in various life's lesions. We also explore their use of the nerves idiom as an embodied metaphor for their awareness of the breakdown in self/society relations and, in certain cases, of the lack of control over even themselves. This article contributes to that body of literature that locates nerves at the "normal" end of the "normal/abnormal" continuum of popular illness categories because, despite the similarities in symptoms of nerves among Mexican farm workers and those of anxiety and/or mood disorders, medicalization has not occurred. If nerves has not been medicalized among Mexican farm workers, neither has it given rise to resistance to their relative powerlessness as migrant farm workers. Nonetheless, nerves does serve as an effective vehicle for expressing their distress within the context of the C/MSAWP. PMID:18958786

  15. Contactin orchestrates assembly of the septate-like junctions at the paranode in myelinated peripheral nerve.

    PubMed

    Boyle, M E; Berglund, E O; Murai, K K; Weber, L; Peles, E; Ranscht, B

    2001-05-01

    Rapid nerve impulse conduction depends on specialized membrane domains in myelinated nerve, the node of Ranvier, the paranode, and the myelinated internodal region. We report that GPI-linked contactin enables the formation of the paranodal septate-like axo-glial junctions in myelinated peripheral nerve. Contactin clusters at the paranodal axolemma during Schwann cell myelination. Ablation of contactin in mutant mice disrupts junctional attachment at the paranode and reduces nerve conduction velocity 3-fold. The mutation impedes intracellular transport and surface expression of Caspr and leaves NF155 on apposing paranodal myelin disengaged. The contactin mutation does not affect sodium channel clustering at the nodes of Ranvier but alters the location of the Shaker-type Kv1.1 and Kv1.2 potassium channels. Thus, contactin is a crucial part in the machinery that controls junctional attachment at the paranode and ultimately the physiology of myelinated nerve. PMID:11395001

  16. [Methodological considerations concerning peripheral nerve morphometry].

    PubMed

    Cuadras, J; Butí, M; Calvet, S; Verdú, E; Navarro, X

    1995-01-01

    Morphometric studies of the peripheral nerve often present widely varying results which, in part at least, may be attributed to the different methodologies used. Two questions may be of importance with regard to the reliability of such results: the preselection of fibres according to their morphology and the method used in quantifying observations. In this work a morphological study was carried out on the myelinated fibres of the sciatic nerve of a rat in order to evaluate fibre selection criteria. A morphometric analysis was also performed using manual measurements, image digitalisation and surveying, and automatic image analysis. It was shown that morphological variability of transverse section fibres is considerable and that, really, the proportion of circular fibres with homogeneous compact myelin is only 50 to 70%, from which we can conclude that the selection of fibres carried out in some studies wishing to eliminate abnormal fibres is somewhat exaggerated. By analysing the fibres using various methods significant differences appear, some due to the fact that distinct methods may be used to calculate the same parameters in a different way. The most reliable parameters would appear to be those which do not depend on the shape of the fibres and those which automatic or semiautomatic methods can calculate directly such as areas and perimeters. In any case quantifying methods seem hardly discriminatory and the differences between methods disappear if analyses are carried out using random samples. Preselection of fibres appears unnecessary in this context as in no case are the results altered. Finally we suggest finishing quantitative analyses with qualitative studies which would permit getting more information especially useful in cases of ageing, regeneration or pathological studies. PMID:8597982

  17. Malignant Peripheral Nerve Sheath Tumor -A Rare Malignancy in Mandible.

    PubMed

    Majumdar, Sumit; Kotina, Sreekanth; Mahesh, Nirujogi; Uppala, Divya; Kumar, Singam Praveen

    2016-06-01

    Malignant Peripheral Nerve Sheath Tumor (MPNST) is biologically an aggressive tumor that is usually found in the extremities, trunk and infrequently found in the head and neck area particularly in the jaws, arising from the cells allied with nerve sheath. Mandibular MPNST may either arise from a preexisting neurofibroma or develop de novo. Because of the greater variability from case to case in overall appearance both clinically and histologically, a case of MPNST of the mandible in a 25-year-old female patient is reported. The lesion was excised and immunohistological studies (S-100 & Neuron specific enolase) were conducted to confirm the neural origin.

  18. Malignant Peripheral Nerve Sheath Tumor -A Rare Malignancy in Mandible

    PubMed Central

    Majumdar, Sumit; Kotina, Sreekanth; Uppala, Divya; Kumar, Singam Praveen

    2016-01-01

    Malignant Peripheral Nerve Sheath Tumor (MPNST) is biologically an aggressive tumor that is usually found in the extremities, trunk and infrequently found in the head and neck area particularly in the jaws, arising from the cells allied with nerve sheath. Mandibular MPNST may either arise from a preexisting neurofibroma or develop de novo. Because of the greater variability from case to case in overall appearance both clinically and histologically, a case of MPNST of the mandible in a 25-year-old female patient is reported. The lesion was excised and immunohistological studies (S-100 & Neuron specific enolase) were conducted to confirm the neural origin. PMID:27504425

  19. Diabetic neuropathy increases stimulation threshold during popliteal sciatic nerve block†

    PubMed Central

    Heschl, S.; Hallmann, B.; Zilke, T.; Gemes, G.; Schoerghuber, M.; Auer-Grumbach, M.; Quehenberger, F.; Lirk, P.; Hogan, Q.; Rigaud, M.

    2016-01-01

    Background Peripheral nerve stimulation is commonly used for nerve localization in regional anaesthesia, but recommended stimulation currents of 0.3–0.5 mA do not reliably produce motor activity in the absence of intraneural needle placement. As this may be particularly true in patients with diabetic neuropathy, we examined the stimulation threshold in patients with and without diabetes. Methods Preoperative evaluation included a neurological exam and electroneurography. During ultrasound-guided popliteal sciatic nerve block, we measured the current required to produce motor activity for the tibial and common peroneal nerve in diabetic and non-diabetic patients. Proximity to the nerve was evaluated post-hoc using ultrasound imaging. Results Average stimulation currents did not differ between diabetic (n=55) and non-diabetic patients (n=52). Although the planned number of patients was not reached, the power goal for the mean stimulation current was met. Subjects with diminished pressure perception showed increased thresholds for the common peroneal nerve (median 1.30 vs. 0.57 mA in subjects with normal perception, P=0.042), as did subjects with decreased pain sensation (1.60 vs. 0.50 mA in subjects with normal sensation, P=0.038). Slowed ulnar nerve conduction velocity predicted elevated mean stimulation current (r=−0.35, P=0.002). Finally, 15 diabetic patients required more than 0.5 mA to evoke a motor response, despite intraneural needle placement (n=4), or required currents ≥2 mA despite needle-nerve contact, vs three such patients (1 intraneural, 2 with ≥2 mA) among non-diabetic patients (P=0.003). Conclusions These findings suggest that stimulation thresholds of 0.3–0.5 mA may not reliably determine close needle-nerve contact during popliteal sciatic nerve block, particularly in patients with diabetic neuropathy. Clinical trial registration NCT01488474 PMID:26994231

  20. Laminin-based Nanomaterials for Peripheral Nerve Tissue Engineering

    NASA Astrophysics Data System (ADS)

    Neal, Rebekah Anne

    supported by nerve conduction studies and electromyography which described impulse transmission, muscle stimulation, and foot twitch through the region of regeneration. These studies provide a firm foundation for the use of natural-synthetic blend electrospun nanofibers to enhance existing hollow nerve guidance conduits. The similarity in surgical technique and obvious benefit to the patient should lead to rapid translation into clinical application.

  1. Cranial Nerves IX, X, XI, and XII

    PubMed Central

    Sanders, Richard D.

    2010-01-01

    This article concludes the series on cranial nerves, with review of the final four (IX–XII). To summarize briefly, the most important and common syndrome caused by a disorder of the glossopharyngeal nerve (craniel nerve IX) is glossopharyngeal neuralgia. Also, swallowing function occasionally is compromised in a rare but disabling form of tardive dyskinesia called tardive dystonia, because the upper motor portion of the glossopharyngel nerve projects to the basal ganglia and can be affected by lesions in the basal ganglia. Vagus nerve funtion (craniel nerve X) can be compromised in schizophrenia, bulimia, obesity, and major depression. A cervical lesion to the nerve roots of the spinal accessory nerve (craniel nerve XI) can cause a cervical dystonia, which sometimes is misdiagnosed as a dyskinesia related to neuroleptic use. Finally, unilateral hypoglossal (craniel nerve XII) nerve palsy is one of the most common mononeuropathies caused by brain metastases. Supranuclear lesions of cranial nerve XII are involved in pseudobulbar palsy and ALS, and lower motor neuron lesions of cranial nerve XII can also be present in bulbar palsy and in ALS patients who also have lower motor neuron involvement. This article reviews these and other syndromes related to cranial nerves IX through XII that might be seen by psychiatry. PMID:20532157

  2. Detection of optic nerve damage in ocular hypertension.

    PubMed Central

    Ross, J E; Bron, A J; Reeves, B C; Emmerson, P G

    1985-01-01

    Thirty patients with ocular hypertension were tested for contrast sensitivity loss. Seventeen were not on treatment, and thirteen were receiving some form of pressure reducing therapy. The contrast sensitivity results of 63% of ocular hypertensive eyes were abnormal (greater than 2 SDs from the age matched norm). Thus it appears that contrast sensitivity can detect early visual loss in patients who have normal visual fields and it is suggested that this test might be used as a criterion for therapy in ocular hypertension. There was no significant difference in the intraocular pressures between patients who gave abnormal contrast sensitivity results and those who did not in the untreated group (p greater than 0.05), suggesting that intraocular pressure level is a poor predictor of optic nerve fibre damage in patients with ocular hypertension. PMID:4084481

  3. Polylactic-co-glycolic acid microspheres containing three neurotrophic factors promote sciatic nerve repair after injury

    PubMed Central

    Zhao, Qun; Li, Zhi-yue; Zhang, Ze-peng; Mo, Zhou-yun; Chen, Shi-jie; Xiang, Si-yu; Zhang, Qing-shan; Xue, Min

    2015-01-01

    A variety of neurotrophic factors have been shown to repair the damaged peripheral nerve. However, in clinical practice, nerve growth factor, neurotrophin-3 and brain-derived neurotrophic factor are all peptides or proteins that may be rapidly deactivated at the focal injury site; their local effective concentration time following a single medication cannot meet the required time for spinal axons to regenerate and cross the glial scar. In this study, we produced polymer sustained-release microspheres based on the polylactic-co-glycolic acid copolymer; the microspheres at 300-μm diameter contained nerve growth factor, neurotrophin-3 and brain-derived neurotrophic factor. Six microspheres were longitudinally implanted into the sciatic nerve at the anastomosis site, serving as the experimental group; while the sciatic nerve in the control group was subjected to the end-to-end anastomosis using 10/0 suture thread. At 6 weeks after implantation, the lower limb activity, weight of triceps surae muscle, sciatic nerve conduction velocity and the maximum amplitude were obviously better in the experimental group than in the control group. Compared with the control group, more regenerating nerve fibers were observed and distributed in a dense and ordered manner with thicker myelin sheaths in the experimental group. More angiogenesis was also visible. Experimental findings indicate that polylactic-co-glycolic acid composite microspheres containing nerve growth factor, neurotrophin-3 and brain-derived neurotrophic factor can promote the restoration of sciatic nerve in rats after injury. PMID:26604912

  4. Improved peripheral nerve regeneration in streptozotocin-induced diabetic rats by oral lumbrokinase.

    PubMed

    Lee, Han-Chung; Hsu, Yuan-Man; Tsai, Chin-Chuan; Ke, Cherng-Jyh; Yao, Chun-Hsu; Chen, Yueh-Sheng

    2015-01-01

    We assessed the therapeutic effects of lumbrokinase, a group of enzymes extracted from the earthworm, on peripheral-nerve regeneration using well-defined sciatic nerve lesion paradigms in diabetic rats induced by the injection of streptozotocin (STZ). We found that lumbrokinase therapy could improve the rats' circulatory blood flow and promote the regeneration of axons in a silicone rubber conduit after nerve transection. Lumbrokinase treatment could also improve the neuromuscular functions with better nerve conductive performances. Immunohistochemical staining showed that lumbrokinase could dramatically promote calcitonin gene-related peptide (CGRP) expression in the lamina I-II regions in the dorsal horn ipsilateral to the injury and cause a marked increase in the number of macrophages recruited within the distal nerve stumps. In addition, the lumbrokinase could stimulate the secretion of interleukin-1 (IL-1), nerve growth factor (NGF), platelet-derived growth factor (PDGF), and transforming growth factor-β (TGF-β) in dissected diabetic sciatic nerve segments. In conclusion, the administration of lumbrokinase after nerve repair surgery in diabetic rats was found to have remarkable effects on promoting peripheral nerve regeneration and functional recovery. PMID:25787300

  5. Identification of Changes in Gene expression of rats after Sensory and Motor Nerves Injury.

    PubMed

    Wang, Yu; Guo, Zhi-Yuan; Sun, Xun; Lu, Shi-Bi; Xu, Wen-Jing; Zhao, Qing; Peng, Jiang

    2016-01-01

    Wallerian degeneration is a sequence of events in the distal stump of axotomized nerves. Despite large numbers of researches concentrating on WD, the biological mechanism still remains unclear. Hence we constructed a rat model with both motor and sensory nerves injury and then conducted a RNA-seq analysis. Here the rats were divided into the 4 following groups: normal motor nerves (NMN), injured motor nerves (IMN), normal sensory nerves (NSN) and injured sensory nerves (ISN). The transcriptomes of rats were sequenced by the Illumina HiSeq. The differentially expressed genes (DEGs) of 4 combinations including NMN vs. IMN, NSN vs. ISN, NMN vs. NSN and IMN vs. ISN were identified respectively. For the above 4 combinations, we identified 1666, 1514, 95 and 17 DEGs. We found that NMN vs. IMN shared the most common genes with NSN vs. ISN indicating common mechanisms between motor nerves injury and sensory nerves injury. At last, we performed an enrichment analysis and observed that the DEGs of NMN vs IMN and NSN vs. ISN were significantly associated with binding and activity, immune response, biosynthesis, metabolism and development. We hope our study may shed light on the molecular mechanisms of nerves degeneration and regeneration during WD.

  6. Identification of Changes in Gene expression of rats after Sensory and Motor Nerves Injury.

    PubMed

    Wang, Yu; Guo, Zhi-Yuan; Sun, Xun; Lu, Shi-Bi; Xu, Wen-Jing; Zhao, Qing; Peng, Jiang

    2016-01-01

    Wallerian degeneration is a sequence of events in the distal stump of axotomized nerves. Despite large numbers of researches concentrating on WD, the biological mechanism still remains unclear. Hence we constructed a rat model with both motor and sensory nerves injury and then conducted a RNA-seq analysis. Here the rats were divided into the 4 following groups: normal motor nerves (NMN), injured motor nerves (IMN), normal sensory nerves (NSN) and injured sensory nerves (ISN). The transcriptomes of rats were sequenced by the Illumina HiSeq. The differentially expressed genes (DEGs) of 4 combinations including NMN vs. IMN, NSN vs. ISN, NMN vs. NSN and IMN vs. ISN were identified respectively. For the above 4 combinations, we identified 1666, 1514, 95 and 17 DEGs. We found that NMN vs. IMN shared the most common genes with NSN vs. ISN indicating common mechanisms between motor nerves injury and sensory nerves injury. At last, we performed an enrichment analysis and observed that the DEGs of NMN vs IMN and NSN vs. ISN were significantly associated with binding and activity, immune response, biosynthesis, metabolism and development. We hope our study may shed light on the molecular mechanisms of nerves degeneration and regeneration during WD. PMID:27253193

  7. Polylactic-co-glycolic acid microspheres containing three neurotrophic factors promote sciatic nerve repair after injury.

    PubMed

    Zhao, Qun; Li, Zhi-Yue; Zhang, Ze-Peng; Mo, Zhou-Yun; Chen, Shi-Jie; Xiang, Si-Yu; Zhang, Qing-Shan; Xue, Min

    2015-09-01

    A variety of neurotrophic factors have been shown to repair the damaged peripheral nerve. However, in clinical practice, nerve growth factor, neurotrophin-3 and brain-derived neurotrophic factor are all peptides or proteins that may be rapidly deactivated at the focal injury site; their local effective concentration time following a single medication cannot meet the required time for spinal axons to regenerate and cross the glial scar. In this study, we produced polymer sustained-release microspheres based on the polylactic-co-glycolic acid copolymer; the microspheres at 300-μm diameter contained nerve growth factor, neurotrophin-3 and brain-derived neurotrophic factor. Six microspheres were longitudinally implanted into the sciatic nerve at the anastomosis site, serving as the experimental group; while the sciatic nerve in the control group was subjected to the end-to-end anastomosis using 10/0 suture thread. At 6 weeks after implantation, the lower limb activity, weight of triceps surae muscle, sciatic nerve conduction velocity and the maximum amplitude were obviously better in the experimental group than in the control group. Compared with the control group, more regenerating nerve fibers were observed and distributed in a dense and ordered manner with thicker myelin sheaths in the experimental group. More angiogenesis was also visible. Experimental findings indicate that polylactic-co-glycolic acid composite microspheres containing nerve growth factor, neurotrophin-3 and brain-derived neurotrophic factor can promote the restoration of sciatic nerve in rats after injury.

  8. Rehabilitation of the trigeminal nerve

    PubMed Central

    Iro, Heinrich; Bumm, Klaus; Waldfahrer, Frank

    2005-01-01

    When it comes to restoring impaired neural function by means of surgical reconstruction, sensory nerves have always been in the role of the neglected child when compared with motor nerves. Especially in the head and neck area, with its either sensory, motor or mixed cranial nerves, an impaired sensory function can cause severe medical conditions. When performing surgery in the head and neck area, sustaining neural function must not only be highest priority for motor but also for sensory nerves. In cases with obvious neural damage to sensory nerves, an immediate neural repair, if necessary with neural interposition grafts, is desirable. Also in cases with traumatic trigeminal damage, an immediate neural repair ought to be considered, especially since reconstructive measures at a later time mostly require for interposition grafts. In terms of the trigeminal neuralgia, commonly thought to arise from neurovascular brainstem compression, a pharmaceutical treatment is considered as the state of the art in terms of conservative therapy. A neurovascular decompression of the trigeminal root can be an alternative in some cases when surgical treatment is sought after. Besides the above mentioned therapeutic options, alternative treatments are available. PMID:22073060

  9. Retinal and optic nerve diseases.

    PubMed

    Margalit, Eyal; Sadda, Srinivas R

    2003-11-01

    A variety of disease processes can affect the retina and/or the optic nerve, including vascular or ischemic disease, inflammatory or infectious disease, and degenerative disease. These disease processes may selectively damage certain parts of the retina or optic nerve, and the specific areas that are damaged may have implications for the design of potential therapeutic visual prosthetic devices. Outer retinal diseases include age-related macular degeneration, pathologic myopia, and retinitis pigmentosa. Although the retinal photoreceptors may be lost, the inner retina is relatively well-preserved in these diseases and may be a target for retinal prosthetic devices. Inner retinal diseases include retinal vascular diseases such as diabetic retinopathy, retinal venous occlusive disease, and retinopathy of prematurity. Other retinal diseases such as ocular infections (retinitis, endophthalmitis) may affect all retinal layers. Because the inner retinal cells, including the retinal ganglion cells, may be destroyed in these diseases (inner retinal or whole retinal), prosthetic devices that stimulate the inner retina may not be effective. Common optic nerve diseases include glaucoma, optic neuritis, and ischemic optic neuropathy. Because the ganglion cell nerve fibers themselves are damaged, visual prosthetics for these diseases will need to target more distal portions of the visual pathway, such as the visual cortex. Clearly, a sound understanding of retinal and optic nerve disease pathophysiology is critical for designing and choosing the optimal visual prosthetic device.

  10. Biomechanical Properties of Recurrent Laryngeal Nerve in the Piglet

    PubMed Central

    Alexander, Megan J.; Barkmeier-Kraemer, Julie M.; Vande Geest, Jonathan P.

    2016-01-01

    Unilateral vocal fold paralysis (UVP) results from damage to the recurrent laryngeal nerve (RLN). The most common causes of UVP are associated with compromised RLN tissue. The purpose of this research was to investigate the biomechanical properties of piglet RLN and identify differences in these properties along its length and in between the left and right side. Quasi-static uniaxial tensile testing and isotropic constitutive modeling was performed on seven piglet RLNs. Stiffness and other biomechanical parameters were derived from these tests and compared from conducting two different statistical analysis for the between and within nerve comparisons. Results showed higher stiffness values in the left RLN segment than for the right. Descriptive data demonstrated a higher stiffness in RLN segments surrounding the aortic arch, indicating a more protective role of the extracellular matrix in these nerves. This research offers insight regarding the protective function of the RLN connective tissues and structural compromise due to its environment. PMID:20369296

  11. Sympathetic sprouting near sensory neurons after nerve injury occurs preferentially on spontaneously active cells and is reduced by early nerve block

    PubMed Central

    Xie, Wenrui; Strong, Judith Ann; Li, Huiqing; Zhang, Jun-Ming

    2006-01-01

    Some chronic pain conditions are maintained or enhanced by sympathetic activity. In animal models of pathological pain, abnormal sprouting of sympathetic fibers around large- and medium-size sensory neurons is observed in dorsal root ganglia (DRG). Large and medium size cells are also more likely to be spontaneously active, suggesting that sprouting may be related to neuron activity. We previously showed that sprouting could be reduced by systemic or locally applied lidocaine. In the complete sciatic nerve transection model in rats, spontaneous activity initially originates in the injury site; later, the DRG become the major source of spontaneous activity. In this study, spontaneous activity reaching the DRG soma was reduced by early nerve blockade (local perfusion of the transected nerve with TTX for the first 7 days after injury). This significantly reduced sympathetic sprouting. Conversely, increasing spontaneous activity by local nerve perfusion with K+ channel blockers increased sprouting. The hyperexcitability and spontaneous activity of DRG neurons observed in this model were also significantly reduced by early nerve blockade. These effects of early nerve blockade on sprouting, excitability, and spontaneous activity were all observed 4 to 5 weeks after the end of early nerve blockade, indicating that the early period of spontaneous activity in the injured nerve is critical for establishing the more long-lasting pathologies observed in the DRG. Individual spontaneously active neurons, labeled with fluorescent dye, were 5–6 times more likely than quiescent cells to be co-localized with sympathetic fibers, suggesting a highly localized correlation of activity and sprouting. PMID:17065247

  12. Peripheral nerve explants grafted into the vitreous body of the eye promote the regeneration of retinal ganglion cell axons severed in the optic nerve.

    PubMed

    Berry, M; Carlile, J; Hunter, A

    1996-02-01

    We have conducted experiments in the adult rat visual system to assess the relative importance of an absence of trophic factors versus the presence of putative growth inhibitory molecules for the failure of regeneration of CNS axons after injury. The experiments comprised three groups of animals in which all optic nerves were crushed intra-orbitally: an optic nerve crush group had a sham implant-operation on the eye; the other two groups had peripheral nerve tissue introduced into the vitreous body; in an acellular peripheral nerve group, a frozen/thawed teased sciatic nerve segment was grafted, and in a cellular peripheral nerve group, a predegenerate teased segment of sciatic nerve was implanted. The rats were left for 20 days and their optic nerves and retinae prepared for immunohistochemical examination of both the reaction to injury of axons and glia in the nerve and also the viability of Schwann cells in the grafts. Anterograde axon tracing with rhodamine-B provided unequivocal qualitative evidence of regeneration in each group, and retrograde HRP tracing gave a measure of the numbers of axons growing across the lesion by counting HRP filled retinal ganglion cells in retinal whole mounts after HRP injection into the optic nerve distal to the lesion. No fibres crossed the lesion in the optic nerve crush group and dense scar tissue was formed in the wound site. GAP-43-positive and rhodamine-B filled axons in the acellular peripheral nerve and cellular peripheral nerve groups traversed the lesion and grew distally. There were greater numbers of regenerating fibres in the cellular peripheral nerve compared to the acellular peripheral nerve group. In the former, 0.6-10% of the retinal ganglion cell population regenerated axons at least 3-4 mm into the distal segment. In both the acellular peripheral nerve and cellular peripheral nerve groups, no basal lamina was deposited in the wound. Thus, although astrocyte processes were stacked around the lesion edge, a glia

  13. Fiber diameter distributions in the chinchilla's ampullary nerves

    NASA Technical Reports Server (NTRS)

    Hoffman, Larry F.; Honrubia, Vicente

    2002-01-01

    A morphometric study of the chinchilla's ampullary nerves was conducted to produce an unbiased accounting of the diameter distribution of their constituent fibers. Diameter analyses were determined from 1 microm plastic-embedded nerve sections taken at a plane immediately proximal to the sensory epithelium. We found these nerves to be composed of 2094+/-573 fibers, having diameters that ranged from 0.5 to 8 microm. The distributions of diameters were positively skewed, where approximately 75% of the fibers were found to have diameters less than 3.5 microm. An analysis of the spatial distribution of diameters within the nerve section revealed that the lateralmost areas of the nerve contained larger fractions of fibers within the smallest diameter quintiles, and the central area harbored greater proportions of the larger diameter quintiles. However, significant fractions of all quintiles were found in all areas. These data were integrated with available data of Fernandez et al. (1998) to produce diameter estimates of calyx, dimorphic, and bouton morphology subpopulations. In view of a general relationship between diameter, innervation locus, and an afferent's physiologic characteristics, these data provide the basis for developing a perspective for the in situ distribution of afferent response dynamics.

  14. Neuromuscular junction integrity after chronic nerve compression injury.

    PubMed

    Mozaffar, Tahseen; Strandberg, Erika; Abe, Kazuko; Hilgenberg, Lutz G; Smith, Martin A; Gupta, Ranjan

    2009-01-01

    Chronic nerve compression injuries (CNC) are progressive demyelinating disorders characterized by a gradual decline of the nerve conduction velocity (NCV) in the affected nerve region. CNC injury induces a robust Schwann cell response with axonal sprouting, but without morphologic evidence of axonal injury. We hypothesize that early CNC injury occurs without damage to neuromuscular junction of motor axons. A well-established animal model was used to assess for damage to motor axons. As sprouting is considered a hallmark of regeneration during and after axonal degeneration and sprouting was confirmed visually at 2 weeks in CNC animals, we assessed for axonal degeneration in motor nerves after CNC by evaluating the integrity of the neuromuscular junction. NCV exhibited a gradual progressive decline consistent with the human condition. Compound motor action potential amplitudes decreased slightly immediately and plateaued, indicating that there was not sustained and increasing axonal loss. Sprouting was confirmed using immunofluorescence and by an increase in number of unmyelinated axons and Remak bundles. Blind analysis of the neuromuscular junction showed no difference between control and CNC images, indicating that there was no evidence for end-unit axonal loss in the soleus muscle. Because the progressive decline in NCV was not paired with a similar progressive decline in amplitude, it is likely that axonal loss is not responsible for slowing of action potentials. Blind analysis of the neuromuscular junction provides further evidence that the axonal sprouting seen early after CNC injury is not a consequence of axonal degeneration in the motor nerves. PMID:18655131

  15. Abnormal Activity Detection Using Pyroelectric Infrared Sensors

    PubMed Central

    Luo, Xiaomu; Tan, Huoyuan; Guan, Qiuju; Liu, Tong; Zhuo, Hankz Hankui; Shen, Baihua

    2016-01-01

    Healthy aging is one of the most important social issues. In this paper, we propose a method for abnormal activity detection without any manual labeling of the training samples. By leveraging the Field of View (FOV) modulation, the spatio-temporal characteristic of human activity is encoded into low-dimension data stream generated by the ceiling-mounted Pyroelectric Infrared (PIR) sensors. The similarity between normal training samples are measured based on Kullback-Leibler (KL) divergence of each pair of them. The natural clustering of normal activities is discovered through a self-tuning spectral clustering algorithm with unsupervised model selection on the eigenvectors of a modified similarity matrix. Hidden Markov Models (HMMs) are employed to model each cluster of normal activities and form feature vectors. One-Class Support Vector Machines (OSVMs) are used to profile the normal activities and detect abnormal activities. To validate the efficacy of our method, we conducted experiments in real indoor environments. The encouraging results show that our method is able to detect abnormal activities given only the normal training samples, which aims to avoid the laborious and inconsistent data labeling process. PMID:27271632

  16. Five Roots Pattern of Median Nerve Formation.

    PubMed

    Natsis, Konstantinos; Paraskevas, George; Tzika, Maria

    2016-01-01

    An unusual combination of median nerve's variations has been encountered in a male cadaver during routine educational dissection. In particular, the median nerve was formed by five roots; three roots originated from the lateral cord of the brachial plexus joined individually the median nerve's medial root. The latter (fourth) root was united with the lateral (fifth) root of the median nerve forming the median nerve distally in the upper arm and not the axilla as usually. In addition, the median nerve was situated medial to the brachial artery. We review comprehensively the relevant variants, their embryologic development and their potential clinical applications. PMID:27131354

  17. Facial nerve paralysis in children.

    PubMed

    Ciorba, Andrea; Corazzi, Virginia; Conz, Veronica; Bianchini, Chiara; Aimoni, Claudia

    2015-12-16

    Facial nerve palsy is a condition with several implications, particularly when occurring in childhood. It represents a serious clinical problem as it causes significant concerns in doctors because of its etiology, its treatment options and its outcome, as well as in little patients and their parents, because of functional and aesthetic outcomes. There are several described causes of facial nerve paralysis in children, as it can be congenital (due to delivery traumas and genetic or malformative diseases) or acquired (due to infective, inflammatory, neoplastic, traumatic or iatrogenic causes). Nonetheless, in approximately 40%-75% of the cases, the cause of unilateral facial paralysis still remains idiopathic. A careful diagnostic workout and differential diagnosis are particularly recommended in case of pediatric facial nerve palsy, in order to establish the most appropriate treatment, as the therapeutic approach differs in relation to the etiology. PMID:26677445

  18. Facial nerve paralysis in children

    PubMed Central

    Ciorba, Andrea; Corazzi, Virginia; Conz, Veronica; Bianchini, Chiara; Aimoni, Claudia

    2015-01-01

    Facial nerve palsy is a condition with several implications, particularly when occurring in childhood. It represents a serious clinical problem as it causes significant concerns in doctors because of its etiology, its treatment options and its outcome, as well as in little patients and their parents, because of functional and aesthetic outcomes. There are several described causes of facial nerve paralysis in children, as it can be congenital (due to delivery traumas and genetic or malformative diseases) or acquired (due to infective, inflammatory, neoplastic, traumatic or iatrogenic causes). Nonetheless, in approximately 40%-75% of the cases, the cause of unilateral facial paralysis still remains idiopathic. A careful diagnostic workout and differential diagnosis are particularly recommended in case of pediatric facial nerve palsy, in order to establish the most appropriate treatment, as the therapeutic approach differs in relation to the etiology. PMID:26677445

  19. Facial nerve paralysis in children.

    PubMed

    Ciorba, Andrea; Corazzi, Virginia; Conz, Veronica; Bianchini, Chiara; Aimoni, Claudia

    2015-12-16

    Facial nerve palsy is a condition with several implications, particularly when occurring in childhood. It represents a serious clinical problem as it causes significant concerns in doctors because of its etiology, its treatment options and its outcome, as well as in little patients and their parents, because of functional and aesthetic outcomes. There are several described causes of facial nerve paralysis in children, as it can be congenital (due to delivery traumas and genetic or malformative diseases) or acquired (due to infective, inflammatory, neoplastic, traumatic or iatrogenic causes). Nonetheless, in approximately 40%-75% of the cases, the cause of unilateral facial paralysis still remains idiopathic. A careful diagnostic workout and differential diagnosis are particularly recommended in case of pediatric facial nerve palsy, in order to establish the most appropriate treatment, as the therapeutic approach differs in relation to the etiology.

  20. Embryonic anastomosis between hypoglossal nerves.

    PubMed

    Rodríguez-Vázquez, J F; Mérida-Velasco, J R; Verdugo-López, S; Sanz-Casado, J V; Jiménez-Collado, J

    2009-12-01

    This article presents two cases of anastomosis of hypoglossal nerves in the suprahyoid region in human embryos of CR length 10.75 and 17.5 mm. This variation was studied in two human specimens at this stage of development and compared with the normal arrangement of the hypoglossal nerves in embryos at the same stage. The anastomotic branches were of similar caliber to the main trunks. In both cases the anastomosis was located dorsal to the origin of the geniohyoid muscles and caudal to the genioglossus muscles, lying transversally over the cranial face of the body of the hyoid bone anlage. The anastomosis formed a suprahyoid nerve chiasm on the midline in the embryo of 10.75 mm CR length.

  1. Genetic Deletion of Cadm4 Results in Myelin Abnormalities Resembling Charcot-Marie-Tooth Neuropathy

    PubMed Central

    Golan, Neev; Kartvelishvily, Elena; Spiegel, Ivo; Salomon, Daniela; Sabanay, Helena; Rechav, Katya; Vainshtein, Anya; Frechter, Shahar; Maik-Rachline, Galia; Eshed-Eisenbach, Yael; Momoi, Takashi

    2013-01-01

    The interaction between myelinating Schwann cells and the axons they ensheath is mediated by cell adhesion molecules of the Cadm/Necl/SynCAM family. This family consists of four members: Cadm4/Necl4 and Cadm1/Necl2 are found in both glia and axons, whereas Cadm2/Necl3 and Cadm3/Necl1 are expressed by sensory and motor neurons. By generating mice lacking each of the Cadm genes, we now demonstrate that Cadm4 plays a role in the establishment of the myelin unit in the peripheral nervous system. Mice lacking Cadm4 (PGK-Cre/Cadm4fl/fl), but not Cadm1, Cadm2, or Cadm3, develop focal hypermyelination characterized by tomacula and myelin outfoldings, which are the hallmark of several Charcot-Marie-Tooth neuropathies. The absence of Cadm4 also resulted in abnormal axon–glial contact and redistribution of ion channels along the axon. These neuropathological features were also found in transgenic mice expressing a dominant-negative mutant of Cadm4 lacking its cytoplasmic domain in myelinating glia Tg(mbp-Cadm4dCT), as well as in mice lacking Cadm4 specifically in Schwann cells (DHH-Cre/Cadm4fl/fl). Consistent with these abnormalities, both PGK-Cre/Cadm4fl/fl and Tg(mbp-Cadm4dCT) mice exhibit impaired motor function and slower nerve conduction velocity. These findings indicate that Cadm4 regulates the growth of the myelin unit and the organization of the underlying axonal membrane. PMID:23825401

  2. Episomal Induced Pluripotent Stem Cells Promote Functional Recovery of Transected Murine Peripheral Nerve

    PubMed Central

    Kao, Huang-Kai; Cardona, Esteban; Chuang, Sheng-Hao

    2016-01-01

    Traumatic peripheral nerve neurotmesis occurs frequently and functional recovery is often slow and impaired. Induced pluripotent stem cells (iPSCs) have shown much promise in recent years due to its regenerative properties similar to that of embryonic stem cells. However, the potential of iPSCs in promoting the functional recovery of a transected peripheral nerve is largely unknown. This study is the first to investigate in vivo effects of episomal iPSCs (EiPSCs) on peripheral nerve regeneration in a murine sciatic nerve transection model. Episomal iPSCs refer to iPSCs that are generated via Oct3/4-Klf4-Sox2 plasmid reprogramming instead of the conventional viral insertion techniques. It represents a relatively safer form of iPSC production without permanent transgene integration which may raise questions regarding risks of genomic mutation. A minimal number of EiPSCs were added directly to the transected nerve. Functional recovery of the EiPSC group was significantly improved compared to the negative control group when assessed via serial five-toe spread measurement and gait analysis of ankle angles. EiPSC promotion of nerve regeneration was also evident on stereographic analysis of axon density, myelin thickness, and axonal cross-sectional surface area. Most importantly, the results observed in EiPSCs are similar to that of the embryonic stem cell group. A roughly ten-fold increase in neurotrophin-3 levels was seen in EiPSCs which could have contributed to peripheral nerve regeneration and recovery. No abnormal masses or adverse effects were noted with EiPSC administration after one year of follow-up. We have hence shown that functional recovery of the transected peripheral nerve can be improved with the use of EiPSC therapy, which holds promise for the future of nerve regeneration. PMID:27736950

  3. A Human Hair Keratin Hydrogel Scaffold Enhances Median Nerve Regeneration in Nonhuman Primates: An Electrophysiological and Histological Study

    PubMed Central

    Pace, Lauren A.; Plate, Johannes F.; Mannava, Sandeep; Barnwell, Jonathan C.; Koman, L. Andrew; Li, Zhongyu; Smith, Thomas L.

    2014-01-01

    A human hair keratin biomaterial hydrogel scaffold was evaluated as a nerve conduit luminal filler following median nerve transection injury in 10 Macaca fascicularis nonhuman primates (NHP). A 1 cm nerve gap was grafted with a NeuraGen® collagen conduit filled with either saline or keratin hydrogel and nerve regeneration was evaluated by electrophysiology for a period of 12 months. The keratin hydrogel-grafted nerves showed significant improvement in return of compound motor action potential (CMAP) latency and recovery of baseline nerve conduction velocity (NCV) compared with the saline-treated nerves. Histological evaluation was performed on retrieved median nerves and abductor pollicis brevis (APB) muscles at 12 months. Nerve histomorphometry showed a significantly larger nerve area in the keratin group compared with the saline group and the keratin APB muscles had a significantly higher myofiber density than the saline group. This is the first published study to show that an acellular biomaterial hydrogel conduit filler can be used to enhance peripheral nerve regeneration and motor recovery in an NHP model. PMID:24083825

  4. Rehabilitation of peripheral nerve injuries.

    PubMed

    Robinson, Michael D; Shannon, Steven

    2002-02-01

    Traumatic injuries to peripheral nerves pose complex challenges to both military and civilian physicians. Treatment of nerve injuries must consider all aspects of the inherent disability. Pain control is of paramount importance. Little will be accomplished until pain is brought down to tolerable levels. Rehabilitation needs to be instituted as first-line treatment. Focus must be first placed on protection of the affected area from complications stemming from disuse and immobility and then on enhancement of strength, flexibility, sensory discrimination, and dexterity. Early intervention sets the stage for optimal physiologic and functional recovery. PMID:11878078

  5. Nerve lesioning with direct current

    NASA Astrophysics Data System (ADS)

    Ravid, E. Natalie; Shi Gan, Liu; Todd, Kathryn; Prochazka, Arthur

    2011-02-01

    Spastic hypertonus (muscle over-activity due to exaggerated stretch reflexes) often develops in people with stroke, cerebral palsy, multiple sclerosis and spinal cord injury. Lesioning of nerves, e.g. with phenol or botulinum toxin is widely performed to reduce spastic hypertonus. We have explored the use of direct electrical current (DC) to lesion peripheral nerves. In a series of animal experiments, DC reduced muscle force by controlled amounts and the reduction could last several months. We conclude that in some cases controlled DC lesioning may provide an effective alternative to the less controllable molecular treatments available today.

  6. Nonrecurrent Laryngeal Nerve in the Era of Intraoperative Nerve Monitoring

    PubMed Central

    Gurleyik, Gunay

    2016-01-01

    Nonrecurrent laryngeal nerve (non-RLN) is an anatomical variation increasing the risk of vocal cord palsy. Prediction and early identification of non-RLN may minimize such a risk of injury. This study assessed the effect of intraoperative neuromonitoring (IONM) on the detection of non-RLN. A total of 462 (236 right) nerves in 272 patients were identified and totally exposed, and all intraoperative steps of IONM were sequentially applied on the vagus nerve (VN) and RLN. Right predissection VN stimulation at a distal point did not create a sound signal in three cases (3/236; 1.27%). Proximal dissection of the right VN under IONM guidance established a proximal point, creating a positive signal. The separation point of non-RLN from VN was discovered in all three patients. Non-RLNs were exposed from separation to laryngeal entry. Positive IONM signals were obtained after resection of thyroid lobes, and postoperative period was uneventful in patients with non-RLN. Absence of distal VN signal is a precise predictor of the non-RLN. IONM-guided proximal dissection of the right VN leads to identification of the non-RLN. The prediction of non-RLN by the absence of the VN signal at an early stage of surgery may prevent or minimize the risk of nerve injury.

  7. The coexistence of peripheral nerve sheath tumors and vitiligo: more than coincidence?

    PubMed

    Elsherif, Mohamed A; Spinner, Robert J; Miest, Rachel Y

    2016-01-01

    Neurocristopathies arise from abnormal migration, differentiation, or proliferation of neural crest derivatives, leading to diverse clinical and pathological features. They are classified into dysgenetic or neoplastic, and can affect single or multiple sites (simple versus complex). Examples include congenital melanocytic nevi, neuroblastoma, Hirshsprung's disease, Waardenburg's syndrome, neurofibromatosis (NF) 1 and multiple endocrine neoplasia (MEN) 2A and 2B. We report two cases of peripheral nerve sheath tumors associated with vitiligo and discuss the possible implicated embryologic, genetic and molecular mechanisms. To our knowledge, we also report the first case of de novo malignant peripheral nerve sheath tumor (MPNST) associated with vitiligo. PMID:26607956

  8. The coexistence of peripheral nerve sheath tumors and vitiligo: more than coincidence?

    PubMed

    Elsherif, Mohamed A; Spinner, Robert J; Miest, Rachel Y

    2016-01-01

    Neurocristopathies arise from abnormal migration, differentiation, or proliferation of neural crest derivatives, leading to diverse clinical and pathological features. They are classified into dysgenetic or neoplastic, and can affect single or multiple sites (simple versus complex). Examples include congenital melanocytic nevi, neuroblastoma, Hirshsprung's disease, Waardenburg's syndrome, neurofibromatosis (NF) 1 and multiple endocrine neoplasia (MEN) 2A and 2B. We report two cases of peripheral nerve sheath tumors associated with vitiligo and discuss the possible implicated embryologic, genetic and molecular mechanisms. To our knowledge, we also report the first case of de novo malignant peripheral nerve sheath tumor (MPNST) associated with vitiligo.

  9. Kidney transplantation in abnormal bladder

    PubMed Central

    Mishra, Shashi K.; Muthu, V.; Rajapurkar, Mohan M.; Desai, Mahesh R.

    2007-01-01

    Structural urologic abnormalities resulting in dysfunctional lower urinary tract leading to end stage renal disease may constitute 15% patients in the adult population and up to 20-30% in the pediatric population. A patient with an abnormal bladder, who is approaching end stage renal disease, needs careful evaluation of the lower urinary tract to plan the most satisfactory technical approach to the transplant procedure. Past experience of different authors can give an insight into the management and outcome of these patients. This review revisits the current literature available on transplantation in abnormal bladder and summarizes the clinical approach towards handling this group of difficult transplant patients. We add on our experience as we discuss the various issues. The outcome of renal transplant in abnormal bladder is not adversely affected when done in a reconstructed bladder. Correct preoperative evaluation, certain technical modification during transplant and postoperative care is mandatory to avoid complications. Knowledge of the abnormal bladder should allow successful transplantation with good outcome. PMID:19718334

  10. Radiographic abnormalities among construction workers exposed to quartz containing dust

    PubMed Central

    Tjoe, N; Burdorf, A; Parker, J; Attfield, M; van Duivenbooden, C; Heederik, D

    2003-01-01

    Background: Construction workers are exposed to quartz containing respirable dust, at levels that may cause fibrosis in the lungs. Studies so far have not established a dose-response relation for radiographic abnormalities for this occupational group. Aims: To measure the extent of radiographic abnormalities among construction workers primarily exposed to quartz containing respirable dust. Methods: A cross sectional study on radiographic abnormalities indicative of pneumoconiosis was conducted among 1339 construction workers mainly involved in grinding, (jack)-hammering, drilling, cutting, sawing, and polishing. Radiological abnormalities were determined by median results of the 1980 International Labour Organisation system of three certified "B" readers. Questionnaires were used for assessment of occupational history, presence of respiratory diseases, and symptoms and smoking habits. Results: An abnormality of ILO profusion category 1/0 and greater was observed on 10.2% of the chest radiographs, and profusion category of 1/1 or greater on 2.9% of the radiographs. The average duration of exposure of this group was 19 years and the average age was 42. The predominant type of small opacities (irregularly shaped) is presumably indicative of mixed dust pneumoconiosis. The prevalence of early signs of nodular silicosis (small rounded opacities of category 1/0 or greater) was low (0.8%). Conclusions: The study suggests an elevated risk of radiographic abnormalities among these workers with expected high exposure. An association between radiographic abnormalities and cumulative exposure to quartz containing dust from construction sites was observed, after correction for potentially confounding variables. PMID:12771392

  11. Molecular mechanisms of nerve block by local anesthetics.

    PubMed

    Strichartz, G

    1976-10-01

    Local anesthetics block nerve conduction by preventing the increase in membrane permeability to sodium ions that normally leads to a nerve impulse. Among anesthetics containing tertiary amine groups, the cationic, protonated form appears to be more active than the neutral form. However, the neutral forms, as well as uncharged molecules like benzocaine and the aliphatic alcohols, also depress sodium permeability. Studies of single myelinated nerves and squid axons show no direct interaction between calcium ions and local anesthetics, thus disproving theories based on competition between these two agents. Likewise, hypotheses attributing local anesthesia to changes in electrical potentials at the membrane-water interface are disproven by the demonstrated potencies of electrically uncharged anesthetics. Hypotheses that propose that local anesthetics act by expanding the nerve membrane and causing a change in protein conformation that blocks sodium permeability are vague in conception and difficult to test experimentally. Evidence from voltage-clamp studies of single nerve fibers indicates that anesthetic molecules interact with the sodium channels directly, from the inner side of the nerve membrane. Anesthetics bind within sodium channels which have opened during membrane depolarization, preventing the normal sodium ion flux. Anesthetic molecules can dissociate from open channels, but not from channels that remain closed when the nerve is kept at rest. The "gating" properties that regulate the opening and closing of sodium channels are reversibly modified during anesthesia. Specifically, the inactivation function responds more slowly and requires more negative membrane potential changes to reach the same values as in unanesthetized nerves. A second, slow inactivation is observed following external application of tertiary amine anesthetics. The selective binding of anesthetics to open sodium channels provides a simple explanation for Wedenski inhibition, in which the

  12. Complex patterns of abnormal heartbeats

    NASA Technical Reports Server (NTRS)

    Schulte-Frohlinde, Verena; Ashkenazy, Yosef; Goldberger, Ary L.; Ivanov, Plamen Ch; Costa, Madalena; Morley-Davies, Adrian; Stanley, H. Eugene; Glass, Leon

    2002-01-01

    Individuals having frequent abnormal heartbeats interspersed with normal heartbeats may be at an increased risk of sudden cardiac death. However, mechanistic understanding of such cardiac arrhythmias is limited. We present a visual and qualitative method to display statistical properties of abnormal heartbeats. We introduce dynamical "heartprints" which reveal characteristic patterns in long clinical records encompassing approximately 10(5) heartbeats and may provide information about underlying mechanisms. We test if these dynamics can be reproduced by model simulations in which abnormal heartbeats are generated (i) randomly, (ii) at a fixed time interval following a preceding normal heartbeat, or (iii) by an independent oscillator that may or may not interact with the normal heartbeat. We compare the results of these three models and test their limitations to comprehensively simulate the statistical features of selected clinical records. This work introduces methods that can be used to test mathematical models of arrhythmogenesis and to develop a new understanding of underlying electrophysiologic mechanisms of cardiac arrhythmia.

  13. Proximal Sciatic Nerve Intraneural Ganglion Cyst

    PubMed Central

    Swartz, Karin R.; Wilson, Dianne; Boland, Michael; Fee, Dominic B.

    2009-01-01

    Intraneural ganglion cysts are nonneoplastic, mucinous cysts within the epineurium of peripheral nerves which usually involve the peroneal nerve at the knee. A 37-year-old female presented with progressive left buttock and posterior thigh pain. Magnetic resonance imaging revealed a sciatic nerve mass at the sacral notch which was subsequently revealed to be an intraneural ganglion cyst. An intraneural ganglion cyst confined to the proximal sciatic nerve has only been reported once prior to 2009. PMID:20069041

  14. Patterned substrates and methods for nerve regeneration

    DOEpatents

    Mallapragada, Surya K.; Heath, Carole; Shanks, Howard; Miller, Cheryl A.; Jeftinija, Srdija

    2004-01-13

    Micropatterned substrates and methods for fabrication of artificial nerve regeneration conduits and methods for regenerating nerves are provided. Guidance compounds or cells are seeded in grooves formed on the patterned substrate. The substrates may also be provided with electrodes to provide electrical guidance cues to the regenerating nerve. The micropatterned substrates give physical, chemical, cellular and/or electrical guidance cues to promote nerve regeneration at the cellular level.

  15. [Emotion Disorders and Abnormal Perspiration].

    PubMed

    Umeda, Satoshi

    2016-08-01

    This article reviewed the relationship between emotional disorders and abnormal perspiration. First, I focused on local brain areas related to emotional processing, and summarized the functions of the emotional network involving those local areas. Functional disorders followed by the damage in the amygdala, orbitofrontal cortex, and insular cortex were reviewed, including related abnormal perspiration. I then addressed the mechanisms of how autonomic disorders influence emotional processing. Finally, possible future directions for integrated understanding of the connection between neural activities and bodily reactions were discussed. PMID:27503817

  16. [Emotion Disorders and Abnormal Perspiration].

    PubMed

    Umeda, Satoshi

    2016-08-01

    This article reviewed the relationship between emotional disorders and abnormal perspiration. First, I focused on local brain areas related to emotional processing, and summarized the functions of the emotional network involving those local areas. Functional disorders followed by the damage in the amygdala, orbitofrontal cortex, and insular cortex were reviewed, including related abnormal perspiration. I then addressed the mechanisms of how autonomic disorders influence emotional processing. Finally, possible future directions for integrated understanding of the connection between neural activities and bodily reactions were discussed.

  17. Peripheral nerve magnetic stimulation: influence of tissue non-homogeneity

    PubMed Central

    Krasteva, Vessela TZ; Papazov, Sava P; Daskalov, Ivan K

    2003-01-01

    Background Peripheral nerves are situated in a highly non-homogeneous environment, including muscles, bones, blood vessels, etc. Time-varying magnetic field stimulation of the median and ulnar nerves in the carpal region is studied, with special consideration of the influence of non-homogeneities. Methods A detailed three-dimensional finite element model (FEM) of the anatomy of the wrist region was built to assess the induced currents distribution by external magnetic stimulation. The electromagnetic field distribution in the non-homogeneous domain was defined as an internal Dirichlet problem using the finite element method. The boundary conditions were obtained by analysis of the vector potential field excited by external current-driven coils. Results The results include evaluation and graphical representation of the induced current field distribution at various stimulation coil positions. Comparative study for the real non-homogeneous structure with anisotropic conductivities of the tissues and a mock homogeneous media is also presented. The possibility of achieving selective stimulation of either of the two nerves is assessed. Conclusion The model developed could be useful in theoretical prediction of the current distribution in the nerves during diagnostic stimulation and therapeutic procedures involving electromagnetic excitation. The errors in applying homogeneous domain modeling rather than real non-homogeneous biological structures are demonstrated. The practical implications of the applied approach are valid for any arbitrary weakly conductive medium. PMID:14693034

  18. Effect of Artificial Nerve Conduit Vascularization on Peripheral Nerve in a Necrotic Bed

    PubMed Central

    Iijima, Yuki; Murayama, Akira; Takeshita, Katsushi

    2016-01-01

    Background: Several types of artificial nerve conduit have been used for bridging peripheral nerve gaps as an alternative to autologous nerves. However, their efficacy in repairing nerve injuries accompanied by surrounding tissue damage remains unclear. We fabricated a novel nerve conduit vascularized by superficial inferior epigastric (SIE) vessels and evaluated whether it could promote axonal regeneration in a necrotic bed. Methods: A 15-mm nerve conduit was implanted beneath the SIE vessels in the groin of a rat to supply it with blood vessels 2 weeks before nerve reconstruction. We removed a 13-mm segment of the sciatic nerve and then pressed a heated iron against the dorsal thigh muscle to produce a burn. The defects were immediately repaired with an autograft (n = 10), nerve conduit graft (n = 8), or vascularized nerve conduit graft (n = 8). Recovery of motor function was examined for 18 weeks after surgery. The regenerated nerves were electrophysiologically and histologically evaluated. Results: The vascularity of the nerve conduit implanted beneath the SIE vessels was confirmed histologically 2 weeks after implantation. Between 14 and 18 weeks after surgery, motor function of the vascularized conduit group was significantly better than that of the nonvascularized conduit group. Electrophysiological and histological evaluations revealed that although the improvement did not reach the level of reinnervation achieved by an autograft, the vascularized nerve conduit improved axonal regeneration more than did the conduit alone. Conclusion: Vascularization of artificial nerve conduits accelerated peripheral nerve regeneration, but further research is required to improve the quality of nerve regeneration. PMID:27257595

  19. An anatomical study of porcine peripheral nerve and its potential use in nerve tissue engineering

    PubMed Central

    Zilic, Leyla; Garner, Philippa E; Yu, Tong; Roman, Sabiniano; Haycock, John W; Wilshaw, Stacy-Paul

    2015-01-01

    Current nerve tissue engineering applications are adopting xenogeneic nerve tissue as potential nerve grafts to help aid nerve regeneration. However, there is little literature that describes the exact location, anatomy and physiology of these nerves to highlight their potential as a donor graft. The aim of this study was to identify and characterise the structural and extracellular matrix (ECM) components of porcine peripheral nerves in the hind leg. Methods included the dissection of porcine nerves, localisation, characterisation and quantification of the ECM components and identification of nerve cells. Results showed a noticeable variance between porcine and rat nerve (a commonly studied species) in terms of fascicle number. The study also revealed that when porcine peripheral nerves branch, a decrease in fascicle number and size was evident. Porcine ECM and nerve fascicles were found to be predominately comprised of collagen together with glycosaminoglycans, laminin and fibronectin. Immunolabelling for nerve growth factor receptor p75 also revealed the localisation of Schwann cells around and inside the fascicles. In conclusion, it is shown that porcine peripheral nerves possess a microstructure similar to that found in rat, and is not dissimilar to human. This finding could extend to the suggestion that due to the similarities in anatomy to human nerve, porcine nerves may have utility as a nerve graft providing guidance and support to regenerating axons. PMID:26200940

  20. Quantifying Demyelination in NK venom treated nerve using its electric circuit model

    NASA Astrophysics Data System (ADS)

    Das, H. K.; Das, D.; Doley, R.; Sahu, P. P.

    2016-03-01

    Reduction of myelin in peripheral nerve causes critical demyelinating diseases such as chronic inflammatory demyelinating polyneuropathy, Guillain-Barre syndrome, etc. Clinical monitoring of these diseases requires rapid and non-invasive quantification of demyelination. Here we have developed formulation of nerve conduction velocity (NCV) in terms of demyelination considering electric circuit model of a nerve having bundle of axons for its quantification from NCV measurements. This approach has been validated and demonstrated with toad nerve model treated with crude Naja kaouthia (NK) venom and also shows the effect of Phospholipase A2 and three finger neurotoxin from NK-venom on peripheral nerve. This opens future scope for non-invasive clinical measurement of demyelination.

  1. Wallerian Degeneration and Recovery of Motor Nerves after Multiple Focused Cold Therapies

    PubMed Central

    Hsu, Michael; Stevenson, Fang F

    2015-01-01

    Introduction: A device has been developed to apply freezing temperatures to temporarily impede nerve conduction, resulting in inhibition of voluntary skeletal muscle contraction. This device was designed as an alternative to the neurotoxins usually used to treat movement disorders. Methods: We evaluated the effects of single and 3 repeat treatments with a cryoprobe device (−55°C) on a sciatic nerve rat model. Long-term effects of repeated treatment were evaluated through assessments of physiological function and histological analysis. Results: There was consistent weakening of physiological function after each treatment, with recovery of normal function by 8 weeks posttreatment. Histological findings showed axonal degeneration with no disruption to the epineurial or perineurial structures. Progressive axonal regeneration was followed by normal recovery by 24 weeks post-treatment. Conclusions: Low-temperature treatment of motor nerves did not result in permanent or long-term changes to nerve function or structure. Muscle Nerve 51: 268–275, 2015 PMID:24895229

  2. Quantifying Demyelination in NK venom treated nerve using its electric circuit model.

    PubMed

    Das, H K; Das, D; Doley, R; Sahu, P P

    2016-01-01

    Reduction of myelin in peripheral nerve causes critical demyelinating diseases such as chronic inflammatory demyelinating polyneuropathy, Guillain-Barre syndrome, etc. Clinical monitoring of these diseases requires rapid and non-invasive quantification of demyelination. Here we have developed formulation of nerve conduction velocity (NCV) in terms of demyelination considering electric circuit model of a nerve having bundle of axons for its quantification from NCV measurements. This approach has been validated and demonstrated with toad nerve model treated with crude Naja kaouthia (NK) venom and also shows the effect of Phospholipase A2 and three finger neurotoxin from NK-venom on peripheral nerve. This opens future scope for non-invasive clinical measurement of demyelination. PMID:26932543

  3. Quantifying Demyelination in NK venom treated nerve using its electric circuit model

    PubMed Central

    Das, H. K.; Das, D.; Doley, R.; Sahu, P. P.

    2016-01-01

    Reduction of myelin in peripheral nerve causes critical demyelinating diseases such as chronic inflammatory demyelinating polyneuropathy, Guillain-Barre syndrome, etc. Clinical monitoring of these diseases requires rapid and non-invasive quantification of demyelination. Here we have developed formulation of nerve conduction velocity (NCV) in terms of demyelination considering electric circuit model of a nerve having bundle of axons for its quantification from NCV measurements. This approach has been validated and demonstrated with toad nerve model treated with crude Naja kaouthia (NK) venom and also shows the effect of Phospholipase A2 and three finger neurotoxin from NK-venom on peripheral nerve. This opens future scope for non-invasive clinical measurement of demyelination. PMID:26932543

  4. Diffusion-weighted magnetic resonance imaging of the ulnar nerve in cubital tunnel syndrome.

    PubMed

    Iba, K; Wada, T; Tamakawa, M; Aoki, M; Yamashita, T

    2010-01-01

    Diffusion-weighted images based on magnetic resonance reveal the microstructure of tissues by monitoring the random movement of water molecules. In this study, we investigated whether this new technique could visualize pathologic lesions on ulnar nerve in cubital tunnel. Six elbows in six healthy males without any symptoms and eleven elbows in ten patients with cubital tunnel syndrome underwent on diffusion-weighted MRI. No signal from the ulnar nerve was detected in normal subjects. Diffusion-weighted MRI revealed positive signals from the ulnar nerve in all of the eleven elbows with cubital tunnel syndrome. In contrast, conventional T2W-MRI revealed high signal intensity in eight elbows and low signal intensity in three elbows. Three elbows with low signal MRI showed normal nerve conduction velocity of the ulnar nerve. Diffusion-weighted MRI appears to be an attractive technique for diagnosis of cubital tunnel syndrome in its early stages which show normal electrophysiological and conventional MRI studies.

  5. Overview of Optic Nerve Disorders

    MedlinePlus

    ... pathways to the brain results in loss of vision. At a structure in the brain called the optic chiasm, each optic nerve splits, ... both eyes, and the left side of the brain receives information from the right visual field of both eyes. ... occurs. Resources ...

  6. Cryoanalgesia for painful peripheral nerve lesions.

    PubMed

    Wang, J K

    1985-06-01

    Twelve patients with chronically painful peripheral nerve lesions were treated with cryoanalgesia. The pain was relieved in 6 patients for 1-12 months. Although the pain eventually recurred, the patients resumed normal activities during remission. It is necessary to improve the techniques of nerve localization and to determine the proper mode of nerve freezing. PMID:2995903

  7. Altered peripheral nerve function resulting from haemodialysis.

    PubMed

    Stanley, E; Brown, J C; Pryor, J S

    1977-01-01

    The amplitudes of muscle and nerve action potentials evoked median nerve stimulation were recorded just before and immediately after haemodialysis. These revealed a growht of action potential amplitude during dialysis. It is suggested that some component of the defective peripheral nerve function that inevitably accompanies uraemia is temporarily improved during dialysis. PMID:845605

  8. Trigeminal nerve: Anatomic correlation with MR imaging

    SciTech Connect

    Daniels, D.L.; Pech, P.; Pojunas, K.W.; Kilgore, D.P.; Williams, A.L.; Haughton, V.M.

    1986-06-01

    Through correlation with cryomicrotic sections, the appearance of the trigeminal nerve and its branches on magnetic resonance images is described in healthy individuals and in patients with tumors involving this nerve. Coronal images are best for defining the different parts of the nerve and for making a side-to-side comparison. Sagittal images are useful to demonstrate tumors involving the Gasserian ganglion.

  9. 21 CFR 882.5275 - Nerve cuff.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Nerve cuff. 882.5275 Section 882.5275 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Therapeutic Devices § 882.5275 Nerve cuff. (a) Identification. A nerve...

  10. Mobility-Related Consequences of Reduced Lower-Extremity Peripheral Nerve Function with Age: A Systematic Review.

    PubMed

    Ward, Rachel E; Caserotti, Paolo; Cauley, Jane A; Boudreau, Robert M; Goodpaster, Bret H; Vinik, Aaron I; Newman, Anne B; Strotmeyer, Elsa S

    2016-08-01

    The objective of this study is to systematically review the relationship between lower-extremity peripheral nerve function and mobility in older adults. The National Library of Medicine (PubMed) was searched on March 23, 2015 with no limits on publication dates. One reviewer selected original research studies of older adults (≥65 years) that assessed the relationship between lower-extremity peripheral nerve function and mobility-related outcomes. Participants, study design and methods of assessing peripheral nerve impairment were evaluated and results were reported and synthesized. Eight articles were identified, including 6 cross-sectional and 2 longitudinal studies. These articles investigated 6 elderly cohorts (4 from the U.S. and 2 from Italy): 3 community-dwelling (including 1 with only disabled women and 1 without mobility limitations at baseline), 1 with both community-dwelling and institutionalized residents, 1 from a range of residential locations, and 1 of patients with peripheral arterial disease. Mean ages ranged from 71-82 years. Nerve function was assessed by vibration threshold (n=2); sensory measures and clinical signs and symptoms of neuropathy (n=2); motor nerve conduction (n=1); and a combination of both sensory measures and motor nerve conduction (n=3). Each study found that worse peripheral nerve function was related to poor mobility, although relationships varied based on the nerve function measure and mobility domain assessed. Six studies found that the association between nerve function and mobility persisted despite adjustment for diabetes. Evidence suggests that peripheral nerve function impairment at various levels of severity is related to poor mobility independent of diabetes. Relationships varied depending on peripheral nerve measure, which may be particularly important when investigating specific biological mechanisms. Future research needs to identify risk factors for peripheral nerve decline beyond diabetes, especially those

  11. Mobility-Related Consequences of Reduced Lower-Extremity Peripheral Nerve Function with Age: A Systematic Review.

    PubMed

    Ward, Rachel E; Caserotti, Paolo; Cauley, Jane A; Boudreau, Robert M; Goodpaster, Bret H; Vinik, Aaron I; Newman, Anne B; Strotmeyer, Elsa S

    2016-08-01

    The objective of this study is to systematically review the relationship between lower-extremity peripheral nerve function and mobility in older adults. The National Library of Medicine (PubMed) was searched on March 23, 2015 with no limits on publication dates. One reviewer selected original research studies of older adults (≥65 years) that assessed the relationship between lower-extremity peripheral nerve function and mobility-related outcomes. Participants, study design and methods of assessing peripheral nerve impairment were evaluated and results were reported and synthesized. Eight articles were identified, including 6 cross-sectional and 2 longitudinal studies. These articles investigated 6 elderly cohorts (4 from the U.S. and 2 from Italy): 3 community-dwelling (including 1 with only disabled women and 1 without mobility limitations at baseline), 1 with both community-dwelling and institutionalized residents, 1 from a range of residential locations, and 1 of patients with peripheral arterial disease. Mean ages ranged from 71-82 years. Nerve function was assessed by vibration threshold (n=2); sensory measures and clinical signs and symptoms of neuropathy (n=2); motor nerve conduction (n=1); and a combination of both sensory measures and motor nerve conduction (n=3). Each study found that worse peripheral nerve function was related to poor mobility, although relationships varied based on the nerve function measure and mobility domain assessed. Six studies found that the association between nerve function and mobility persisted despite adjustment for diabetes. Evidence suggests that peripheral nerve function impairment at various levels of severity is related to poor mobility independent of diabetes. Relationships varied depending on peripheral nerve measure, which may be particularly important when investigating specific biological mechanisms. Future research needs to identify risk factors for peripheral nerve decline beyond diabetes, especially those

  12. Potential Involvement of Draxin in the Axonal Projection of Cranial Nerves, Especially Cranial Nerve X, in the Chick Hindbrain.

    PubMed

    Zhang, Sanbing; Cui, Huixian; Wang, Lei; Kang, Lin; Huang, Guannan; Du, Juan; Li, Sha; Tanaka, Hideaki; Su, Yuhong

    2016-07-01

    The appropriate projection of axons within the nervous system is a crucial component of the establishment of neural circuitry. Draxin is a repulsive axon guidance protein. Draxin has important functions in the guidance of three commissures in the central nervous system and in the migration of neural crest cells and dI3 interneurons in the chick spinal cord. Here, we report that the distribution of the draxin protein and the location of 23C10-positive areas have a strong temporal and spatial correlation. The overexpression of draxin, especially transmembrane draxin, caused 23C10-positive axon bundles to misproject in the dorsal hindbrain. In addition, the overexpression of transmembrane draxin caused abnormal formation of the ganglion crest of the IX and X cranial nerves, misprojection of some anti-human natural killer-1 (HNK-1)-stained structures in the dorsal roof of the hindbrain, and a simultaneous reduction in the efferent nerves of some motoneuron axons inside the hindbrain. Our data reveal that draxin might be involved in the fascicular projection of cranial nerves in the hindbrain. PMID:27199282

  13. Potential Involvement of Draxin in the Axonal Projection of Cranial Nerves, Especially Cranial Nerve X, in the Chick Hindbrain.

    PubMed

    Zhang, Sanbing; Cui, Huixian; Wang, Lei; Kang, Lin; Huang, Guannan; Du, Juan; Li, Sha; Tanaka, Hideaki; Su, Yuhong

    2016-07-01

    The appropriate projection of axons within the nervous system is a crucial component of the establishment of neural circuitry. Draxin is a repulsive axon guidance protein. Draxin has important functions in the guidance of three commissures in the central nervous system and in the migration of neural crest cells and dI3 interneurons in the chick spinal cord. Here, we report that the distribution of the draxin protein and the location of 23C10-positive areas have a strong temporal and spatial correlation. The overexpression of draxin, especially transmembrane draxin, caused 23C10-positive axon bundles to misproject in the dorsal hindbrain. In addition, the overexpression of transmembrane draxin caused abnormal formation of the ganglion crest of the IX and X cranial nerves, misprojection of some anti-human natural killer-1 (HNK-1)-stained structures in the dorsal roof of the hindbrain, and a simultaneous reduction in the efferent nerves of some motoneuron axons inside the hindbrain. Our data reveal that draxin might be involved in the fascicular projection of cranial nerves in the hindbrain.

  14. Assessment of Median Nerve Mobility by Ultrasound Dynamic Imaging for Diagnosing Carpal Tunnel Syndrome.

    PubMed

    Kuo, Tai-Tzung; Lee, Ming-Ru; Liao, Yin-Yin; Chen, Jiann-Perng; Hsu, Yen-Wei; Yeh, Chih-Kuang

    2016-01-01

    Carpal tunnel syndrome (CTS) is the most common peripheral neuropathy and is characterized by median nerve entrapment at the wrist and the resulting median nerve dysfunction. CTS is diagnosed clinically as the gold standard and confirmed with nerve conduction studies (NCS). Complementing NCS, ultrasound imaging could provide additional anatomical information on pathological and motion changes of the median nerve. The purpose of this study was to estimate the transverse sliding patterns of the median nerve during finger movements by analyzing ultrasound dynamic images to distinguish between normal subjects and CTS patients. Transverse ultrasound images were acquired, and a speckle-tracking algorithm was used to determine the lateral displacements of the median nerve in radial-ulnar plane in B-mode images utilizing the multilevel block-sum pyramid algorithm and averaging. All of the averaged lateral displacements at separate acquisition times within a single flexion-extension cycle were accumulated to obtain the cumulative lateral displacements, which were curve-fitted with a second-order polynomial function. The fitted curve was regarded as the transverse sliding pattern of the median nerve. The R2 value, curvature, and amplitude of the fitted curves were computed to evaluate the goodness, variation and maximum value of the fit, respectively. Box plots, the receiver operating characteristic (ROC) curve, and a fuzzy c-means clustering algorithm were utilized for statistical analysis. The transverse sliding of the median nerve during finger movements was greater and had a steeper fitted curve in the normal subjects than in the patients with mild or severe CTS. The temporal changes in transverse sliding of the median nerve within the carpal tunnel were found to be correlated with the presence of CTS and its severity. The representative transverse sliding patterns of the median nerve during finger movements were demonstrated to be useful for quantitatively estimating

  15. Detection of peripheral nerve pathology

    PubMed Central

    Seelig, Michael J.; Baker, Jonathan C.; Mackinnon, Susan E.; Pestronk, Alan

    2013-01-01

    Objective: To compare accuracy of ultrasound and MRI for detecting focal peripheral nerve pathology, excluding idiopathic carpal or cubital tunnel syndromes. Methods: We performed a retrospective review of patients referred for neuromuscular ultrasound to identify patients who had ultrasound and MRI of the same limb for suspected brachial plexopathy or mononeuropathies, excluding carpal/cubital tunnel syndromes. Ultrasound and MRI results were compared to diagnoses determined by surgical or, if not performed, clinical/electrodiagnostic evaluation. Results: We identified 53 patients who had both ultrasound and MRI of whom 46 (87%) had nerve pathology diagnosed by surgical (n = 39) or clinical/electrodiagnostic (n = 14) evaluation. Ultrasound detected the diagnosed nerve pathology (true positive) more often than MRI (43/46 vs 31/46, p < 0.001). Nerve pathology was correctly excluded (true negative) with equal frequency by MRI and ultrasound (both 6/7). In 25% (13/53), ultrasound was accurate (true positive or true negative) when MRI was not. These pathologies were typically (10/13) long (>2 cm) and only occasionally (2/13) outside the MRI field of view. MRI missed multifocal pathology identified with ultrasound in 6 of 7 patients, often (5/7) because pathology was outside the MRI field of view. Conclusions: Imaging frequently detects peripheral nerve pathology and contributes to the differential diagnosis in patients with mononeuropathies and brachial plexopathies. Ultrasound is more sensitive than MRI (93% vs 67%), has equivalent specificity (86%), and better identifies multifocal lesions than MRI. In sonographically accessible regions ultrasound is the preferred initial imaging modality for anatomic evaluation of suspected peripheral nervous system lesions. PMID:23553474

  16. Can Automated Imaging for Optic Disc and Retinal Nerve Fiber Layer Analysis Aid Glaucoma Detection?

    PubMed Central

    Banister, Katie; Boachie, Charles; Bourne, Rupert; Cook, Jonathan; Burr, Jennifer M.; Ramsay, Craig; Garway-Heath, David; Gray, Joanne; McMeekin, Peter; Hernández, Rodolfo; Azuara-Blanco, Augusto

    2016-01-01

    Purpose To compare the diagnostic performance of automated imaging for glaucoma. Design Prospective, direct comparison study. Participants Adults with suspected glaucoma or ocular hypertension referred to hospital eye services in the United Kingdom. Methods We evaluated 4 automated imaging test algorithms: the Heidelberg Retinal Tomography (HRT; Heidelberg Engineering, Heidelberg, Germany) glaucoma probability score (GPS), the HRT Moorfields regression analysis (MRA), scanning laser polarimetry (GDx enhanced corneal compensation; Glaucoma Diagnostics (GDx), Carl Zeiss Meditec, Dublin, CA) nerve fiber indicator (NFI), and Spectralis optical coherence tomography (OCT; Heidelberg Engineering) retinal nerve fiber layer (RNFL) classification. We defined abnormal tests as an automated classification of outside normal limits for HRT and OCT or NFI ≥ 56 (GDx). We conducted a sensitivity analysis, using borderline abnormal image classifications. The reference standard was clinical diagnosis by a masked glaucoma expert including standardized clinical assessment and automated perimetry. We analyzed 1 eye per patient (the one with more advanced disease). We also evaluated the performance according to severity and using a combination of 2 technologies. Main Outcome Measures Sensitivity and specificity, likelihood ratios, diagnostic, odds ratio, and proportion of indeterminate tests. Results We recruited 955 participants, and 943 were included in the analysis. The average age was 60.5 years (standard deviation, 13.8 years); 51.1% were women. Glaucoma was diagnosed in at least 1 eye in 16.8%; 32% of participants had no glaucoma-related findings. The HRT MRA had the highest sensitivity (87.0%; 95% confidence interval [CI], 80.2%–92.1%), but lowest specificity (63.9%; 95% CI, 60.2%–67.4%); GDx had the lowest sensitivity (35.1%; 95% CI, 27.0%–43.8%), but the highest specificity (97.2%; 95% CI, 95.6%–98.3%). The HRT GPS sensitivity was 81.5% (95% CI, 73.9%–87.6%), and

  17. Structural Magnetic Resonance Imaging Can Identify Trigeminal System Abnormalities in Classical Trigeminal Neuralgia

    PubMed Central

    DeSouza, Danielle D.; Hodaie, Mojgan; Davis, Karen D.

    2016-01-01

    Classical trigeminal neuralgia (TN) is a chronic pain disorder that has been described as one of the most severe pains one can suffer. The most prevalent theory of TN etiology is that the trigeminal nerve is compressed at the root entry zone (REZ) by blood vessels. However, there is significant evidence showing a lack of neurovascular compression (NVC) for many cases of classical TN. Furthermore, a considerable number of patients who are asymptomatic have MR evidence of NVC. Since there is no validated animal model that reproduces the clinical features of TN, our understanding of TN pathology mainly comes from biopsy studies that have limitations. Sophisticated structural MRI techniques including diffusion tensor imaging provide new opportunities to assess the trigeminal nerves and CNS to provide insight into TN etiology and pathogenesis. Specifically, studies have used high-resolution structural MRI methods to visualize patterns of trigeminal nerve-vessel relationships and to detect subtle pathological features at the trigeminal REZ. Structural MRI has also identified CNS abnormalities in cortical and subcortical gray matter and white matter and demonstrated that effective neurosurgical treatment for TN is associated with a reversal of specific nerve and brain abnormalities. In conclusion, this review highlights the advanced structural neuroimaging methods that are valuable tools to assess the trigeminal system in TN and may inform our current understanding of TN pathology. These methods may in the future have clinical utility for the development of neuroimaging-based biomarkers of TN. PMID:27807409

  18. Electrophysiologic abnormalities of children with ostium secundum atrial septal defect.

    PubMed

    Ruschhaupt, D G; Khoury, L; Thilenius, O G; Replogle, R L; Arcilla, R A

    1984-06-01

    Sinus node (SN) and atrioventricular node (AVN) function were evaluated in 49 patients with secundum type atrial septal defect (ASD). Automaticity and conduction system function were assessed by intracardiac recording of the AH and HV intervals at rest, corrected SN recovery time, sinoatrial conduction time, AVN refractory period and the ability of the AVN to conduct rapidly paced atrial beats to the ventricles. Electrophysiologic abnormalities were found in 41% of the 34 patients who were studied before surgery. However, no preoperative abnormalities were present in children younger than 2.5 years. If only children older than 2.5 years were analyzed, the incidence of conduction abnormalities was similar for the patients studied before operation (62%) and those studied after operation (71%). The size and ejection fractions of the right and left ventricles, the magnitude of shunt flow and the size of the ASD did not differ between the patients with and those without electrophysiologic abnormalities. AVN dysfunction was present in 40% of the patients who were studied after surgical repair. While this frequency was more than twice the preoperative incidence of AVN dysfunction, it was not statistically significant. The data suggest that patient age is the major factor that influences the presence of conduction system dysfunction in patients with ASD.

  19. Electrocardiograph abnormalities in intracerebral hemorrhage.

    PubMed

    Takeuchi, Satoru; Nagatani, Kimihiro; Otani, Naoki; Wada, Kojiro; Mori, Kentaro

    2015-12-01

    This study investigated the prevalence and type of electrocardiography (ECG) abnormalities, and their possible association with the clinical/radiological findings in 118 consecutive patients with non-traumatic, non-neoplastic intracerebral hemorrhage (ICH). ECG frequently demonstrates abnormalities in patients with ischemic stroke and subarachnoid hemorrhage, but little is known of ECG changes in ICH patients. Clinical and radiological information was retrospectively reviewed. ECG recordings that were obtained within 24 hours of the initial hemorrhage were analyzed. Sixty-six patients (56%) had one or more ECG abnormalities. The most frequent was ST depression (24%), followed by left ventricular hypertrophy (20%), corrected QT interval (QTc) prolongation (19%), and T wave inversion (19%). The logistic regression analysis demonstrated the following: insular involvement was an independent predictive factor of ST depression (p<0.001; odds ratio OR 10.18; 95% confidence interval [CI] 2.84-36.57); insular involvement (p<0.001; OR 23.98; 95% CI 4.91-117.11) and presence of intraventricular hemorrhage (p<0.001; OR 8.72; 95% CI 2.69-28.29) were independent predictive factors of QTc prolongation; deep hematoma location (p<0.001; OR 19.12; 95% CI 3.82-95.81) and hematoma volume >30 ml (p=0.001; OR 6.58; 95% CI 2.11-20.46) were independent predictive factors of T wave inversion. We demonstrate associations between ECG abnormalities and detailed characteristics of ICH.

  20. Neural Abnormalities in Nonallergic Rhinitis.

    PubMed

    Bernstein, Jonathan A; Singh, Umesh

    2015-04-01

    Sensory nerve endings within the airway epithelial cells and the solitary chemoreceptor cells, synapsing with sensory nerves, respond to airborne irritants. Transient receptor potential (TRP) channels (A1 and V1 subtypes, specifically) on these nerve endings initiate local antidromic reflexes resulting in the release of neuropeptides such as substance P and calcitonin G-related peptides. These neuropeptides dilate epithelial submucosal blood vessels and may therefore increase transudation across these vessels resulting in submucosal edema, congestion, and rhinitis. Altered expression or activity of these TRP channels can therefore influence responsiveness to irritants. Besides these pathogenic mechanisms, additional mechanisms such as dysautonomia resulting in diminished sympathetic activity and comparative parasympathetic overactivity have also been suggested as a probable mechanism. Therapeutic effectiveness for this condition has been demonstrated through desensitization of TRPV1 channels with typical agonists such as capsaicin. Other agents effective in treating nonallergic rhinitis (NAR) such as azelastine have been demonstrated to exhibit TRPV1 channel activity through the modulation of Ca(2+) signaling on sensory neurons and in nasal epithelial cells. Roles of antimuscarinic agents such as tiotropium in NAR have been suggested by associations of muscarinic cholinergic receptors with TRPV1. The associations between these channels have also been suggested as mechanisms of airway hyperreactivity in asthma. The concept of the united airway disease hypothesis suggests a significant association between rhinitis and asthma. This concept is supported by the development of late-onset asthma in about 10-40 % of NAR patients who also exhibit a greater severity in their asthma. The factors and mechanisms associating NAR with nonallergic asthma are currently unknown. Nonetheless, free immunoglobulin light chains and microRNA alteration as mediators of these inflammatory