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1.
Artigo em Inglês | MEDLINE | ID: mdl-38945734

RESUMO

Dentofacial deformity following juvenile idiopathic arthritis (JIA) with temporomandibular joint (TMJ) involvement is associated with functional, aesthetic, and psychosocial impairment. Corrective surgical treatment includes combinations of orthognathic surgeries (OS). The aims of this study were to assess orofacial symptoms, functional and aesthetic status, and stability after OS including mandibular distraction osteogenesis (MDO). A prospective study was conducted of 32 patients with JIA of the TMJ and dentofacial deformities who underwent MDO as the only surgery or in combination with bilateral sagittal split osteotomy, Le Fort I, and/or genioplastybetween 2003 and 2018. Data from clinical examinations and cephalograms performed pre- and postoperative and at long-term (mean 4 years) were analysed. Patients experienced unchanged orofacial symptoms (all P > 0.05), short-term TMJ functional impairment (all P < 0.001), and long-term morphological improvements in SNB angle (P < 0.001), anterior facial height (P < 0.001), mandibular length (P = 0.049), overjet (P < 0.001 and P = 0.005), and posterior facial symmetry (P = 0.046). MDO as the only surgery or with secondary adjunctive OS improved dentofacial morphology in terms of mandibular advancement, anterior facial height, posterior facial symmetry, and incisal relationships without long-term deterioration in TMJ function or orofacial symptoms.

2.
Rev Sci Instrum ; 95(4)2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38563720

RESUMO

The design, development, and successful implementation of pop-up Langmuir probes installed in the water-cooled divertor of W7-X are described. The probes are controlled by drive coils (actuators) installed behind the divertor plates. These drive coils make use of the magnetic field in W7-X to move the probe tips into and out of the plasma. The drive coils were installed in the vacuum vessel after extensively testing the durability of the coils and analyzing the criteria for safe operation. The probe design is carefully tailored for each of the 36 probe tips in order to be suitable for the different magnetic field configurations used in W7-X and ensure that the probes do not present leading edges to the magnetic flux tubes. An electronic bridge circuit is used for measurement to compensate for the effects of signal propagation time on the long cable lengths used. The diagnostic is integrated with the segment control of W7-X for automated operation and control of the diagnostic. The evaluation of the results from the plasma operation is presented after accounting for appropriate sheath expansion for negative bias voltage on the probes.

3.
NPJ Quantum Mater ; 8(1): 60, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38666239

RESUMO

FeSe1-xSx remains one of the most enigmatic systems of Fe-based superconductors. While much is known about the orthorhombic parent compound, FeSe, the tetragonal samples, FeSe1-xSx with x > 0.17, remain relatively unexplored. Here, we provide an in-depth investigation of the electronic states of tetragonal FeSe0.81S0.19, using scanning tunneling microscopy and spectroscopy (STM/S) measurements, supported by angle-resolved photoemission spectroscopy (ARPES) and theoretical modeling. We analyze modulations of the local density of states (LDOS) near and away from Fe vacancy defects separately and identify quasiparticle interference (QPI) signals originating from multiple regions of the Brillouin zone, including the bands at the zone corners. We also observe that QPI signals coexist with a much stronger LDOS modulation for states near the Fermi level whose period is independent of energy. Our measurements further reveal that this strong pattern appears in the STS measurements as short range stripe patterns that are locally two-fold symmetric. Since these stripe patterns coexist with four-fold symmetric QPI around Fe-vacancies, the origin of their local two-fold symmetry must be distinct from that of nematic states in orthorhombic samples. We explore several aspects related to the stripes, such as the role of S and Fe-vacancy defects, and whether they can be explained by QPI. We consider the possibility that the observed stripe patterns may represent incipient charge order correlations, similar to those observed in the cuprates.

4.
J Chem Phys ; 157(14): 144302, 2022 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-36243530

RESUMO

Laser-induced molecular alignment is well understood within the framework of the Born-Oppenheimer (BO) approximation. Without the BO approximation, however, the concept of molecular structure is lost, making it hard to precisely define alignment. In this work, we demonstrate the emergence of alignment from the first-ever non-BO quantum dynamics simulations, using the HD molecule exposed to ultrashort laser pulses as a few-body test case. We extract the degree of alignment from the non-BO wave function by means of an operator expressed in terms of pseudo-proton coordinates that mimics the BO-based definition of alignment. The only essential approximation, in addition to the semiclassical electric-dipole approximation for the matter-field interaction, is the choice of time-independent explicitly correlated Gaussian basis functions. We use a variational, electric-field-dependent basis-set construction procedure, which allows us to keep the basis-set dimension low while capturing the main effects of electric polarization on the nuclear and electronic degrees of freedom. The basis-set construction procedure is validated by comparing with virtually exact grid-based simulations for two one-dimensional model systems: laser-driven electron dynamics in a soft attractive Coulomb potential and nuclear rovibrational dynamics in a Morse potential.

5.
Anaesthesia ; 77(7): 751-762, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35302235

RESUMO

Although patient safety related to airway management has improved substantially over the last few decades, life-threatening events still occur. Technical skills, clinical expertise and human factors contribute to successful airway management. Checklists aim to improve safety by providing a structured approach to equipment, personnel and decision-making. This audit investigates adherence to our institution's airway checklist from 1 June 2016 to 31 May 2021. Inclusion criteria were procedures requiring airway management and we excluded all procedures performed solely under regional anaesthesia, sedation without airway management or paediatric and cardiovascular surgery. The primary outcome was the proportion of wholly performed pre-induction checklists. Secondary outcomes were the pattern of adherence over the 5 years well as details of airway management, including: airway management difficulties; time and location of induction; anaesthesia teams in operating theatres (including teams for different surgical specialities); non-operating theatre and emergency procedures; type of anaesthesia (general or combined); and urgency of the procedure. In total, 95,946 procedures were included. In 57.3%, anaesthesia pre-induction checklists were completed. Over the 5 years after implementation, adherence improved from 48.3% to 66.7% (p < 0.001). Anticipated and unanticipated airway management difficulties (e.g. facemask ventilation, supraglottic airway device or intubation) defined by the handling anaesthetist were encountered in 4.2% of all procedures. Completion of the checklist differed depending on the time of day (61.3% during the day vs. 35.0% during the night, p < 0.001). Completion also differed depending on location (66.8% in operating theatres vs. 41.0% for non-operating theatre anaesthesia, p < 0.001) and urgency of procedure (65.4% in non-emergencies vs. 35.4% in emergencies, p < 0.001). A mixed-effect model indicated that urgency of procedure is a strong predictor for adherence, with emergency cases having lower adherence (OR 0.58, 95%CI 0.49-0.68, p < 0.001). In conclusion, over 5 years, a significant increase in adherence to an anaesthesia pre-induction checklist was found, and areas for further improvement (e.g. emergencies, non-operating room procedures, night-time procedures) were identified.


Assuntos
Lista de Checagem , Emergências , Manuseio das Vias Aéreas/métodos , Anestesia Geral , Criança , Humanos , Salas Cirúrgicas
7.
Appl Microbiol Biotechnol ; 105(21-22): 8157-8193, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34625822

RESUMO

Quinones represent an important group of highly structurally diverse, mainly polyketide-derived secondary metabolites widely distributed among filamentous fungi. Many quinones have been reported to have important biological functions such as inhibition of bacteria or repression of the immune response in insects. Other quinones, such as ubiquinones are known to be essential molecules in cellular respiration, and many quinones are known to protect their producing organisms from exposure to sunlight. Most recently, quinones have also attracted a lot of industrial interest since their electron-donating and -accepting properties make them good candidates as electrolytes in redox flow batteries, like their often highly conjugated double bond systems make them attractive as pigments. On an industrial level, quinones are mainly synthesized from raw components in coal tar. However, the possibility of producing quinones by fungal cultivation has great prospects since fungi can often be grown in industrially scaled bioreactors, producing valuable metabolites on cheap substrates. In order to give a better overview of the secondary metabolite quinones produced by and shared between various fungi, mainly belonging to the genera Aspergillus, Penicillium, Talaromyces, Fusarium, and Arthrinium, this review categorizes quinones into families such as emodins, fumigatins, sorbicillinoids, yanuthones, and xanthomegnins, depending on structural similarities and information about the biosynthetic pathway from which they are derived, whenever applicable. The production of these quinone families is compared between the different genera, based on recently revised taxonomy. KEY POINTS: • Quinones represent an important group of secondary metabolites widely distributed in important fungal genera such as Aspergillus, Penicillium, Talaromyces, Fusarium, and Arthrinium. • Quinones are of industrial interest and can be used in pharmacology, as colorants and pigments, and as electrolytes in redox flow batteries. • Quinones are grouped into families and compared between genera according to the revised taxonomy.


Assuntos
Fusarium , Penicillium , Talaromyces , Aspergillus , Fungos , Humanos , Quinonas
8.
Rev Sci Instrum ; 92(8): 083510, 2021 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-34470385

RESUMO

Thoriated tungsten cathodes, first studied by Langmuir [Phys. Rev. 22, 357-398 (1923)], are used in many applications as efficient electron emitters. However, neutral pressure gauges with thoriated tungsten cathodes (or ASDEX pressure gauges) are not reliable when operated in the strong magnetic field of fusion devices of several Tesla. We have identified the reason for the bad performance in the Wendelstein 7-X stellarator during the operation of several 100 s. Not only were slow, creeping mechanical deformations of the cathodes observed, but also fast events, such as sudden short circuits. The temperature of the cathode is often much higher (about 2400 K) than the maximum value recommended by Langmuir [Phys. Rev. 22, 357-398 (1923)] (about 1900 K). Our test in a superconducting magnet revealed that for a long-pulse operation of 30 min or more in a 3.1 T field, there is an additional effect. We observed that the cathodes required a very high heating current after 6 h of operation. As a consequence, the possible temperature range of the thoriated tungsten cathodes became very small near to an experimentally determined failure limit. In fusion devices with long-pulse operation or in reactors, new cathode types must be used. We give a brief overview of alternative designs that are currently under development.

9.
Nature ; 596(7871): 221-226, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34381232

RESUMO

Research on magnetic confinement of high-temperature plasmas has the ultimate goal of harnessing nuclear fusion for the production of electricity. Although the tokamak1 is the leading toroidal magnetic-confinement concept, it is not without shortcomings and the fusion community has therefore also pursued alternative concepts such as the stellarator. Unlike axisymmetric tokamaks, stellarators possess a three-dimensional (3D) magnetic field geometry. The availability of this additional dimension opens up an extensive configuration space for computational optimization of both the field geometry itself and the current-carrying coils that produce it. Such an optimization was undertaken in designing Wendelstein 7-X (W7-X)2, a large helical-axis advanced stellarator (HELIAS), which began operation in 2015 at Greifswald, Germany. A major drawback of 3D magnetic field geometry, however, is that it introduces a strong temperature dependence into the stellarator's non-turbulent 'neoclassical' energy transport. Indeed, such energy losses will become prohibitive in high-temperature reactor plasmas unless a strong reduction of the geometrical factor associated with this transport can be achieved; such a reduction was therefore a principal goal of the design of W7-X. In spite of the modest heating power currently available, W7-X has already been able to achieve high-temperature plasma conditions during its 2017 and 2018 experimental campaigns, producing record values of the fusion triple product for such stellarator plasmas3,4. The triple product of plasma density, ion temperature and energy confinement time is used in fusion research as a figure of merit, as it must attain a certain threshold value before net-energy-producing operation of a reactor becomes possible1,5. Here we demonstrate that such record values provide evidence for reduced neoclassical energy transport in W7-X, as the plasma profiles that produced these results could not have been obtained in stellarators lacking a comparably high level of neoclassical optimization.

10.
Rev Sci Instrum ; 92(4): 043505, 2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-34243367

RESUMO

In nuclear fusion research, the effective ion charge Zeff, which characterizes the overall content of impurities, can be experimentally derived from the plasma electron-ion bremsstrahlung, given the electron density ne and temperature Te. At Wendelstein 7-X, a multichannel near-infrared spectrometer is installed to collect the plasma bremsstrahlung along 27 lines of sight covering more than half the plasma cross section, which provides information on Zeff over the entire plasma radius. To infer spatially resolved Zeff profiles, a Bayesian model is developed in the Minerva framework. Zeff, ne, and Te profiles are modeled as Gaussian processes, whose smoothness is determined by hyperparameters. These profiles are transformed to fields in Cartesian coordinates, given the poloidal magnetic flux surfaces calculated by the variational moments equilibrium code. Given all these physical quantities, the model predicts line-of-sight integrals of near-infrared bremsstrahlung spectra. The model includes the predictive (forward) models of the interferometer, Thomson scattering system, and visible and near-infrared spectrometers. Given the observations of all these diagnostics, the posterior probability distribution of Zeff profiles is calculated and shown as an inference solution. The smoothness (gradient) of the profiles is optimally chosen by Bayesian Occam's razor. Furthermore, wall reflections can significantly pollute the measurements of the plasma bremsstrahlung, which leads to over-estimation of Zeff values in the edge region. In the first results presented in this work, this problem does not appear, and the posterior samples of Zeff profiles are overall plausible and consistent with Zeff values inferred, given the data from the single-channel visible spectrometer.

12.
Clin Neurophysiol ; 132(8): 1974-1981, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34020890

RESUMO

OBJECTIVE: To investigate the peripheral nerve and muscle function electrophysiologically in patients with persistent neuromuscular symptoms following Coronavirus disease 2019 (COVID-19). METHODS: Twenty consecutive patients from a Long-term COVID-19 Clinic referred to electrophysiological examination with the suspicion of mono- or polyneuropathy were included. Examinations were performed from 77 to 255 (median: 216) days after acute COVID-19. None of the patients had received treatment at the intensive care unit. Of these, 10 patients were not even hospitalized. Conventional nerve conduction studies (NCS) and quantitative electromyography (qEMG) findings from three muscles were compared with 20 age- and sex-matched healthy controls. RESULTS: qEMG showed myopathic changes in one or more muscles in 11 patients (55%). Motor unit potential duration was shorter in patients compared to healthy controls in biceps brachii (10.02 ± 0.28 vs 11.75 ± 0.21), vastus medialis (10.86 ± 0.37 vs 12.52 ± 0.19) and anterior tibial (11.76 ± 0.31 vs 13.26 ± 0.21) muscles. All patients with myopathic qEMG reported about physical fatigue and 8 patients about myalgia while 3 patients without myopathic changes complained about physical fatigue. CONCLUSIONS: Long-term COVID-19 does not cause large fibre neuropathy, but myopathic changes are seen. SIGNIFICANCE: Myopathy may be an important cause of physical fatigue in long-term COVID-19 even in non-hospitalized patients.


Assuntos
COVID-19/complicações , COVID-19/fisiopatologia , Fadiga/etiologia , Fadiga/fisiopatologia , Doenças Musculares/etiologia , Doenças Musculares/fisiopatologia , Adulto , Idoso , COVID-19/diagnóstico , Eletromiografia/tendências , Fadiga/diagnóstico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Doenças Musculares/diagnóstico , Condução Nervosa/fisiologia , Sistema de Registros , Fatores de Tempo
13.
Clin Neurophysiol ; 132(6): 1347-1357, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33676846

RESUMO

OBJECTIVE: To investigate the sensitivity of muscle velocity recovery cycles (MVRCs) for detecting altered membrane properties in critically ill patients, and to compare this to conventional nerve conduction studies (NCS) and quantitative electromyography (qEMG). METHODS: Twenty-four patients with intensive care unit acquired weakness (ICUAW) and 34 healthy subjects were prospectively recruited. In addition to NCS (median, ulnar, peroneal, tibial and sural nerves) and qEMG (biceps brachii, vastus medialis and anterior tibial muscles), MVRCs with frequency ramp were recorded from anterior tibial muscle. RESULTS: MVRC and frequency ramp parameters showed abnormal muscle fiber membrane properties with up to 100% sensitivity and specificity. qEMG showed myopathy in 15 patients (63%) while polyneuropathy was seen in 3 (13%). Decreased compound muscle action potential (CMAP) amplitude (up to 58%) and absent F-waves (up to 75%) were frequent, but long duration CMAPs were only seen in one patient with severe myopathy. CONCLUSIONS: Altered muscle fiber membrane properties can be detected in patients with ICUAW not yet fulfilling diagnostic criteria for critical illness myopathy (CIM). MVRCs may therefore serve as a tool for early detection of evolving CIM. SIGNIFICANCE: CIM is often under-recognized by intensivists, and large-scale longitudinal studies are needed to determine its incidence and pathogenesis.


Assuntos
Músculo Esquelético/fisiopatologia , Doenças Musculares/diagnóstico , Condução Nervosa/fisiologia , Adulto , Idoso , Estado Terminal , Diagnóstico Precoce , Eletromiografia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Doenças Musculares/fisiopatologia , Sensibilidade e Especificidade
14.
Scand J Urol ; 55(2): 169-176, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33635171

RESUMO

OBJECTIVE: Overactive bladder (OAB) affects hundreds of millions of people worldwide and has significant detrimental effects on quality-of-life. Percutaneous tibial nerve stimulation (PTNS) is endorsed in the European guidelines of Urology as second-line therapy - on par with pharmacological treatment for women with OAB. METHODS: This prospective cohort study describes our clinical experience with PTNS in a daily outpatient clinic, on a consecutive cohort. The cohort of 116 patients was mixed; including both men and women with idiopathic (iOAB) and neurogenic (nOAB) overactive bladder. Patients were treated with a 12-week course of PTNS followed by monthly maintenance treatment. Data were collected during 4 years. RESULTS: The most common indication for PTNS was OAB with urge incontinence (53%) followed by OAB-dry and nocturia (both 16%). One hundred and ten (95%) patients completed follow-up and 68 patients (62%) continued to maintenance treatment. A total of 68 patients reported an effect on PROM, BD and ICIQ-OAB, which is the same 62% that continue in maintenance PTNS. A significant decline was seen in overall ICIQ-OAB score, with a median drop from 87 to 54, a significant decline in overall frequency and nocturia on bladder diary and a shift in pad test group in 19% of the incontinence patients. CONCLUSION: PTNS shows an equally significant effect on men as well as women both in the iOAB and nOAB subgroups in a daily outpatient clinic. In our opinion, PTNS should be a standard treatment option available at urological departments, where both men and women in both sub-groups could benefit from treatment. Further randomized studies focusing on men with iOAB are needed.


Assuntos
Nervo Tibial , Estimulação Elétrica Nervosa Transcutânea , Bexiga Urinária Hiperativa , Adulto , Idoso , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Resultado do Tratamento , Bexiga Urinária Hiperativa/etiologia , Bexiga Urinária Hiperativa/terapia
15.
Rev Sci Instrum ; 92(12): 123504, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34972413

RESUMO

Preliminary experiments have been performed toward the development of a multi-cell Penning-Malmberg trap for the storage of large numbers of positrons (≥1010 e+). We introduce the master-cell test trap and the diagnostic tools for first experiments with electrons. The usage of a phosphor screen to measure the z-integrated plasma distribution and the number of confined particles is demonstrated, as well as the trap alignment to the magnetic field (B = 3.1 T) using the m = 1 diocotron mode. The plasma parameters and expansion are described along with the autoresonant excitation of the diocotron mode using rotating dipole fields and frequency chirped sinusoidal drive signals. We analyze the reproducibility of the excitation and use these findings to settle on the path for the next generation multi-cell test device.

16.
Int J Colorectal Dis ; 35(9): 1663-1671, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32671458

RESUMO

PURPOSE: In most cases, squamous cell carcinoma of the anus (SCCA) is treated with chemo-radiotherapy preserving sphincter function and offering good long-term survival and low recurrence rates. However, chemo-radiotherapy has several side effects: dyspareunia, impotence, fecal incontinence, pain, and skin symptoms. Small/T1 tumors, without metastatic disease, can be treated with local excision alone. We aimed to systematically review the literature regarding outcome following local excision of T1 SCCA. METHODS: PubMed and Embase databases were searched for studies that investigated outcome following local excision of SCCA. RESULTS: Twenty-three studies were included. Twenty of the studies were retrospective, and three studies included more than 100 patients. Most of the studies were published before the 1980s. Overall there was great heterogeneity and missing data across the included studies when comparing patient demographics, resection margins, definitions on tumor location, and outcome. Overall 5-year survival was 69% (95% CI 66-72) following local excision. Overall 5-year recurrence was 37% (95% CI 30-45) following local excision. No complications were reported following local excision. CONCLUSION: The current literature on outcome following local excision of T1 anal cancers consists predominantly of smaller, retrospective, and heterogenous studies. Overall 5-year survival is acceptable, but worse than following chemo-radiation therapy. However, local excision seems to have no or only few minor complications. Recurrence rates are high. Therefore, a thorough follow-up program is needed when performing local excision as primary treatment for T1 SCCA. There is an evident need for further studies.


Assuntos
Neoplasias do Ânus , Procedimentos Cirúrgicos do Sistema Digestório , Neoplasias Retais , Canal Anal/patologia , Neoplasias do Ânus/patologia , Neoplasias do Ânus/cirurgia , Feminino , Humanos , Masculino , Recidiva Local de Neoplasia , Estadiamento de Neoplasias , Neoplasias Retais/patologia , Estudos Retrospectivos , Resultado do Tratamento
18.
Rev Sci Instrum ; 91(4): 043507, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-32357734

RESUMO

As a magnetic confinement configuration for electron-positron pair-plasmas, the APEX collaboration [T. S. Pedersen et al., New J. Phys. 14, 035010 (2012)] plans to construct a compact levitated dipole experiment with a high-temperature superconducting coil. In order to realize stable levitation of the dipole field coil, a simple feedback-controlled levitation system was constructed with conventional analog circuits. We report the properties of a prototype levitation system using a permanent magnet and compare its behavior to predictions from a stability analysis. We also present a practical review needed for the construction of a compact levitated dipole trap system based on the work of Morikawa et al. [Teion Kogaku, J. Cryo. Soc. Jpn. 39, 209 (2004)]. Numerical orbit analysis suggests improved confinement properties of charged particles in a dipole field trap by replacing the permanent magnet with a levitated superconducting coil magnet. Such a compact dipole field configuration is potentially applicable to the confinement of various charged particles including positrons and electrons.

19.
Phys Rev Lett ; 123(2): 025002, 2019 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-31386539

RESUMO

For the first time, the optimized stellarator Wendelstein 7-X has operated with an island divertor. An operation regime in hydrogen was found in which the total plasma radiation approached the absorbed heating power without noticeable loss of stored energy. The divertor thermography recorded simultaneously a strong reduction of the heat load on all divertor targets, indicating almost complete power detachment. This operation regime was stably sustained over several energy confinement times until the preprogrammed end of the discharge. The plasma radiation is mainly due to oxygen and is located at the plasma edge. This plasma scenario is reproducible and robust at various heating powers, plasma densities, and gas fueling locations. These experimental results show that the island divertor concept actually works and displays good power dissipation potential, producing a promising exhaust concept for the stellarator reactor line.

20.
Clin Neurophysiol ; 130(9): 1520-1527, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31295721

RESUMO

OBJECTIVE: To examine muscle membrane properties in neurogenic muscles using Muscle Velocity Recovery Cycles (MVRCs). METHODS: Forty-seven patients referred to Nerve Conduction Studies (NCS) and Electromyography (EMG) for peroneal nerve entrapment neuropathy were prospectively included. The patients were categorized as peroneal nerve entrapment neuropathy across knee (n = 22), L5-radiculapathy (n = 10), normal NCS/EMG (n = 9) and other disorders (n = 6) using NCS/EMG and neuroimaging results. Strength in anterior tibial muscle was measured by Medical Council Scale (MRC) and disease duration was recorded. In addition to conventional NCS/EMG, all subjects were examined with MVRCs in anterior tibial muscle. This provided parameters of muscle relative refractory period (MRRP) and early supernormality (ESN) and late supernormality (LSN). The results were compared with 29 age-matched healthy control subjects. RESULTS: MRRP was prolonged and ESN and LSN were reduced in neurogenic muscles. MRRP, ESN and LSN correlated to MRC and incidence of spontaneous activity but not to motor unit potential parameters or disease duration. CONCLUSIONS: MVRC changes provide in vivo evidence of depolarization in intact human muscle fibres that could underlie reduced muscle excitability and hence weakness in neurogenic muscles. SIGNIFICANCE: MVRCs appear to be a useful technique for revealing disease mechanism in a broad range of neuromuscular diseases.


Assuntos
Músculo Esquelético/fisiopatologia , Neuropatias Fibulares/fisiopatologia , Radiculopatia/fisiopatologia , Período Refratário Eletrofisiológico/fisiologia , Estudos de Casos e Controles , Eletromiografia , Feminino , Humanos , Vértebras Lombares , Masculino , Pessoa de Meia-Idade , Fibras Musculares Esqueléticas/fisiologia , Força Muscular/fisiologia , Debilidade Muscular/fisiopatologia , Condução Nervosa/fisiologia , Estudos Prospectivos
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